Дисертації: "Qualityof hydrodynamics"

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Денисенко, Владислав Русланович. "Гідродинаміка неоднорідного псевдозрідження". Master's thesis, Київ, 2019. https://ela.kpi.ua/handle/123456789/27646.

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Об’єкт дослідження: гідродинаміка при пульсаційному псевдозрідженні. Предмет дослідження: якісні характеристики гідродинаміки неоднорідного псевдозрідження при грануляції. Метою роботи є встановлення закономірностей процесу неоднорідного струменево-пульсаційного псевдозрідження в автоколивальному режимі при підвищених висотах шару зернистого матеріалу та розроблення методики розрахунку промислових апаратів для грануляції. Сформульовано принцип взаємодії газового суцільного середовища із зернистим матеріалом для реалізації струменево-пульсаційного режиму псевдозрідження при Zf/H₀≤0,21. Експериментально визначено порозності в зонах камери гранулятора при неоднорідному псевдозрідженні в автоколивальному режимі при п’ятикратному перевищенню висоти нерухомого шару H₀ висоти пробою газового струменя Zf. Експериментально досліджено вплив висоти зернистого матеріалу на динаміку зміни порозності та індекс перемішування в базових зонах апарату. Підтверджено дослідженнями, що процес грануляції при застосуванні неоднорідного струменево-пульсаційного псевдозрідження за підвищених висот шару зернистого матеріалу призводить до інтенсифікації тепломасообмінних процесів в 1,6 рази в порівнянні із барботажним.
The object of the research: the hydrodynamics during the pulsation fluidization. The subject of the research: quality characteristics of hydrodynamics of nonuniform fluidization during the granulation process. The aim of the work is establishment of the regularities of the process of non-uniform fluidization in the application of pulsation in self-oscillating mode at elevated height of a layer of granular material and development of methods of calculation of industrial machines. Formulated the principle of interaction of a gas continuous medium with a granular material for the realization of jet pulsation mode of fluidization in Zf/H₀≤0,21. Experimentally determined voids in the areas of camera granulator in self-oscillating mode of fluidization when a fivefold excess of the height of the fixed bed height H₀ of the breakdown of the gas jet Zf. Experimentally investigated the influence of the height of granular material at the dynamics of void and the index of mixing in the core zones of the apparatus. The study proves that the granulation process in the application of a nonuniform jet-pulsed fluidization at elevated heights of a layer of granular material leads to intensification of heat and mass transfer processes in 1,6 times in comparison with barbotine.
Объект исследования: гидродинамика при пульсационном псевдоожижении. Предмет исследования: качественные характеристики гидродинамики неоднородного псевдоожижения при грануляции. Целью работы является установление закономерностей процесса неоднородного струйно-пульсационного псевдоожижения в автоколебательном режиме при повышенных высотах слоя зернистого материала и разработка методики расчета промышленных аппаратов для грануляции. Сформулирован принцип взаимодействия газовой сплошной среды с зернистым материалом для реализации струйно-пульсационного режима псевдоожижения при Zf/H₀≤0,21. Экспериментально определено порозности в зонах камеры гранулятора при неоднородном псевдоожижении в автоколебательном режиме при пятикратном превышению высоты неподвижного слоя H₀ высоты пробоя газового факела Zf. Экспериментально исследовано влияние высоты зернистого материала на динамику изменения порозности и индекс перемешивания в базовых зонах аппарата. Подтверждено исследованиями, что процесс грануляции при применении неоднородного струйно-пульсационного псевдоожижения при повышенных высотах слоя зернистого материала приводит к интенсификации тепломассообменных процессов в 1,6 раза в сравнении с барботажним.

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Holmvall, Martin. "Nip Mechanics, Hydrodynamics and Print Quality in Flexo Post-Printing." Doctoral thesis, Mittuniversitetet, Institutionen för naturvetenskap, teknik och matematik, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:miun:diva-11347.

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Chen, Yiping. "Numerical modelling of solute transport processes using higher order accurate finite difference schemes : numerical treatment of flooding and drying in tidal flow simulations and higher order accurate finite difference modelling of the advection diffusion equation for solute transport predictions." Thesis, University of Bradford, 1992. http://hdl.handle.net/10454/4344.

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The modelling of the processes of advection and dispersion-diffusion is the most crucial factor in solute transport simulations. It is generally appreciated that the first order upwind difference scheme gives rise to excessive numerical diffusion, whereas the conventional second order central difference scheme exhibits severe oscillations for advection dominated transport, especially in regions of high solute gradients or discontinuities. Higher order schemes have therefore become increasingly used for improved accuracy and for reducing grid scale oscillations. Two such schemes are the QUICK (Quadratic Upwind Interpolation for Convective Kinematics) and TOASOD (Third Order Advection Second Order Diffusion) schemes, which are similar in formulation but different in accuracy, with the two schemes being second and third order accurate in space respectively for finite difference models. These two schemes can be written in various finite difference forms for transient solute transport models, with the different representations having different numerical properties and computational efficiencies. Although these two schemes are advectively (or convectively) stable, it has been shown that the originally proposed explicit QUICK and TOASOD schemes become numerically unstable for the case of pure advection. The stability constraints have been established for each scheme representation based upon the von Neumann stability analysis. All the derived schemes have been tested for various initial solute distributions and for a number of continuous discharge cases, with both constant and time varying velocity fields. The 1-D QUICKEST (QUICK with Estimated Streaming Term) scheme is third order accurate both in time and space. It has been shown analytically and numerically that a previously derived quasi 2-D explicit QUICKEST scheme, with a reduced accuracy in time, is unstable for the case of pure advection. The modified 2-D explicit QUICKEST, ADI-TOASOD and ADI-QUICK schemes have been developed herein and proved to be numerically stable, with the bility sta- region of each derived 2-D scheme having also been established. All these derived 2-D schemesh ave been tested in a 2-D domain for various initial solute distributions with both uniform and rotational flow fields. They were further tested for a number of 2-D continuous discharge cases, with the corresponding exact solutions having also been derived herein. All the numerical tests in both the 1-D and 2-D cases were compared with the corresponding exact solutions and the results obtained using various other difference schemes, with the higher order schemes generally producing more accurate predictions, except for the characteristic based schemes which failed to conserve mass for the 2-D rotational flow tests. The ADI-TOASOD scheme has also been applied to two water quality studies in the U. K., simulating nitrate and faecal coliform distributions respectively, with the results showing a marked improvement in comparison with the results obtained by the second order central difference scheme. Details are also given of a refined numerical representation of flooding and drying of tidal flood plains for hydrodynamic modelling, with the results showing considerable improvements in comparison with a number of existing models and in good agreement with the field measured data in a natural harbour study.

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Goodhue, Nigel David. "Hydrodynamic and water quality modelling of the lower Kaituna River and Maketu Estuary /." The University of Waikato, 2007. http://hdl.handle.net/10289/2375.

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The Maketu Estuary is a shallow intertidal estuary (2.3 km2) located in the Bay of Plenty, North Island, New Zealand. The Kaituna River contributes the largest freshwater flow into the estuary through control gates. Lake Rotoiti and indirectly Lake Rotorua supply the base flow to the Kaituna River, with tributaries along the 50 km reach also significantly contributing to the flow. Water quality within the river is affected by elevated nutrients, faecal coliforms, high oxygen demand and algae concentrations derived from the lakes as well as contributions from tributaries and industrial and urban discharge. Through the use of a coupled hydrodynamic-biogeochemical numerical model ELCOM-CAEDYM, this study aims to examine the nutrient, phytoplankton and hydrodynamics of the Maketu Estuary and lower Kaituna River. Water quality and hydrodynamic measurements were sourced from Environment Bay of Plenty's data archives as well as a number of instrument deployments to collect water velocity, tidal elevation and salinity and temperature measurements during the course of this study. Included in the field work was a survey of the lower river and estuary bathymetry. Model simulations predicted that the maximum residence time in the Maketu Estuary is 1.5 days, occurring in the inner western region. Residence time in the lower river (mouth to 8.5 km upstream) is in the order of hours although some variations were predicted near the river mouth. Growth rates of four phytoplankton groups where assessed over a 15 day period in January 2004. In the Kaituna River ELCOM-CAEDYM predicted that the community growth rates were small with the exception of a slight increase in biomass of the two freshwater groups in a semi-detached river bend. The increase in the loop was correlated with an increase of residence time. In the estuary, marine diatoms showed the highest growth rates in the western region which is expected to relate to retention time and available nutrients. Dinoflagellates showed the smallest variation in predicted growth rates, most likely due to their broad salinity tolerance. The two freshwater species showed a reduction in abundance when mixed with marine water. A principle limiting factor to phytoplankton growth in both the river and estuary is the low residence time. A number of scenarios were simulated in the river and estuary by altering the forcing conditions in the model. A simulation of the increased nutrient load associated with the Rotoiti diversion wall revealed that phytoplankton growth in the river and estuary will not be significantly affected. Because of the close proximity of the control gates to the river mouth, a proportion of water drawn through the structure can be marine. By opening the old river channel, model simulations predicted that a reduction in salinity would be possible, however the outcome of complete freshwater is probably not achievable. Increasing the discharge volume from the river into the estuary was also simulated. The results indicated that increasing the freshwater inflow at Fords Cut would reduce the salinity in the estuary while increasing the net (residual) flow towards the estuary mouth. Increasing the flow would also result in a greater range of salinity in regions of the estuary. Changing the inflow location to the historic Papahikahawai Channel also affected the salinity in the estuary. The most significant effect of an inflow at this location was a reduction of the residual currents in the western region of the estuary.

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Shojaei, Nasim. "Automatic Calibration of Water Quality and Hydrodynamic Model (CE-QUAL-W2)." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1942.

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One of the most important purposes of surface water resource management is to develop predictive models to assist in identifying and evaluating operational and structural measures for improving water quality. To better understand the effects of external and internal nutrient and organic loading and the effects of reservoir operation, a model is often developed, calibrated, and used for sensitivity and management simulations. The importance of modeling and simulation in the scientific community has drawn interest towards methods for automated calibration. This study addresses using an automatic technique to calibrate the water quality model CE-QUAL-W2 (Cole and Wells, 2013). CE-QUAL-W2 is a two-dimensional (2D) longitudinal/vertical hydrodynamic and water quality model for surface water bodies, modeling eutrophication processes such as temperature-nutrient-algae-dissolved oxygen-organic matter and sediment relationships. The numerical method used for calibration in this study is the particle swarm optimization method developed by Kennedy and Eberhart (1995) and inspired by the paradigm of birds flocking. The objective of this calibration procedure is to choose model parameters and coefficients affecting temperature, chlorophyll a, dissolved oxygen, and nutrients (such as NH4, NO3, and PO4). A case study is presented for the Karkheh Reservoir in Iran with a capacity of more than 5 billion cubic meters that is the largest dam in Iran with both agricultural and drinking water usages. This algorithm is shown to perform very well for determining model parameters for the reservoir water quality and hydrodynamic model. Implications of the use of this procedure for other water quality models are also shown.

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Tang, Ling 1963. "Interfacing hydrodynamic and water quality models with the Eulerian-Lagrangian method." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9637.

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Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1998.
Includes bibliographical references.
The problem of interfacing hydrodynamic and water quality models is investigated with emphasis on modeling efficiency, accuracy and flexibility. An Eulerian-Lagrangian type of transport model is proposed for interfacing due to its superior simulation efficiency and numerical resolution in advection dominant flows. Comparisons are made between Eulerian models and Eulerian-Lagrangian models through both theoretical analyses and numerical studies of mass conservation and concentration accuracy. A mass conservative model, such as an Eulerian type model, will not necessarily guarantee concentration accuracy. As part of this research, a three dimensional EulerianLagrangian transport model (ELM3D) is developed and validated. The interfacing efficiency of ELM3D is demonstrated through a series of numerical tracer studies simulating the future outfall in Massachusetts Bay. Comparison against a traditional Eulerian model, ECOMsi, shows that an Eulerian-Lagrangian interfacing with a proper mass correction technique, such as total mass scaling, can serve as an efficient transport tool, which is more robust than conventional Eulerian Models in dealing with advection dominant flows.
by Ling Tang.
Ph.D.

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Hashim, Noor Baharim. "Watershed, hydrodynamic, and water quality models for total maximum daily load St. Louis Bay watershed Mississippi." Diss., Mississippi State : Mississippi State University, 2001. http://library.msstate.edu/etd/show.asp?etd=etd-04102001-154624.

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Nitsche, N. C. "Assessment of a hydrodynamic water quality model, DUFLOW, for a winter rainfall river." Thesis, Stellenbosch : Stellenbosch University, 2000. http://hdl.handle.net/10019.1/51624.

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Thesis (MEng)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: The Berg River is one of the largest rivers in the winter rainfall area of the Western Cape and is one of the most important water supply sources of the area. The Riviersonderend-Berg system needs to be expanded in order to meet increasing water demands of the Greater Cape Town (GCT) region. The implementation of future schemes will remove additional fresh water from the Berg River main stem, which will give rise to increased nutrient levels and higher salinity in the water. A water quality information system (WQIS) has been proposed to benefit the management of water resources, the flow quantity and the quality of the water. A part of this WQIS will be a water-quality simulation model that characterizes the water quality situation and is able to predict water quality responses to future implementations, as well as simulate different scenarios that can be used for management purposes. The objective of this study is to represent the water quality situation of the Berg River in a simulation model by implementing, testing and verifying a water quality simulation model, and assembling a hydraulic and water quality database suitable to meet foregoing objectives. This study firstly examined the water quality variables of concern: pH, Total Dissolved Salts (TDS) and phosphates to develop an understanding of the water quality responses and causes of the main stem of the Berg River system. A thorough review of the available models has been undertaken in the light of certain selection criteria, before determining that DUFLOW would be an acceptable model for this study. The water quality variables that have been modelled are TDS, Phosphates as P04, Oxygen and Temperature. As no predefined module simulating temperature, TDS and COD was included; these algorithms, describing the processes of these water quality variables have been additionally coded. The coding was possible, as DUFLOW' s water quality module consists of an open structure. The predefined water quality module was simplified to only include the water quality process algorithms, for water quality variables where data was available. Unfortunately, phosphates were mainly simulated on advection, and the influence of all the additional processes could not be assessed. All data gathering and preparation for the model had to be completed before commencing the model configuration. This included information on cross-sections, historical flow records, bridges and weirs for the hydraulic component ofDUFLOW. For the water quality module, information on historical grab samples has been obtained and 'infilled' to provide daily time series. To simulate the water quality in a river as accurately as possible, the flow simulation needs to be accurate. Ungauged subcatchment runoff was added to the simulation model to improve the correspondence between the simulated and the measured flow. Calibration of the water quality part of DUFLOW was completed by adjusting the different parameters after a sensitivity analysis. The model was verified by using a different time period than for the configuration, to ensure that an independent data set has been used. After configuring, calibrating and verifying the model, the applicability of the model could be tested for different scenario runs. Three scenarios were chosen according to real situations: • a short term effluent spill, with and without water releases from an upstream source (either Skuifraam Dam or Voëlvlei Dam); • the impact on the flow and water quality situation of the river when an upstream dam is built; • a long term management control scenario, that analyses load or concentration releases into the river according to limitations upstream and downstream of the discharge location. The scenario analysis provides an opportunity to assess the applicability of DUFLOW to simulate real time management and operational issues in a river and to aid in management decisions.
AFRIKAANSE OPSOMMING: Die Bergrivier is een van die grootste riviere in die winterreënvalgebied van die Weskaap en is een van die mees belangrike waterverskaffingsbronne in die area. Die Riviersonderend-Bergrivier-stelsel moet uitgebrei word om aan die groeiende waterbehoefte van die groter Kaapse Metropolitaanse Area te voldoen. Die implementering van toekomstige skemas sal addisionele vars water uit die hoof-loop van die Bergrivier onttrek, wat tot hoër voedingstof-vlakke en soutgehalte in die water sal lei. 'n Waterkwaliteitsinformasiestelsel (WQIS) sal van nut wees om die vloei-omvang en waterkwaliteit van waterbronne te bestuur. 'n Deel van die WQIS sal 'n waterkwaliteit-simulasiemodel wees, wat die waterkwaliteitsituasie sal kan ontleed, waterkwaliteit-reaksies op toekomstige implementerings kan voorspel, asook verskeie scenarios vir bestuursdoeleindes kan simuleer. Hierdie studie behandel spesifiek die waterkwaliteitsveranderlikes pH, totale opgeloste soute, fosfate, temperatuur en suurstof om 'n begrip te ontwikkel van die waterkwaliteitsreaksies en oorsake van die hoofloop van die Bergriviersisteem. Die doelwit van hierdie studie is om die waterkwaliteitsituasie van die Bergrivier uit te beeld deur die implementering, toets en kalibrasie van 'n waterkwaliteit-simulasie model, asook die insameling van hidrouliese- en waterkwaliteitsdata om aan bogenoemde doelwitte te voldoen. 'n Reeks beskikbare modelle is deeglik ondersoek voordat besluit is dat die DUFLOW model 'n gepaste model vir hierdie spesifieke studie is. Die keuse was gebaseer op spesifieke vereistes wat as belangrik beskou is deur potensiële bestuursgeorienteerde gebruiksgroepe. Die waterkwaliteitsveranderlikes wat gemodelleer is, is totale opgeloste soute, fosfate as P04, suurstof en temperatuur. Omdat geen voorgegewe temperatuur-, TDS- en COD modules in die model ingesluit is nie, is die algoritmes wat die prosesse van hierdie waterkwaliteitsveranderlikes beskryf, addisioneel gekodeer. Die kodering is moontlik gemaak deur die oop struktuur van DUFLOW se waterkwaliteitsmodule. Die voorgegewe waterkwaliteitsmodule is vereenvoudig om alleenlik die waterkwaliteit proses-algoritmes in ag te neem wanneer data vir waterkwaliteitsveranderlikes beskikbaar was. Ongelukkig is die fosfate hoofsaaklik op beweging gesimuleer, en die invloed van alle addisionele prosesse kon nie getoets word nie. Alle data-insameling en -voorbereidings vir die model moes voltooi word, voordat begin kon word met die opstel van die simulasie-model. Dit het inligting oor dwarssnitte, historiese vloeirekords, brik en keerwalle vir die hidrouliese komponent van DUFLOW ingesluit. Vir die waterkwaliteitsmodule is inligting van historiese bemonstering verkry en ingevulom 'n daaglikse tydreeks te verkry. Om die water-kwaliteit van 'n rivier so akkuraat as moontlik te simuleer, moet die vloei-simulasie redelik akkuraat wees. Ongemete sub-opvanggebied afloop is bygetel om die korrelasie tussen die gesimuleerde en gemete vloei te verbeter. Kalibrasie van die waterkwaliteitmodule van DUFLOW is voltooi deur die verskillende parameters te verstel na 'n sensitiwiteits-analise. Die model is geverifieer deur 'n ander tydperiode as die vir die opstel te gebruik, om sodoende te verseker dat Inonafhanklike data stel gebruik word. Na die opstel, kalibrasie en verifiering van die model, kon dit toegepass word vir verskillende bestuursscenanos. Drie scenarios is na aanleiding van werklike situasies gekies: 'n korttermyn uitvloeisel storting-situasie met en sonder loslatings van 'n stroomop bron (Of Skuifraamdam Of Voëlvleidam), die impak op die vloei- en waterkwaliteitsituasie van die rivier sou 'n dam stroomop gebou word. 'n langtermyn bestuurs-scenario waarin die lading en konsentrasies, veroorsaak deur die loslatings vanuit die dam na die rivier, ontleed word na aanleiding van beperkings stroomop en -af van die loslatingsplek. Die analise van die scenarios verskaf 'n geleentheid om die toepaslikheid van DUFLOW te ondersoek om werklike operasionele aangeleenthede te simuleer en om sodoende bestuursbesluite te vergemaklik.

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Qian, Aiguo, and 乾愛國. "Three-dimensional modelling of hydrodynamics and tidal flushing in Deep Bay." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B29799004.

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Takkouk, Saddek. "Applications of hydrodynamic and water quality models to the Sau and Boadella Reservoirs." Doctoral thesis, Universitat de Girona, 2011. http://hdl.handle.net/10803/31853.

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Applicaciò d'un model de hydrodinàmica i de qualitat de l'aigua als embassaments de Sau i Boadella
The aim of this work is to have an idea about the behaviour of Sau and Boedella reservoirs in term of hydrodynamic and water quality, the models applied for are Dynamic simulation model DYRESM and water quality model CAEDYM.
En la tesi s'ha aplicat el model de qualitat de l'aigua DYREM-CAEDYM als embassaments de Sau i Boadella. Els models de qualitat de l'aigua són capaços de predir l'evolució física, química i biològica dels embassaments. Un cop inicialitzats i calibrats ens poden donar informació de com evolucionarà, per exemple, el fòsfor dissolt i les poblacions d'algues. Per funcionar, aquests models necessiten nodrir-se diàriament amb dades meteorològiques com ara la radiació solar, la velocitat del vent o les precipitacions, les quals es poden obtenir d'estacions meteorològiques properes als embassaments. També calen dades biològiques que han estat facilitades per diferents persones i organismes com el Departament d'Ecologia de la Universitat de Barcelona i l'Agència Catalana de l'Aigua. Aquests models no són fàcils de manejar i el primer que s'ha de fer és estudiar-ne la seva aplicabilitat. Concretament, cal saber si poden ser d'una dimensió o en cal un nombre superior. Això es fa comprovant l'evolució de diferents nombres adimensionals, com per exemple els de Wedderburn i Burger. Un cop calibrat, el model DYRESM-CAEDYM prediu -molt bé- l'evolució de la temperatura i -bastant bé- la de l'oxigen dissolt, sobretot a l'embassament de Sau,indicant la presència de zones anòxiques al fons. La tendència en l'evolució del fòsfor dissolt també s'hi veu ben reflectida. En canvi, les simulacions de la clorofila-a, indicativa de les algues, no són tan acurades ja que depenen de molt factors, alguns dels quals no queden prou reflectits en el model. L'objectiu final de la tesi és poder millorar la gestió dels embasaments indicant, per exemple, quina és la fondària òptima d'extracció de l'aigua.

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Boegman, Leon. "Application of a two-dimensional hydrodynamic and water quality model to Lake Erie." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape8/PQDD_0005/MQ46066.pdf.

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Van, Glubt Sarah. "Hydrodynamic and Water Quality Modeling of the Chehalis River Using CE-QUAL-W2." PDXScholar, 2017. https://pdxscholar.library.pdx.edu/open_access_etds/3486.

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The Chehalis River Basin is located in the southwest region of Washington State, originating in the Olympic Mountains and flowing to Grays Harbor and the Pacific Ocean. The Chehalis River is over 125 miles, exists within five counties, and flows through agricultural, residential, industrial, and forest land areas. Four major rivers discharge to the Chehalis River, as well as many smaller creeks, five wastewater treatment plants, and groundwater flows. Flooding is a major problem in the relatively flat areas surrounding the cities of Chehalis and Centralia, with severe consequences for property, safety and transportation. As a result, construction of a flood-control dam in the upper basin has been proposed. One major concern of constructing a dam is the potentially severe impacts to fish health and habitat. The Chehalis River has routinely violated water quality standards for primarily temperature and dissolved oxygen, and has had multiple water quality and Total Maximum Daily Load studies beginning in 1990. CE-QUAL-W2, a two-dimensional (longitudinal and vertical) hydrodynamic and water quality model, was used to simulate the Chehalis River, including free flowing river stretches and stratified (in summer) lake-like stretches. The goals of this research were to assess the flood retention structure's impacts to water quality, as well as river responses to potential climate change scenarios. In order to use the model to achieve these goals, calibration to field data for flow, temperature, and water quality constituents was performed. This involved developing meteorological data, riparian shading data, and flow, temperature, water quality records for all tributaries during the calibration period of January 1, 2013 to December 31, 2014. System cross-sectional geometry data were also required for the model grid. Because of the short travel time in the river, the model was sensitive to boundary condition data, wind speed, bathymetry, nutrient kinetics, and algae, epiphyton, and zooplankton kinetics. Future conditions showed predictions of warmer water temperatures and slight changes to water quality conditions on the river. As fish in the area prefer cooler water temperatures, this could pose a threat to fish health and habitat. Flood retention structures also showed impacts to river temperature and water quality. Structures with the purpose of flood retention only (only operating during times of flooding) gave model predictions for daily maximum temperature higher than structures that employed flood retention and flow augmentation (operating during all times of the year). This suggested the management of flow passage or retention by the dam is important for water quality on the river. As this research continues improvements will be made, particularly to temperature and water quality constituents. Additional data for the system would be beneficial to this process. Model predictions of temperature were sensitive to meteorological data, including cloud cover, which were largely estimated based on solar radiation. Additional meteorological data throughout the basin would be useful to temperature results. Temperature results were also sensitive to the model bathymetry, and additional investigations into segments widths and water depths may improve temperature predictions. Water quality constituent data were largely lacking for the system. Many estimation techniques and approximations were used for input water quality constituents for the model upstream boundary and tributaries when little or no data were available, introducing uncertainty to the model. It was not possible to calibrate pH to field data because alkalinity data were essentially unavailable. However, other constituents had good agreement between model predictions and field data, including dissolved oxygen, nitrates, total phosphorus, and total suspended solids.

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Park, Kyeong. "A model study of hydrodynamic and water quality characteristics of the Rappahannock Estuary, Virginia." W&M ScholarWorks, 1993. https://scholarworks.wm.edu/etd/1539616803.

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A laterally integrated, two-dimensional, real-time model, consisting of linked hydrodynamic and water quality models, is developed and applied to the Rappahannock Estuary, Virginia. The hydrodynamic model, based on the principles of conservation of volume, momentum and mass, predicts surface elevation, current velocity and salinity. The water quality model, based on the conservation of mass alone, predicts eight parameters; dissolved oxygen (DO), chlorophyll 'a', carbonaceous biochemical oxygen demand (CBOD), organic nitrogen, ammonia nitrogen, nitrite-nitrate nitrogen, organic phosphorus and inorganic phosphorus. The model equations were solved using a two time level, finite difference scheme. The hydrodynamic model was calibrated and verified using field data collected in 1987 and 1990, and was used to study hydrodynamic processes. A reverse longitudinal salinity gradient, that has been frequently observed in the Rappahannock, was explained in terms of bottom topography and vertical mixing. This argument was further supported by the salinity data from 1981-1990 slackwater surveys. The often confusing usage of the phrase "limit of salt intrusion" in place of "limit of gravitational circulation" was clarified. The water quality model was calibrated and verified using the field data from 1990 surveys, and was used to study water quality conditions. Hypoxia, even anoxia, persists during summer in the bottom water of the lower portion of the Rappahannock. Sensitivity analysis showed that the bottom water ends up being hypoxic regardless of DO and CBOD in the incoming bay water, and hypoxia can be relieved more by eliminating CBOD than by increasing DO in the incoming bay water. An increase in either residual velocity or vertical mixing can relieve the hypoxic condition. Water column respiration, including CBOD decay, nitrification and algal respiration, is as important as sediment oxygen demand, and the CBOD decay is the most important in the water column. High chlorophyll concentrations in the lower portion of tidal freshwater have been observed frequently in many estuaries. Sensitivity analysis indicated that the high chlorophyll in the Rappahannock cannot be maintained without an external input of nutrients. A hypothesis was proposed to account for the nutrient source and the downriver limit of high chlorophyll concentrations.

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Hammond, Andrew Jesse. "Hydrodynamic and Water Quality Simulation of Fecal Coliforms in the Lower Appomattox River, Virginia." Thesis, Virginia Tech, 2004. http://hdl.handle.net/10919/10126.

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The Virginia Department of Environmental Quality (VADEQ) under the direction of the United States Environmental Protection Agency (USEPA) has listed the lower Appomattox River as impaired because it violates current water quality standards for fecal coliforms. To advance the analytical process by which various scenarios for improving water quality within the estuary are examined, an array of computer-based hydrodynamic and water quality models were investigated. The Dynamic Estuary Model (DYNHYD5), developed by USEPA, was used to simulate hydrodynamics within the lower Appomattox River. The Water Quality Analysis Simulation Program (WASP6.1), also developed by USEPA, was employed to perform water quality simulations of fecal coliforms. Also, a detailed literature review examined DYNHYD5 and WASP6.1 model theory, computer-based model solution techniques, and background hydrodynamic theory. DYNHYD5 sensitivity analysis showed that the model was most responsive to tidal heights (seaward boundary conditions) both upstream and downstream within the model network. Specific model parameters were varied during calibration until modeled water surface elevations converged on observed water surface elevations. A goodness-of-fit value of 0.749 was determined with linear regression analysis for model calibration. DYNHYD5 input parameter validation was performed with additional observations and a goodness-of-fit value of 0.829 was calculated. Through sensitivity analysis, WASP6.1 proved to be most responsive to coliform loading rates in the downstream direction and boundary concentrations in the upstream direction. With these results, WASP6.1 input parameters were calibrated against observed fecal coliform concentrations. A goodness-of-fit value of 0.573 was determined with linear regression analysis for model calibration. WASP6.1 input parameter validation was performed with additional observations and a goodness-of-fit value of 0.0002 was calculated. Model results suggest that hydrodynamic model calibration and validation can be improved with additional tidal height observations at the downstream seaward boundary. Similarly, water quality model calibration and validation can possibly be improved with the aid of detailed, time-variable coliform concentrations at the downstream seaward boundary. Therefore, it is recommended that a water quality sampling station and tidal stage recorder be installed at the confluence of the Appomattox and James Rivers to provide for further testing of estuary hydrodynamic and water quality models.
Master of Science

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15

Heller, Winfried. "Hydro-dynamic effects with particular consideration of water quality and their measurement methods." Doctoral thesis, Tönning; Lübeck; Marburg : Der Andere Verl, 2005. http://deposit.ddb.de/cgi-bin/dokserv?idn=979397405.

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16

John, V. Chandy. "Development and application of linked hydrodynamic-water quality models for small lakes, reservoirs, and tidal inlets." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ31528.pdf.

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Obregon, Oliver. "Evaluating Climate Change Effects in Two Contrasting Reservoirs Using Two-Dimensional Water Quality and Hydrodynamic Models." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3094.

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I analyzed and compared impacts from global climate change (GCC) and land use change to Deer Creek (United States) a temperate reservoir and Aguamilpa (Mexico), a tropical reservoir by using calibrated CE-QUAL-W2 (W2) water quality and hydrodynamic models based on field data over an extended time period. I evaluated and compared the sensitivity to predicted GCC and land use changes. I individually evaluated changes to air temperature (TAIR), inflow rates (Q), and nutrient loads (PO4-P and NO3-NO2-N) followed by analysis of worst case scenarios. I developed analysis methods using indexes to represent the total reservoir change calculated using the total parameter mass (i.e., algae, dissolved oxygen, total dissolved solids) normalized by the reservoir volume to eliminate apparent mass changes due to volume changes. These indexes have units of average concentrations, but are better thought of as a global reservoir index or normalized concentration. These indexes allow analysis of the total reservoir and not just specific zones. Total normalized algal concentrations were impacted more by changes in nutrient inflows (land use) in both reservoirs than to changes in TAIR and Q. For Deer Creek, PO4-P changes significantly increased normalized algal concentrations in the reservoir and in dam releases when PO4-P inflow was increased by 50%. Aguamilpa was more sensitive to NO3-NO2-N changes, exhibiting significant increases in normalized algal concentration for the +50% NO3-NO2-N simulation. Both reservoirs showed small changes to normalized algal concentration for the +3ºC TAIR simulation with the largest changes occurring during warm seasons. However, Deer Creek exhibited decreased total algal levels when TAIR was increased by 3ºC while Aguamilpa showed increased total algal levels with the 3ºC increase in TAIR. These contrasting trends, a decrease in Deer Creek and an increase in Aguamilpa, were produced by algae succession processes. Changes in Q affected normalized algal concentration in both reservoirs in different ways. In Aguamilpa, total algal levels increased under dry conditions while Deer Creek showed little general change associated with flow changes. Worst case scenario simulations, which included changing more than one parameter, showed that GCC changes can cause large impacts if they occur simultaneously with high nutrient loadings. These results begin to show how GCC could impact reservoirs and how these impacts compare to potential impacts from land use change. The results show that both temperate and tropical reservoirs are impacted by GCC but are more sensitive to nutrients. The methods, plots, and tools developed in this study can assist water managers in evaluating and studying GCC and land use changes effects in reservoirs worldwide.

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McCulloch, Andrew John. "Developing and Calibrating the Hydrodynamic and Water Quality Model CE-QUAL-W2 for Banks Lake Washington." PDXScholar, 2011. https://pdxscholar.library.pdx.edu/open_access_etds/180.

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Located in central Washington State, Banks Lake serves as an irrigation storage reservoir for the Columbia Basin Irrigation Project and is home to a diverse fisheries population. The current hydrologic management strategies used for Banks Lake have been chosen to serve two purposes: to adequately store and provide irrigation water for the Columbia Basin Irrigation Project and to maintain a healthy aquatic environment suitable for the growth and habitation of local flora and fauna. Increased needs for irrigation water within arid central Washington poses additional challenges to reservoir managers so that irrigation needs are met without damaging the present aquatic environment within Banks Lake. Future plans by the Washington Department of Ecology to use Banks Lake storage to replenish ground water reserves of the Odessa Subarea aquifer have required an investigation into how increased seasonal drawdown may affect fish growth, fish habitat and overall limnology of Banks Lake. The goal of this project is to produce a hydrodynamic and water quality model of Banks Lake that can predict the impacts of management strategies on the lake's water quality and the linkage of lake management to fish habitat.

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Al, Murib Muhanned. "Hydrodynamic and Water Quality Modeling of the Tigris River System in Iraq Using CE-QUAL-W2." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4230.

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The Tigris River is one of two primary rivers in Iraq and is, along with the Euphrates, the main source for drinking and irrigation water in the country. The Tigris River originates in the Taurus Mountains in Turkey, and is 1850 km long. The majority of the river lies within Iraq. The river passes through, and is the primary drinking water source for major cities such as Mosul, Baeji, Samarra, Baghdad (the capital), and Kut. The Tigris River joins the Euphrates River in Qurna city within Basra province to form the Shatt Al-Arab River which eventually discharges into the Persian Gulf. As a result of fluctuations in flow rate along the Tigris River that cause both potential flooding and drought, Mosul Dam was built on the mainstem of the Tigris River upstream of the city of Mosul and was operated starting in July 1986 to control the river flow and to generate hydroelectricity. Some canals were also constructed to divert excess fresh water from the mainstem of the river at Samarra Barrage located 125 km north (upstream) of Baghdad to Tharthar Lake, an artificial lake located 100 km northwest Baghdad city. The Tigris-Tharthar canal, 75 km long, was constructed in 1956 to divert excess water from Samarra Barrage to Tharthar Lake and to prevent potential flooding in Baghdad. During dry seasons, high total dissolved solids (TDS) water is diverted from Tharthar Lake into the mainstem of the Tigris River through the 65 km long Tharthar-Tigris canal, which is located 25 km upstream Baghdad. Due to rapid population growth and increasing industrial activates, the Tigris River is also facing many water quality challenges from inflows of contaminated wastewater from treatment plant stations. A water quality model that simulates the Tigris River system is therefore needed to study the effects of these discharges and how water quality of the Tigris River could be managed. To address this issue, CE-QUAL-W2 was used to develop a 2-D (longitudinal and vertical) hydrodynamic and water quality model of the mainstem Tigris River from Mosul Dam (Rkm 0) to Kut Barrage (Rkm 880). In addition, Tharthar Lake and its canals were modeled. A full suite of hydrodynamic and water quality variables were simulated for the year 2009, including flowrates, water level, and water temperature. Additionally, water quality constituents such as total dissolved solids (TDS), phosphate (PO4), ammonium (NH4), nitrate (NO3), biochemical oxygen demand (BOD), chlorophyll-a (Chl-a), and dissolved oxygen (DO) were also simulated. Bathymetry of the Tigris River and field data such as flowrate, water level, TDS, NO3 were obtained from the Ministry of Water Resources in Iraq, while surface water temperatures of the Tigris River were estimated remotely using Landsat satellites. These satellites provided a continuous observation record of remote sites. Other water quality field data, such as PO4, NH4, BOD, and DO, were estimated from literature values. Meteorological data, including, wind speed, wind direction, air and dew point temperatures, cloud cover, and solar radiation were obtained from the Iraqi Ministry of Transportation, the General Organization for Meteorology and Seismic Monitoring. Model predictions of flow and water level were compared to field data at three stations along the mainstem of the Tigris River, including Baeji, downstream of Samarra Barrage, and Baghdad. The absolute mean error in the flow varied from 12.6 to 3.4 m3/s and the water level absolute mean error varied from 0.036 to 0.018 m. The percentage error of the overall flowrate at Baeji, downstream Samarra Barrage and Baghdad was 1.9%, 0.8%, and 0.8% respectively. Injecting a conservative tracer at Mosul Dam showed that a parcel of water reaches to Baeji, Samarra Barrage, Baghdad, and Kut Barrage after approximately 3 days, 5 days, 10 days, and 19 days, respectively. Water temperature field data in Iraq are limited and there was no archive of existing field data. Therefore, I obtained estimates of surface water temperature on the Tigris River using the thermal band of the Landsat satellite, one of a series of satellites launched by the National Aeronautics and Space Administration (NASA). The calibration between satellite data and water temperature was validated using sparse field data from 2004, and the calibration then applied to 82 Landsat images from the year 2009. Landsat estimates showed a bias of -2°C compared to model results in winter months, possibly due to uncertainty in Landsat estimations. The absolute mean errors of the CE-QUAL-W2 model predictions of water temperature compared to Landsat estimated temperatures were 0.9 and 1.0°C at Baeji and Baghdad respectively. Temperature calibration in the Tigris River system was highly sensitive to meteorological input data. Landsat Images were also used to estimate longitudinal variation in surface water temperature of Tharthar Lake. It was found that surface water temperature in Tharthar Lake varied longitudinally along the North-South axis with warmer temperatures in the lower part compared with the upper part of the lake. Total dissolved solids concentrations in the Tigris River significantly increased from Mosul Dam to Kut Barrage with peak concentrations of 900 mg/l and 1050 mg/l at Baghdad and Kut, respectively, due to high TDS water diverted from Tharthar Lake, irrigation return flow, urban runoff, and uncontrolled discharge of wastewater effluents. NO3 concentrations did not significantly increase between Samarra Barrage and Baghdad city. BOD concentrations within Baghdad were extremely high due to direct discharge of industrial wastewater into the mainstem of the Tigris River from outlets located within the city. Management scenarios were simulated with the model of the Tigris River system and were compared with the base model. The main scenarios implemented on the Tigris River system were altering upstream hydrology, increasing air temperature due to the effect of climate change, disconnecting Tharthar Lake from the Tigris River system, and simulating long-term effects on Tharthar Lake. Increasing upstream inflows caused a decrease in TDS concentrations from 495 mg/l to 470 mg/l over all the mainstem of the river. In addition, CBOD concentrations decreased somewhat from 5.9 mg/l to 5.74 mg/l. On the other hand, decreasing upstream flows caused a significant increase in average TDS concentrations over the entire Tigris mainstem from 495 mg/l to 527 mg/l. Also, an increase in CBOD concentrations from 5.9 mg/l to 6.2 mg/l was predicted over all the mainstem of the river. Implementing the climate change scenario on the base model of the Tigris River system showed a 5% increase in annually averaged water temperature from 20.7°C to 21.68°C over the mainstem river. Climate change scenarios produced no significant impacts on TDS and CBOD concentrations in the mainstem, while DO concentrations decreased from 8.15 mg/l to 7.98 mg/l with a slight increase in Chl-a concentration from 1.97 µg/l to 2 µg/l in the mainstem. Disconnecting Tharthar Lake from the system showed a remarkable 25% decrease in TDS concentrations, with an average concentration changed from 495 mg/l to 397 mg/l in the mainstem due to an extra 36% increase in flow discharged downstream of Samarra Barrage. Also, Chl-a concentration significantly decreased by 40% with an average concentration changed from 2 µg/l to 1.2 µg/l. Additionally, a 6-year model simulation of the Tigris River system was performed to evaluate the long-term effects on Tharthar Lake. No significant impact was observed in the average temperature of the lake. TDS concentrations in the lake decreased from 1239 mg/l to 1041 mg/l. PO4, NH4 and NO3 concentrations decreased by 2%, 66% and 26%, respectively. Chl-a concentration in Tharthar Lake decreased from 2.0 µg/l to 1.61 µg/l. After decreasing BOD concentrations of the Tigris River by 50%, BOD concentrations in the mainstem decreased by 24%, while DO concentrations increased by 2.8%. There were no significant impacts on Chl-a concentrations in the mainstem of the river. Finally, for a scenario where extremely low dissolved oxygen release from Mosul Dam in the summer, it was found that approximately 50 km below Mosul Dam was affected before DO concentrations reached an equilibrium concentration. For further work on the Tigris River system, it is recommended to model the Tigris River from Kut Barrage to the confluence with the Euphrates River, about 400 km long, and connect it with the current model to have a complete model of the Tigris River system from Mosul Dam to the confluence with the Euphrates River. This is necessary to manage water the entire system of the Tigris River and also to provide enough water with good quality in Basra.

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Yan, Yinzhou. "High-quality laser machining of alumina ceramics." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/highquality-laser-machining-of-alumina-ceramics(3dd60fb6-5bda-4cc9-8f00-f49b170ca6aa).html.

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Alumina is one of the most commonly used engineering ceramics for a variety of applications ranging from microelectronics to prosthetics due to its desirable properties. Unfortunately, conventional machining techniques generally lead to fracture, tool failure, low surface integrity, high energy consumption, low material removal rate, and high tool wear during machining due to high hardness and brittleness of the ceramic material. Laser machining offers an alternative for rapid processing of brittle and hard engineering ceramics. However, the material properties, especially the high thermal expansion coefficient and low thermal conductivity, may cause ceramic fracture due to thermal damage. Striation formation is another defect in laser cutting. These drawbacks limit advanced ceramics in engineering applications. In this work, various lasers and machining techniques are investigated to explore the feasibility of high-quality laser machining different thicknesses of alumina. The main contributions include: (i) Fibre laser crack-free cutting of thick-section alumina (up to 6-mm-thickness). A three-dimensional numerical model considering the material removal was developed to study the effects of process parameters on temperature, thermal-stress distribution, fracture initiation and propagation in laser cutting. A rapid parameters optimisation procedure for crack-free cutting of thick-section ceramics was proposed. (ii) Low power CW CO2 laser underwater machining of closed cavities (up to 2-mm depth) in alumina was demonstrated with high-quality in terms of surface finish and integrity. A three-dimensional thermal-stress model and a two-dimensional fluid smooth particle hydrodynamic model (SPH) were developed to investigate the physical processes during CO2 laser underwater machining. SPH modelling has been applied for the first time to studying laser processing of ceramics. (iii) Striation-free cutting of alumina sheets (1-mm thickness) is realised using a nano-second pulsed DPSS Nd: YAG laser, which demonstrates the capability of high average power short pulsed lasers in high-quality macro-machining. A mechanism of pulsed laser striation-free cutting was also proposed. The present work opens up new opportunities for applying lasers for high-quality machining of engineering ceramics.

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Al-Zubaidi, Hussein Ali Mahdi. "3D Hydrodynamic, Temperature, and Water Quality Numerical Model for Surface Waterbodies: Development, Verification, and Field Case Studies." PDXScholar, 2018. https://pdxscholar.library.pdx.edu/open_access_etds/4500.

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Numerical modeling has become a major tool for managing water quality in surface waterbodies such as rivers, lakes, reservoirs, and estuaries. Since the two-dimensional longitudinal/vertical model CE-QUAL-W2 is a well-known model and it has been applied to thousands of waterbodies around the world successfully, its numerical scheme was adapted to develop a new three-dimensional numerical model for simulating hydrodynamics, temperature, and water quality in surface waterbodies. Finite difference approximations were used to solve the fluid dynamic governing equations of continuity, free water surface, momentums, and mass transport. No coordinate transformations were performed and the z-coordinate system has been used. Higher-order schemes (QUICK, QUICKEST, and ULTIMATE QUICKEST) in addition to the UPWIND scheme were used for the advective temperature and mass transport. A novel numerical approach was used for the numerical formulation of the three-dimensional scheme. This approach forced the numerical solution of the free surface equation to be a tri-diagonal matrix form rather than a more computationally intensive penta-diagonal matrix solution. This new approach was done by linking a method called line-by-line with the free water surface numerical solution. Another new approach was that the three-dimensional numerical scheme involved a simultaneous solution of hydrodynamics, temperature, and water quality at every model time level instead of saving the hydrodynamic results to be used later for water quality simulation. Hence, this scheme allowed feedback between the hydrodynamics and water quality every time step. In addition, various unique numerical algorithms were employed from CE-QUAL-W2 such as the W2 turbulence model, selective withdrawal theory, surface heat fluxes, and water quality sources and sinks, making the three-dimensional model built on well-tested algorithms. To test the model structure and assumptions, an analytical verification was performed by comparing model predictions to known analytical exact solutions test cases. Good agreement was showed by the model for all of these tests. A computation of the volume balance over the simulation period was also incorporated within the model to assess how well the code performed. Sensitivity tests were also made varying bed and wind shear. The model was also applied to three reservoirs in the USA as field case studies: Lake Chaplain in WA, Laurance Lake in OR, and Cooper Creek Reservoir in OR. The model was validated by comparing the model predictions of water levels, velocities, vertical temperature profiles, and dissolved oxygen with field data. Through these real applications, the numerical predictions of the 3D model showed good agreement with field data based on error statistics. The model results of each field case study were discussed separately. In the Lake Chaplain model application, the study was focused on the importance of the higher-order schemes compared to the first-order UPWIND scheme. The model predictions of temperature were determined by using the UPWIND, QUICK, and QUICKEST scheme and compared with field data. The Error statistics of the model predictions compared to field data were an absolute mean error (AME) of 0.065 m for the water level predictions and an overall AME of 1.62 °C, 1.09 °C, and 1.23 °C for the temperature predictions by using the UPWIND, QUICK, and QUICKEST scheme, respectively. In the Laurance Lake model application, a comparison was performed between the present 3D model and the 2D CE-QUAL-W2. Since the 3D model was build based on CE-QUAL-W2, differences between the two models were evaluated. Error statistics between the model predictions of water level and temperature compared to field data showed that both models were in good agreement with field data. However, the 3D model AME (0.30 m for the water level predictions and 0.48 °C for the temperature predictions) was higher than the 2D model (0.03 m for the water level predictions and 0.42 °C for the temperature predictions). Finally, the Cooper Creek Reservoir case study was done to show the model predictions of temperature and dissolved oxygen. In this application, vertical temperature profiles were covered the entire simulation period in order to show how the model transfer heat between stratification and non- stratification conditions. The model showed good agreement with field data (0.12 m AME for the water level predictions, 1.00 °C overall AME for the temperature predictions, and 1.32 g/m3 overall AME for the dissolved oxygen predictions). Finally, comparisons were made between CE-QUAL-W2 and the 3D model. The 2D model generally performed better in the tests cases if the model user is unconcerned about lateral impacts. The 3D model is important to use when lateral currents and variation in the lateral dimension are important.

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Visser, Alwyn Jacobus Christiaan. "Real-time management of river systems by using a hydrodynamic model with optimisation." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5438.

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Thesis (MScEng (Civil Engineering))--University of Stellenbosch, 2010.
ENGLISH ABSTRACT: In this research a Real-Time hydrodynamic optimisation model of the Orange-Fish-Sundays River (OFS) system which uses real-time data in order to forecast release hydrographs, is evaluated. The OFS system stretches over three catchment areas in the Eastern Cape namely Great Fish, Little Fish and Sundays Rivers. The OFS supplies water from the Orange River through a 800 km system of canals, tunnels, dams and rivers to registered water users in this area. In order to cope with increasing pressures on water saving, water demand, water quality and dam safety, the Department of Water Affairs implemented this Orange Fish Sundays-Real Time (OFS-RT) system to calculate the optimal water flow, by running customised Danish Hydraulic Institute (DHI) MIKE11 software. The system utilizes an optimisation module that evaluates the simulated outcome at seven water release structures (dams, weirs and tunnels). Then during the optimisation process performs more adjustments to reach the objectives of the system to obtain the forecast release hydrographs. This OFS-RT model aims at target based objectives, using: (i) Hydras real-time field data of dam water levels, river flows and water quality from the area sent to the control office main computer at four hourly intervals via SMS and (ii) abstractors weekly water requests. This system takes irrigation and domestic demand into account as well as water quality, evaporation, rainfall, dam levels, dam safety, instream flow requirements and tributary flow. In order to manage the water flows through the OFS system the OFS-RT model forecasts the release hydrographs and uploads the predictions to a website to smooth operational procedures. The target outcomes were tested and evaluated during this research and it was found that the OFS- RT model succeeded in delivering release forecasts for the seven control structures to manage the OFS system. This research proved that management of river systems by using a real-time hydrodynamic model with optimisation is a useful tool for the optimal utilisation of water resources.
AFRIKAANSE OPSOMMING: Die doel van hierdie navoring is die evaluering van „n intydse hidrodinamiese optimiseringsmodel van die Oranje-Vis-Sondagsrivier (OVS) stelsel wat intydse data ontvang en loslatings hidrograwe verskaf. Die OVS stelsel strek oor drie opvangsgebiede in die Oos-Kaap: naamlik die Groot Vis-, Klein Vis- en Sondagsriviere en voorsien water vanuit die Oranjerivier deur „n 800 km stelsel van kanale, tonnels, damme en riviere, aan geregistreerde waterverbruikers in die gebied. Ten einde te voldoen aan die eise van waterbesparings, stygende vraag na water, die verskaffing van goeie water gehalte en damveiligheid, het die Departement van Waterwese „n intydse rekenaar model (OVS-IT) geïmplimenteer om die optimale watervloei deur middel van die aangepaste MIKE11 sagteware van die Danish Hydraulic Institute (DHI) te bereken. Hierdie stelsel maak gebruik van „n optimisering module wat die gesimuleerde uitkomste van verstellings aan sewe waterloslatingstrukture evalueer. Met optimisering word die verlangde hidrograaf deur verder aanpassings verkry. Data wat nodig is om die OVS-IT model se doel te bereik is: (i) Hydras intydse velddata van damwatervlakke, riviervloeie en water gehalte van die gebied ontvang deur die beheerkantoor se hoofrekenaar via SMS elke vier ure, en (ii) water verbruikers se weeklikse wateraanvrae Die stelsel neem die besproeiing en huishoudelike aanvraag in ag, sowel as soutgehalte, verdamping, reënval, damvlakke, dam veiligheid, stroom vloei vereistes en sytak byvloei. Die OVS se watervloei word beheer deur voorspelde loslatings hidrograwe, opgesom op „n webwerf wat die uitvoer prosedures aandui. Die intydse hidrodinamiese model met optimisering het volgens hierdie navorsing daarin geslaag om vir die beheer van die OVS stelsel, die loslatings van sewe beheerstrukture akkuraat te voorspel en bevind dat die model „n waardevolle instrument is vir die optimale bestuur van waterhulpbronne.

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Xu, Wenwei. "Development of a Steady-State River Hydrodynamic and Temperature Model Based on CE-QUAL-W2." PDXScholar, 2014. https://pdxscholar.library.pdx.edu/open_access_etds/1619.

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CE-QUAL-W2 is a 2-D hydrodynamic and water quality model that has been applied to reservoirs, lakes, river systems, and estuaries throughout the world. However, when this model is applied for shallow systems, this model requires a long calculation time to maintain numerical stability, compared to applications of reservoirs or deeper river systems. To solve this problem, a new hydrodynamic and temperature model was built based on the framework of CE-QUAL-W2 but that allows for steady-state hydrodynamic computations. By calculating the hydrodynamics at steady-state, the time step for stability is relaxed and simulations can proceed at much higher time steps. The rest of the model framework is still used for water quality state variables, in this case, temperature. The algorithm used for computing the water surface elevation is Manning's equation. This thesis study is one part of the Willamette Water 2100 project (Santelmann et al., 2012), which examines hydrological, ecological, and human factors affecting water scarcity in the Willamette River Basin. This study included three stages: (1) Convert six existing CE-QUAL-W2 V3.1 models into a newer version: CE-QUAL-W2 V3.7. (2) Develop the steady-state model code in FORTRAN. (3) Test the steady-state model on three river systems in the Willamette River Basin at Year 2001 and 2002. The result proved that the steady-state model could reduce the computing time by 90% for river applications, while predicting dynamic river temperature with high accuracy at a two-minute time scale. This new model will be employed to simulate the future of the Willamette River System at a decadal or centennial timescales, addressing river temperature concerns and fish habitat issues.

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24

Huber, Anita. "Internal mixing in a mine lake /." Connect to this title, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0103.

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25

LI, ZHIWEI. "NETWORK WATER QUALITY MODELING WITH STOCHASTIC WATER DEMANDS AND MASS DISPERSION." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1147989825.

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26

Huber, Anita. "Internal mixing in a mine lake." University of Western Australia. School of Environmental Systems Engineering, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0103.

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[Truncated abstract] Mine lakes are a water body created after an open-cut mine ceases operating. The lakes develop in the former mine-pit due to the combination of groundwater inflow, surface run-off and, in some cases, due to rapid filling from river diversion. While potentially valuable water resources, these lakes often have poor water quality and managing the water body is an important part of the overall process of mine site rehabilitation. As mine lakes form in man-made pits, they have a bathymetry that is typically quite distinct from natural lakes and this can, in turn, strongly influence the hydrodynamics and hence the water quality of the water body. Despite the potential importance of these water bodies, there have been very few studies on the hydrodynamics of mine lakes. This study describes a field investigation of the hydrodynamics of a former coal mine lake, Lake Kepwari, in south-western Western Australia. In particular, this study examines the hydrodynamic processes in both the surface mixing layers and the internal mixing in the density stratified lake. Wind sheltering in the surface mixing layer occurs due to the presence of the steep walls and lake embankments. A week long field experiment was conducted in December 2003 using a combination of moored thermistor chains with meteorological stations and the deployment of rapid vertical profiling turbulent microstructure instruments and CTD drops from two boats operating on the lake. ... Simulations indicated that inclusion of a site specific sheltering effect, based on the results of the field campaign, significantly improved the models‘ performance in capturing the surface mixed layer deepening associated with episodic strong wind events that occur on the lake. Considerable internal mixing was indicated by the high dissipation rates observed, particularly near the boundaries. Large basin-wide diffusivities were also calculated from the heat budget method over long periods, showed a consistency with time, and were slightly higher in summer than during the Autumn Winter period. Although light, there are persistent winds over the lake and yet little basin-scale internal wave activity or seiching. It is hypothesized that any seiching motion was rapidly damped by strong mixing over the hydraulically rough bathymetry bathymetry created by the remnant benches from the open cut mining operation itself. This boundary mixing, in turn, drives secondary relaxation currents that transport mixed fluid from the boundaries to the interior, resulting in high effective basin-wide diffusivities. A simple boundary mixing model is proposed to describe this process.

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27

Virtanen, M. (Markku). "Mathematical modelling of flow and transport as link to impacts in multidiscipline environments." Doctoral thesis, University of Oulu, 2009. http://urn.fi/urn:isbn:9789514292002.

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Abstract Examples of numerical modelling of surface water hydrodynamics and water quality are presented. Their meaning for the development of the EIA 3D model system is analyzed from the almost 70 tracer studies (mainly 1971–1974) until the 3-dimensional (3D) solutions which became dominant since 1982. Up to summer 2008, the number of 3D applications has increased to almost 230 while the number of all applications exceeds 300. The specific applications considered are from: Porttipahta reservoir in Northern Finland (I), Porttipahta and Lokka reservoirs (II), combination of reservoirs, lake, river sections, Kemi estuary and the sea (III), Kemi estuary and other coastal applications in the Gulf of Bothnia (IV), Lake Haukivesi in Eastern Finland (V), Lake Näsiselkä in South-West Central Finland (VI), and Kymi River and Kotka estuary in Southern Finland (VII). A detailed description of the 3D model system is given in the application of Näsiselkä (VI). It is completed with drastically changing water levels, drying and wetting of immersed areas, characteristics of pulsing system, and internal loading in the application of Porttipahta (I). The application of the Kymi River and Kotka estuary (VII) shows the sensitivity of tracers as transport indicators and the validity of the transport model. In Lokka and Porttipahta (II) the methods of validity tests are extended to include field tests, laboratory experiments, and comparisons with expert evaluations and analytical solutions. A strong indication of model validity is obtained in Näsiselkä (VI). When the loading after the model work was changed according to a plan included in the computation, the observed changes of water quality corresponded closely with those predicted by the model. Another severe indication of the model validity is from Porttipahta and Lokka (I, II). With the parameter values based on data from 1967–1986, a recent application indicated a close agreement with the observed data from 2000–2006. In Haukivesi (V) and Näsiselkä (VI) the agreement between the model and observed results is extended to the biological indicators of the algal biomass. The integrated application to the network of a planned and two existing reservoirs, a strongly regulated lake, river sections, Kemi estuary and the sea (III) shows the usability of the model system to all types of water bodies. As a practical result it highlights the decay of the effects of a new impoundment with time and distance, including fast dilution in the estuary and the sea.

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Lefebvre, Karine. "Diagnostic et quantification des flux nappe - rivière : modélisations hydrodynamique et géochimique du bassin versant de l'Yvette amont (France)." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS152/document.

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Dans le contexte péri-urbain à dominance agricole de l’Ile de France, les pressions anthropiques exercées sur les rivières jouent autant sur la qualité que sur le débit des cours d'eau. Située au sud-ouest de Paris, l’Yvette draine un bassin versant de 202 km²et à la géologie homogène. Elle est alimentée directement par des stations d'épuration (STEP) et par la nappe des sables de Fontainebleau qui représente la principale source d’eau. Sur ce type de bassin, la gestion durable du système riverain repose sur la connaissance de la distribution des flux nappe – rivière et sur l’impact de cette répartition sur la qualité des cours d’eau.La dynamique des flux d’eau a été suivie grâce à l’implantation de stations hydrométriques aux points clés du réseau hydrographique (i.e. exutoires des principaux affluents, aval des confluences sur l’Yvette). Les flux chimiques ont été étudiés par analyses d’échantillons d’eau recueillis lors de campagnes de terrain effectuées en période d’étiage sur les cours d’eau. Un modèle conceptuel global, calibré à partir des chroniques de débit, a permis (i) d’estimer des variations spatiales de la recharge de la nappe (60 – 160 mm.an-1), et (ii) d’établir une répartition journalière des parts d’eau de nappe, de STEP et de ruissellement en rivière, pour la période 2001-2014. Par ailleurs, l’analyse des traceurs géochimiques (e.g. Cl-, NO3-, SO42-) et isotopiques (222Rn, δ18Oeau, δ2Heau) soutient la prédominance, aussi bien quantitative que qualitative, de la nappe sur les rivières.D’un point de vue hydrodynamique, le contexte géomorphologique homogène procure aux rivières une dynamique similaire avec des épisodes de crues très courts (de l’ordre de quelques heures) et des périodes d’étiages marqués, quelle que soit la saison. L’étude par sous-bassin a mis à jour une différence entre les bassins topographiques et les bassins d’écoulement souterrains, créant des déficits hydriques sur l’amont de certains cours d’eau (e.g. Mérantaise, Ru des Vaux) au profit d’autres (e.g. Rhodon). Le parallèle entre bassins topographique et souterrain n’a pu se faire qu’au niveau du cours principal de l’Yvette. Sur la période 2001-2014, le débit de l’Yvette provient en moyenne à 55 % de la nappe, à 38 % du ruissellement et à 8 % des STEP. En période de basses eaux, la contribution des STEP reste sensiblement identique tandis que la nappe constitue la principale alimentation des rivières (90 %), contrôlant donc leur qualité. Mais la composition chimique de ce soutien souterrain n’est pas homogène. Pour déterminer l’origine de ces disparités, un travail à plus petite échelle a été conduit sur un affluent majeur de l’Yvette (le Rhodon). La décharge de la nappe en rivière y est bimodale : 15 % arrive par voie souterraine et 85 % transite par les milieux humides en surface. Au sein des zones humides sont observées de fortes hétérogénéités dans les écoulements et leur chimie, avec des flux de subsurface totalement épurés en nitrates et du ruissellement riche en nutriments. La prédominance de des flux de surface réduit fortement le pouvoir épurateur des milieux humides, avec seulement 6 % des eaux de nappe épurées avant leur décharge en rivière. Cette faible efficacité renforce l’impact direct de la qualité de la nappe sur les rivières. Sur le bassin, la nappe est stratifiée par l’intervention de nombreux processus de recharge (infiltrations d’eau d’étang, de STEP, de zones humides de plateau). Les petits sous-bassins (< 50 km²) semblent dominés par cette stratification, ainsi que par les apports de STEP qui contribuent aux flux chimiques des rivières à hauteur de 30 à 50 %. Le cours principal de l’Yvette, dans sa partie aval, dépend des mélanges issus des confluences avec ses affluents. Les outils utilisés ici ont donc mis en avant les différences de fonctionnement des bassins selon l’échelle concernée, tout en reliant l’importance de la compréhension du système à petite échelle pour la gestion à grande échelle
In the peri-urban context with large farm practices of the Paris region, anthropogenic pressures on streams and rivers impact both their flow and quality. Located in the southwestern of Paris, the Yvette stream drains a watershed of 202 km², in a homogeneous geological context. The stream is sustained by waste water treatment plant (WWTP) and by the Fontainebleau sands aquifer which represents the main source of water.In this context, the sustainable management of the stream and its riparian zones needs the assessment of groundwater discharge locations and chemistry, and their impact on the stream water quality.Water fluxes in the stream and in its main tributaries have been recorded at 11 stations. Dissolved elements distributions have been studied by field works in low-flows conditions. A lumped model, calibrated with stream flow hydrographs, has allowed (i) the estimation of groundwater recharge rates (60 – 160 mm.y-1) and (ii) the distribution of stream flow contributions between 2001 and 2014 (i.e. 55 % from groundwater, 38 % from runoff and 8 % from WWTP). Moreover, the use of geochemical and isotopic tracers (e.g. Cl-, NO3-, SO42-, 222Rn, δ18Owater, δ2Hwater) confirmed the large impact of groundwater on stream flow and quality.The hydrological dynamics of the Yvette stream and its tributaries are similar because of the homogeneity of the geomorphological context of the catchment. The flood events are really fast (on the order of hours) and low-flow conditions can be observed in every season. The discretization of the Yvette catchment in 11 sub-watersheds highlighted a divergence between the topographical and hydrogeological catchments. This generates a water deficit in some tributaries heads (e.g. Mérantaise, Ru des Vaux) in favor of some others (e.g. Rhodon). The matching limits of these catchments can only be made on the Yvette channel. During the 2001 – 2014 period, considering a fairly constant WWTP contribution, the groundwater discharge provides more than 90 % of the stream flow during low-flow conditions. This highlights a stream quality dominated by groundwater discharge. However, groundwater chemistry largely varies over the catchment. To study this phenomenon, a small-scale field work has been directed on the Rhodon stream, a main tributary of the Yvette River. At this scale, the groundwater discharge appeared to have two main pathways: 15 % come from the streambed while 85 % transit in wetlands before going to the stream. Within these wetlands, a large part of groundwater flows at the surface and has high levels of nutrients, whereas a small part (6 %) goes through sediments and is nutrients free. reduces The purifying power of these wetlands, significantly reduced by this distribution, is likely related to historical drainage and reinforces the direct connection between the stream and groundwater quality. On the Yvette catchment, the stratification of groundwater chemistry is due to several recharge processes (e.g. pond water infiltration, WWTP effluents infiltration, wetlands water infiltration). Small sub-watersheds (< 50 km²) seem to be dominated by (i) this stratification, and (ii) the WWTP discharges which can contribute from 30 % to 50 % to dissolved fluxes in the streams. The main channel of the Yvette stream primarily depends of the mixing of its tributaries waters. The methods developed here allowed highlighting (i) differences of catchment functioning according to the scale used, and (ii) the utmost importance of the small-scale assessment to understand/decipher and manage streams at larger scales

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29

McKillip, Michael Lee. "Coupling the Hydrodynamic and Water Quality Model CE-QUAL-W2 With a Multi-Trophic Fish Bio-Energetics Model for Lake Roosevelt, Washington." PDXScholar, 2008. https://pdxscholar.library.pdx.edu/open_access_etds/3078.

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Grand Coulee Dam created Franklin D. Roosevelt Lake as part of the Columbia Basin Project. Located in northeastern Washington State, the Project provides economically important hydropower (19 billion kilowatt hours per year), irrigation (225,000 ha), flood control, and sport fishing ($5 to 20 million annually). A good system understanding aids in balancing these beneficial uses for the 230 km long reservoir. The reservoir's atypical 45-day mean residence time is much shorter than a typical lake, and much longer than for a riverine dam. The spring freshet requires drawdowns of 15 to 20 m for flood control—the driving characteristic of reservoir operations. A physically based two-dimensional hydrodynamic and water quality model, CE-QUAL-W2 Version 3.5 (Cole and Wells, 2006), is coupled with a fish bioenergetics model based on the Stockwell and Johnson model (1997, 1999) to examine the effects of hydrodynamics on the reservoir algae-zooplankton-kokanee food web. This model was applied and calibrated to Lake Roosevelt with model improvements of multiple zooplankton compartments and zooplankton omnivory. Calibration parameters included temperature, dissolved oxygen, nutrients, algae, and zooplankton. The fish bioenergetics model is applied over the entire reservoir model space to generate a spatial and temporal fish growth potential distribution. The fish model refinements include sub-daily time-steps and an optimized vertical foraging strategy. The linked model suggests that kokanee fish growth potential is seasonally limited by both warm water and prey densities. While the lake ecology is significantly affected by the reservoir operations in general, the pelagic fish growth potential did not appear sensitive to minor changes in reservoir operations. However, the model suggests that the advantageous foraging locations shift seasonally and that optimal foraging strategies are dependent on fish size.

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30

Castro, Marcelo Mendes de. "Modelação matemática de lagos e reservatórios: caso do Reservatório Billings." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/3/3147/tde-18082010-165433/.

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Modelos numéricos são importantes ferramentas para avaliação do comportamento de corpos hídricos, notadamente com relação ao decaimento e mistura de constituintes ao longo do tempo. Neste trabalho apresenta-se o método empregado para adaptação e aplicação de um modelo matemático hidrodinâmico 2DH para simulação de variáveis de qualidade das águas a reservatórios rasos ou polimíticos. A descrição do desenvolvimento do modelo empregado (IPH-ECO), do processo de análise das condições do reservatório, seleção de dado intervenientes, discretização espacial e temporal, definição das condições de contorno hidrológicas e de aporto de cargas poluentes, bem como a definição espacial dos pontos de controle para aferição e validação são discutidos. São apresentados os resultados da resposta do modelo aplicado ao Reservatório Billings, em São Paulo.
Numerical models are strong tools to evaluate the fate of pollutants in lakes and reservoirs under transient conditions. This article brings the steps employed for preparation and implementation of a hydrodynamic 2DH model to simulate water quality variables in shallow or polymitc lakes. Description of the adaptation and implementation of IPH-ECO model process, compiling and setting of the hydrological and constituent loadings, spatial and temporal discretization and selection of control points are demonstrated and discussed. Some results of model calibration for Billings Reservoir, Sao Paulo, Brazil, are also presented.

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Lemos, Wictor Edney Dajtenko. "PrevisÃo climÃtica sazonal do regime tÃrmico e hidrodinÃmico de reservatÃrio." Universidade Federal do CearÃ, 2015. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=14582.

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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico
A dinÃmica dos processos relacionados Ã qualidade da Ãgua em reservatÃrios Ã funÃÃo da sua morfologia, da aÃÃo das variÃveis meteorolÃgicas e das afluÃncias e defluÃncias, em maior grau. Prever o comportamento hidrodinÃmico de reservatÃrios e o impacto causado por mudanÃas ou variabilidades na forÃante meteorolÃgica Ã essencial ao gerenciamento da qualidade da Ãgua e foi o objetivo principal desta tese. Para tanto foram utilizados modelos climÃticos, hidrolÃgicos, hidrodinÃmicos e de balanÃo de energia, em cascata. O comportamento da hidrodinÃmica resultante da modelagem mostrou resultados consonantes com reservatÃrios de regiÃes tropicais, representando os padrÃes diÃrios de circulaÃÃo e a formaÃÃo de estratificaÃÃes tÃrmicas no reservatÃrio modelado. As principais variaÃÃes hidrodinÃmicas sazonais puderam ser modeladas, ainda que com um alto Ãndice de incerteza. Foi realizado um monitoramento no reservatÃrio Pereira de Miranda que forneceu meios para dar inÃcio ao ciclo de modelagem e monitoramento integrado. Foi apresentada a tÃcnica de downscaling dinÃmico para a obtenÃÃo das variÃveis meteorolÃgicas de previsÃo regionalizadas, demostrando algumas possibilidades de aplicaÃÃo dos resultados dos modelos climÃticos na modelagem hidrodinÃmica de reservatÃrios, indispensÃvel na modelagem da qualidade da Ãgua. Os resultados mostraram a possibilidade de calibraÃÃo e validaÃÃo do modelo hidrodinÃmico CE-QUAL-W2 com o uso de dados de reanÃlise atmosfÃrica, aplicaÃÃo de tÃcnicas de previsÃo climÃtica na avaliaÃÃo e previsÃo dos padrÃes hidrodinÃmicos de reservatÃrios e a necessidade de um sistema de monitoramento como subsidiÃrio de informaÃÃes relevantes Ã modelagem, no sentido de melhorar os sistemas existentes e aumentar o nÃvel de conhecimento sobre a dinÃmica de reservatÃrios localizados no semiÃrido.
The dynamics of water quality related processes in reservoirs is a function of its morphology, the action of meteorological variables and defluÃncias inflows and, to a greater extent. Predict the hydrodynamic behavior of reservoirs and the impact of changes or variability in weather forcing is essential to the management of water quality and was the main objective of this thesis. Therefore, we used climate models, hydrological, hydrodynamic and energy balance in cascade. The behavior of the resulting hydrodynamic modeling showed results in line with tropical reservoirs, representing the daily patterns of movement and the formation of thermal stratification in modeled reservoir. The main hydrodynamic seasonal variations could be modeled, albeit with a high level of uncertainty. Monitoring on a Miranda Pereira reservoir that provided a means to begin the modeling and integrated monitoring cycle was performed. The dynamic downscaling technique to obtain the meteorological variables of regionalized forecast was presented, showing some application possibilities of the results of climate models in hydrodynamic modeling of reservoirs, essential in modeling of water quality. The results showed the possibility of calibration and validation of the hydrodynamic model CE-QUAL-W2 using atmospheric reanalysis data, application of climate prediction techniques in assessing and predicting the hydrodynamic patterns of tanks and the need for a monitoring system as Subsidiary information relevant to modeling, to improve existing systems and increase the level of knowledge about the dynamics of reservoirs located in the semiarid.

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32

Bierlein, Kevin Andrew. "Predicting induced sediment oxygen flux in oxygenated lakes and reservoirs." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/73502.

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Bubble plume oxygenation systems are commonly used to mitigate anoxia and its deleterious effects on water quality in thermally stratified lakes and reservoirs. Following installation, increases in sediment oxygen flux (JO2) are typically observed during oxygenation and are positively correlated with the bubble plume gas flow rate. Studies show that JO2 is controlled by the thickness of the diffusive boundary layer (DBL) at the sediment-water interface (SWI), which is in turn controlled by turbulence. As a result, JO2 can be quite spatially and temporally variable. Accurately predicting oxygenation-induced JO2 is vitally important for ensuring successful oxygenation system design and operation. Yet despite the current understanding of physical and chemical controls on JO2, methods for predicting oxygenation-induced JO2 are still based on empirical correlations and factors of safety. As hypolimnetic oxygenation becomes more widely used as a lake management tool for improving and maintaining water quality, there is a need to move from the current empirically based approach to a mechanistic approach and improve the ability to predict induced JO2. This work details field campaigns to investigate and identify appropriate models of oxygen supply to the SWI and oxygen demand exerted from the sediment, with the intent to use these models to predict oxygenation-induced JO2. Oxygen microprofiles across the SWI and near-sediment velocity measurements were collected in situ during three field campaigns on two oxygenated lakes, providing simultaneous measurements of JO2 and turbulence. Field observations show that oxygenation can increase JO2 by increasing bulk hypolimnetic oxygen concentrations, which increases the concentration gradient across the SWI. Oxygenation can also enhance turbulence, which decreases the DBL thickness and increases JO2. Existing models of interfacial flux were compared to field measurements to determine which model best predicted the observed JO2. Models based on the Batchelor scale, friction velocity, and film-renewal theory all agree reasonably well with field observations in both lakes. Additionally, the oxygen microprofiles were used to fit a transient model of oxygen kinetics in lake sediment and determine the appropriate kinetic model. Oxygen microprofiles in both lakes can be described using zero-order kinetics, rather than first-order kinetics. The interfacial flux and sediment kinetic models are incorporated into a coupled bubble plume and 3-D hydrodynamic lake model, allowing for spatial and temporal variation in simulated JO2. This comprehensive model was calibrated and validated to field data from two separate field campaigns on Carvin's Cove Reservoir, Virginia. Simulated temperature profiles agreed quite well with field observations, while simulated oxygen profiles differed from observed profiles, particularly in the bottom 1 m of the water column. The model overestimates oxygen concentrations near the sediment, which results in higher simulated JO2 than was observed during the field campaigns. These discrepancies are attributed to oxygen-consuming chemical processes, such as oxidation of soluble metals, which are not accounted for in the hydrodynamic model. Despite this, the model is still able to capture the impact of bubble plume operation on JO2, as simulated JO2 is higher when the diffusers are operating. With some additional improvements to the water quality modeling aspects of the model, as well as further calibration and validation, the model should be able to reproduce observed JO2 provided oxygen concentrations near the SWI are accurately reproduced as well. The current work is an attempt to push toward a comprehensive lake oxygenation model. A comprehensive model such as this should improve the ability to predict oxygenation-induced JO2 and lead to improvements in the design and operation of hypolimnetic oxygenation systems.
Ph. D.

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33

Seiler, Lilian Marques Nogueira. "Modelagem numérica da Lagoa dos Patos: variação espacial e temporal da qualidade da água." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/21/21136/tde-23042015-103406/.

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Este trabalho aborda a influência da hidrodinâmica da Lagoa dos Patos (RS) no comportamento de variáveis indicadoras da qualidade da água, como o material em suspensão, o oxigênio dissolvido, os nutrientes inorgânicos dissolvidos e a clorofila-a. Adicionalmente, o trabalho apresenta uma avaliação do efeito do lançamento de efluentes na magnitude das concentrações destas variáveis e nas suas inter-relações. Para o desenvolvimento deste estudo aplicou-se o modelo numérico MOHID 2D, utilizado com êxito na gestão ambiental de regiões costeiras. Os resultados indicam que a Lagoa dos Patos é um corpo lagunar heterogêneo no qual sua hidrodinâmica é regida principalmente pela atuação dos ventos e da vazão fluvial. Esses fatores influenciam diretamente o comportamento das variáveis estudadas. A presença de efluentes altera significativamente a magnitude das concentrações dos nutrientes e da clorofila-a no ambiente, principalmente nas regiões próximas aos locais de lançamento. A modelagem numérica é uma importante ferramenta para a gestão ambiental de sistemas dinâmicos e que variáveis ecológicas são condicionadas pelas suas inter-relações e pela circulação do sistema.
This work assesses the influence of Patos Lagoon- RS hydrodynamics in the behavior of water quality indicator variables as like suspended material, dissolved oxygen, dissolved inorganic nutrients and chlorophyll-a. Also gives an assessment of the effect of effluent discharge in the magnitude of the concentrations of these variables and in their interrelationships. To develop this study we applied the numerical model MOHID 2D, successfully applied in environmental management of coastal areas. The results indicate that Patos Lagoon is a heterogeneous system in which its hydrodynamic is governed mainly by the action of wind and river flow, which directly influence the behavior of water quality variables. Furthermore, the presence of effluent significantly changes the magnitude of the nutrients and chlorophyll-a concentration, particularly in areas close to the sewage launch sites. We concluded that the numerical modeling is an important tool for the dynamics systems management and that ecological variables are not only conditioned by their interrelations, but also by system circulation.

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34

FranÃa, Josefa Marciana Barbosa de. "AvaliaÃÃo da degradaÃÃo do AÃude Acarape do Meio-CE com uso de modelo matemÃtico e geotecnologia." Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11200.

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Um dos grandes desafios da gestÃo ambiental Ã compatibilizar a preservaÃÃo com os usos mÃltiplos, sendo fundamental o conhecimento dos fatores condicionantes das modificaÃÃes das condiÃÃes naturais dos reservatÃrios e respectiva bacia hidrogrÃfica. Neste contexto, o presente trabalho aborda temas como: caracterizaÃÃo morfomÃtrica da bacia hidrogrÃfica e hidrÃulica do aÃude Acarape do Meio â CE; simulaÃÃo da circulaÃÃo hidrodinÃmica para o ano de 2012 a partir do programa SisBaHiA, assim como, a estimaÃÃo do tempo de residÃncia e das taxas de renovaÃÃo; e para averiguar aspectos da evoluÃÃo dos processos de degradaÃÃo da qualidade da Ãgua, processou-se quatro imagem de satÃlite Landsat 5 â TM. A partir da anÃlise dos resultados da pesquisa, constatou-se que: a bacia hidrogrÃfica do aÃude Acarape do Meio tem aproximadamente 10,31% da Ãrea degradada; identificou-se que a bacia hidrÃulica tem formato dendrÃtico com elevado desenvolvimento de perÃmetro. Quanto aos aspectos relacionados Ã modelagem ambiental estimou-se que o comportamento da circulaÃÃo hidrodinÃmica apresentou baixa velocidade das correntes; a taxa de renovaÃÃo da Ãgua no perÃodo de chuva atingiu 100% nas Ãreas de reentrÃncias; tambÃm se identificou que o tempo de residÃncia Ã mais elevado nas Ãreas rasas e dendrÃticas. Com relaÃÃo Ã presenÃa de componentes Ãpticos ativos, constatou-se que ocorreu o aumento na resposta espectral das imagens Landsat 5 â TM, referente ao perÃodo de 11 anos (2001 a 2011), que se relaciona com o aumento da clorofila a ao longo dos anos, que Ã consequÃncia do processo de eutrofizaÃÃo.
One of the great challenges of environmental management is compatible the preservation with the water multiple uses, with fundamental knowledge of the factors conditioning the changes of the natural conditions of the reservoirs and their watershed. In this context, this paper ad-dresses topics such as: morphometric characterization of the Acarape do Meio (CearÃ State) river basin and it hydraulic weir; simulation of hydrodynamic circulation for the year 2012 with the SisBaHiA program, as well as the estimation of the residence time and renewal fees, and to investigate aspects of the evolution of the processes of degradation of water quality, from four satellite images Landsat 5 - TM. From the analysis of the survey results, it was found that the catchment area of the dam Acarape do Meio has approximately 10,31% of the degraded area and it was found that the hydraulic basin has dendritic format with high perimeter development. For the aspects related to environmental modeling, it was estimated that the hydrodynamic behavior of circulating currents showed low speeds, the renewal rate of the water during the rainy season reached 100% in the areas of recesses and also it was found that the residence time is higher in the shallow and dendritic areas. With respect to the presence of active optical components, it was found that there was an increase in the spectral response of Landsat 5 - TM for the 11 years period (2001 to 2011), which relates to the increase of chlorophyll a throughout the years, which is a eutrophication consequence.

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35

Singleton, Vickie L. "Hypolimnetic Oxygenation: Coupling Bubble-Plume and Reservoir Models." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/26722.

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When properly designed, hypolimnetic aeration and oxygenation systems can replenish dissolved oxygen in water bodies while preserving stratification. A comprehensive literature review of design methods for the three primary devices was completed. Using fundamental principles, a discrete-bubble model was first developed to predict plume dynamics and gas transfer for a circular bubble-plume diffuser. This approach has subsequently been validated in a large vertical tank and applied successfully at full-scale to an airlift aerator as well as to both circular and linear bubble-plume diffusers. The unified suite of models, all based on simple discrete-bubble dynamics, represents the current state-of-the-art for designing systems to add oxygen to stratified lakes and reservoirs. An existing linear bubble plume model was improved, and data collected from a full-scale diffuser installed in Spring Hollow Reservoir, Virginia (U.S.A.) were used to validate the model. The depth of maximum plume rise was simulated well for two of the three diffuser tests. Temperature predictions deviated from measured profiles near the maximum plume rise height, but predicted dissolved oxygen profiles compared very well to observations. Oxygen transfer within the hypolimnion was independent of all parameters except initial bubble radius. The results of this work suggest that plume dynamics and oxygen transfer can successfully be predicted for linear bubble plumes using the discrete-bubble approach. To model the complex interaction between a bubble plume used for hypolimnetic oxygenation and the ambient water body, a model for a linear bubble plume was coupled to two reservoir models, CE-QUAL-W2 (W2) and Si3D. In simulations with a rectangular basin, predicted oxygen addition was directly proportional to the update frequency of the plume model. W2 calculated less oxygen input to the basin than Si3D and significantly less mixing within the hypolimnion. The coupled models were then applied to a simplified test of a full-scale linear diffuser. Both the W2 and Si3D coupled models predicted bulk hypolimnetic DO concentrations well. Warming within the hypolimnion was overestimated by both models, but more so by W2. The lower vertical resolution of the reservoir grid in W2 caused the plume rise height to be over-predicted, enhancing erosion of the thermocline.
Ph. D.

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36

Heller, Winfried. "Hydro-dynamic Effects with Particular Consideration of Water Quality and their Measurement Methods." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1141217614058-76453.

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Die Entwicklung der Strömungsmechanik im 20. Jahrhundert wurde auch durch intensive Forschungen geprägt, um die zahlreichen in der Praxis auftretenden hydrodynamischen Effekte zu ergründen, die physikalischen Abläufe und Zusammenhänge zu verstehen und diese mathematisch zu beschreiben. Dies wurde notwendig, da mit den hydrodynamischen Grundgleichungen allein keine Beschreibung der aus den Fluideigenschaften resultierenden Erscheinungen in Flüssigkeitsströmungen möglich war. Um die Qualität der Flüssigkeiten bezüglich ihres Gasgehaltes und ihrer Keimverteilung beurteilen zu können, wurden mit Beginn des 20. Jahrhunderts unterschiedliche Messmethoden und Apparaturen entwickelt und gebaut. Diese Entwicklung ließ sich annähernd vollständig darstellen, hierbei besonders die Entwicklungen von Apparaturen zur Bestimmung des Gesamtgasgehaltes. Neben der zumeist schwierigen Handhabung dieser Messgeräte und Methoden wird dabei nur der Einfluss einzelner Messgrößen, wie Gesamtgasgehalt, Gelöstsauerstoffgehalt, Keimgehalt, Keimverteilung und Keimgrößenverteilung auf hydrodynamische Effekte untersucht. Die aber in realen Strömungen auftretenden Wechselwirkungen zwischen den Einflussgrößen werden nicht berücksichtigt. Schon am Ende des 19. Jahrhundert begann die Entwicklung von Geräten und Methoden zur Bestimmung von Zugspannungen in Flüssigkeiten. Den anfänglich statischen Methoden folgten mit Beginn der 70-er Jahre des 20. Jahrhunderts die bis heute andauernden Entwicklungen dynamischer Methoden. Während für speziell behandelte Flüssigkeiten unter statischen Bedingungen Zugspannungen von einigen hundert bar gemessen wurden, liegen die typischen Werte für Wasser mit der Wirbel- oder Dralldüse gemessen, zwischen null und zwei bar. Das zeigt den starken Einfluss der Wechselwirkungen aller Einflussgrößen auf die Zugspannung in strömenden Flüssigkeiten. Außer auf die Schallgeschwindigkeit und die Druckverteilung an Profilen hat die Wasserqualität einen besonders starken Einfluss auf bestimmte Kavitationserscheinungen. Weltweite Kavitationstests zeigten, dass ohne Bestimmung der aktuellen Zugspannung des Testwassers keine reproduzierbaren Ergebnisse bezüglich des Kavitationsbeginns möglich sind. Bei Untersuchungen zur Kavitationserosion wurde der Zusammenhang zwischen Wasserqualität und erosiver Aggressivität und Erosionsrate eindeutig nachgewiesen. Die permanente Messung der Zugspannung der Testflüssigkeit ist bei Kavitationsexperimenten an Modellkörpern offensichtlich zwingend notwendig, um die Messergebnisse korrekt interpretieren zu können. Kavitationserscheinungen an Profilen oder Durchströmteilen bewirken Änderungen von Auftriebs-, Widerstands- und Verlustbeiwerten in Abhängigkeit vom Fortschrittsgrad der Kavitation. Hierbei spielen die Beeinflussung der Transition, Ablösung, Versperrung und Druckverteilung eine besondere Rolle. Bei elektrisch leitfähigen Fluiden ist die Qualität durch die Leitfähigkeit bestimmt. Mittels elektromagnetischer Felder werden Lorentzkräfte erzeugt, deren Wirkung sich zeigt in der Unterdrückung von Strömungsablösung, Widerstandsverringerung und stärkerem Auftrieb. Vielfältige experimentelle Forschungsergebnisse auf dem Gebiet der Strömungsmechanik haben gezeigt, dass für die Beschreibung realer Strömungsvorgänge die Qualität des Fluides berücksichtigt werden muss. Da die vielen Einflussgrößen in der Strömung permanenten Wechselwirkungen unterliegen, führt letztlich die Summe aller Einzeleinflüsse auf die genannten Effekte. Für die Bestimmung der Wasserqualität z.B. bei Kavitationsexperimenten kann die Zugspannung des Testwassers gemessen werden, wodurch die genauere mathematische Beschreibung des Kavitationsbeginns möglich wird
The development of fluid mechanics during the twentieth century has been affected by intense research in order to fathom numerous practically relevant hydrodynamic effects, to understand the physical processes and correlations and to describe them mathematically. This became necessary because employing only the fundamental hydrodynamic equations, the description of certain phenomena in fluid flows caused by fluid properties was impossible. In order to assess the quality of fluids regarding their gas contents and their nuclei distributions, various measuring methods and devices have been developed and constructed since the beginning of the twentieth century. This historical development could be described nearly completely in this work, particularly the development of devices to determine the total gas content. Apart from the mostly difficult handling of these measurement methods and devices, only the influence of single parameters such as the total gas content, the dissolved oxygen content, nucleus content, nucleus distribution and the distribution of nucleus sizes on hydrodynamic effects was examined. However, the correlations between these single parameters, as they occur in real flows, could not be taken into consideration. As early as the end of the ninetieth century the development of methods and devices began to determine the tensile strength of fluids. The initially static methods have been followed by the developments of dynamic methods since the beginning of the 1970s. While for specially prepared fluids, tensile strengths of several hundred bar were measured under static conditions, the typical values for water, measured with the eddy and swirl nozzle, range between zero and two bar. This illustrates the strong influence of interactions between all parameters on the tensile strength in flowing fluids. Except for sound velocity and pressure distribution at profiles, water quality particularly affects certain cavitation phenomena. Various cavitation tests around the world have shown that without determining the actual tensile strength of the test water, it is impossible to obtain reproducible results regarding cavitation inception. In experiments concerning cavitation erosion, the correlation between water quality, erosive aggressiveness and erosion rate was proven unmistakably. Evidently, permanent measurement of the test fluid?s tensile stress during cavitation experiments with model bodies is compulsory in order to be able to interpret measurement results correctly. Cavitation phenomena at profiles or other parts affected by flow cause changes of lift, drag and loss coefficients depending on the degree of the cavitation progress. The influence of transition, detachment, obstruction and pressure distribution plays a special role. The quality of electrically conductive fluids is determined by their conductivity. By means of electromagnetic fields Lorentz-forces are generated, whose effect can be observed in lessening of flow detachment, drag reduction and increased lift. Manifold experimental research results in the area of fluid mechanics have proven that the fluid quality must be taken into account when describing real flow processes. Since the many flow parameters are subject to permanent interaction, ultimately, the sum of all single parameters lead to the effects mentioned. For the determination of the water quality such as in cavitation experiments, the tensile stress of the water can be measured making the mathematical description of cavitation inception possible. - (The German online version of this thesis for qualification as university teacher has been published under the titel "Hydrodynamische Effekte unter besonderer Berücksichtigung der Wasserqualität und ihre Messverfahren" - http://hsss.slub-dresden.de/hsss/servlet/hsss.urlmapping.MappingServlet?id=1141215758714-7391)

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37

Gokgoz, Kilic Sinem. "Dynamic fugacity modeling in environmental systems." Diss., Atlanta, Ga. : Georgia Institute of Technology, 2008. http://hdl.handle.net/1853/22557.

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Thesis (M. S.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Aral, Mustafa; Committee Member: Guan, Jiabao; Committee Member: Pavlostathis, Spyros; Committee Member: Uzer, Turgay; Committee Member: Yiacoumi, Sotira.

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38

Graepin, Cristiane. "VIABILIDADE DA UTILIZAÇÃO DO MÉTODO DELTA APROXIMADO PARA DETERMINAÇÃO DO COEFICIENTE DE REAERAÇÃO EM RIOS." Universidade Federal de Santa Maria, 2016. http://repositorio.ufsm.br/handle/1/7657.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The dissolved oxygen is an important indicator that shows water quality variation in rivers, caused by the release/accumulation of organic matter. The determination of the reaeration coefficient is indispensable, due to the consumption of dissolved oxygen for the organic matter oxidation. The reaeration coefficient can be determined by empirical models or experimental methods. The experimental methods are generally expensive and slow. However, the Approximate Delta Method proposed by McBride and Chapra (2005) is an experimental method of easy application and low cost. This method is based on surface reaeration estimation, primary production, and respiration. Basically, it is estimated by means of daytime measurements of dissolved oxygen. The main gol was to analyze the application viability of the Approximate Delta Method to determine the reaeration coefficient in watershed. This study was carried out in five watersheds: Cancela-Tamandaí, Menino Deus II, Menino Deus IV, João Goulart and RSC 287. The reaeration coefficient is influenced by hydrodynamic characteristics of the rivers. Thus, the velocity, depth, and flow were monitored. It was determined the temperature of the water and the dissolved oxygen concentrations during the photoperiod, and it was estimated the organic load in the rivers. The application of the Approximate Delta Method was viable only in João Goulart and RSC 287 basins. The Cancela-Tamandaí basin does not presented an adequated dissolved oxygen profile. This was due to the high release of organic matter in the river. The Menino Deus II basin also presented unviability. This was due to the absence of an adequate dissolved oxygen profile. In the Menino Deus IV basin occurred overestimation of the coefficients, when was possible your estimation. In this basin, the minimum deficit in most of the dissolved oxygen profiles was before of the solar noon, avoided the application of the method. In João Goulart basin was viable the application of the method, but with some limitations: flows until 1.00 m3/s; there should be regular presence of organic load; and the time between the dissolved oxygen minimum deficit and the solar noon do not should be too low. The RSC 287 basin was viable in your normal hydrodynamic characteristics. The method was not viable with flow higher than 3.64 m3/s, and in the agriculture irrigation season. Finally, the Approximate Delta Method presented unviability in some conditions: flow greater than 1.00 m3/s for João Goulart basin, and then 3.64 m3/s in the RSC 287 basin; rivers with organic content very low or very high; low time between the dissolved oxygen minimum deficit and solar noon; low temperatures; and rivers with captation of the water. In the João Goulart basin, it was calculated the Pearson correlation coefficient between reaeration coefficient and the others variables. It was found significant correlation of the reaeration coefficient with the flow, depth, and velocity. However, the Approximate Delta Method showed experimentally to be easy to use and low cost. However, with a variety of limitations in its application, making it unviability to certain conditions.
O oxigênio dissolvido é um indicador importante que demonstra alterações da qualidade da água em rios, provocadas pelo lançamento/acúmulo de matéria orgânica. A determinação do coeficiente de reaeração torna-se indispensável, devido ao consumo de oxigênio dissolvido na oxidação da matéria orgânica. O coeficiente de reaeração pode ser determinado por modelos de natureza empírica ou métodos experimentais. Os métodos experimentais geralmente são caros e demorados. Porém, o Método Delta Aproximado proposto por McBride e Chapra (2005) é um método experimental de fácil aplicação e baixo custo. O método se baseia na estimativa de reaeração superficial, produção primária e respiração, basicamente por meio de medições diurnas do oxigênio dissolvido. O objetivo principal desse estudo foi analisar a viabilidade de aplicação do Método Delta Aproximado para determinar o coeficiente de reaeração em bacias hidrográficas. O estudo foi realizado em cinco bacias hidrográficas: Cancela-Tamandaí, Menino Deus II, Menino Deus IV, João Goulart e RSC 287. O coeficiente de reaeração é influenciado pelas características hidrodinâmicas dos rios. Assim, nas campanhas foram determinadas a velocidade, profundidade e vazão. Determinou-se a temperatura da água, as concentrações de oxigênio dissolvido, durante o fotoperíodo, e estimou-se a carga orgânica nos rios. Neste estudo a aplicação do Método Delta Aproximado foi viável apenas nas bacias João Goulart e RSC 287. A bacia Cancela-Tamandaí não apresentou um perfil de oxigênio dissolvido adequado, devido ao elevado lançamento de matéria orgânica no rio. A bacia Menino Deus II também apresentou inviabilidade, devido à ausência de um perfil de oxigênio dissolvido adequado. A bacia Menino Deus IV apresentou superestimação dos valores do coeficiente, e em grande parte das campanhas o mínimo déficit de oxigênio dissolvido ocorreu antes do meio-dia solar, impossibilitando a aplicação do método. Na bacia João Goulart foi viável a aplicação do método, porém com as seguintes limitações: viável em vazões de até 1,00 m3/s; deve haver presença regular de carga orgânica; o tempo entre o mínimo déficit de oxigênio dissolvido e o meio-dia solar não deve ser muito baixo. A bacia RSC 287 apresentou-se viável quanto à aplicação do método em suas características normais, no entanto nas campanhas com vazões maiores que 3,64 m3/s, e com presença de captação de água para irrigação o método não foi viável. Enfim, o Método Delta Aproximado apresentou inviabilidade nas seguintes condições: vazão maior que 1,00 m3/s para a bacia João Goulart e maior que 3,64 m3/s na bacia RSC 287; rios com teor de matéria orgânica muito alto ou muito baixo; baixo tempo entre o mínimo déficit de oxigênio dissolvido e o meio-dia solar; temperaturas baixas; e rios com captação de água. Na bacia João Goulart, onde o método pôde ser aplicado, foi feito correlação de Pearson com o coeficiente e as variáveis analisadas. Verificou-se correlação positiva significativa do coeficiente com a vazão, profundidade e velocidade. Contudo, o Método Delta Aproximado demonstrou experimentalmente ser de fácil aplicação e baixo custo. Porém, com uma diversidade de limitações em sua aplicação, tornando-o inviável em determinadas condições.

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39

Förster, Saskia. "An analysis of hydraulic, environmental and economic impacts of flood polder management at the Elbe River." Phd thesis, Universität Potsdam, 2008. http://opus.kobv.de/ubp/volltexte/2008/2726/.

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Flood polders are part of the flood risk management strategy for many lowland rivers. They are used for the controlled storage of flood water so as to lower peak discharges of large floods. Consequently, the flood hazard in adjacent and downstream river reaches is decreased in the case of flood polder utilisation. Flood polders are usually dry storage reservoirs that are typically characterised by agricultural activities or other land use of low economic and ecological vulnerability. The objective of this thesis is to analyse hydraulic, environmental and economic impacts of the utilisation of flood polders in order to draw conclusions for their management. For this purpose, hydrodynamic and water quality modelling as well as an economic vulnerability assessment are employed in two study areas on the Middle Elbe River in Germany. One study area is an existing flood polder system on the tributary Havel, which was put into operation during the Elbe flood in summer 2002. The second study area is a planned flood polder, which is currently in the early planning stages. Furthermore, numerical models of different spatial dimensionality, ranging from zero- to two-dimensional, are applied in order to evaluate their suitability for hydrodynamic and water quality simulations of flood polders in regard to performance and modelling effort. The thesis concludes with overall recommendations on the management of flood polders, including operational schemes and land use. In view of future changes in flood frequency and further increasing values of private and public assets in flood-prone areas, flood polders may be effective and flexible technical flood protection measures that contribute to a successful flood risk management for large lowland rivers.
Flutpolder werden zum gezielten Rückhalt von Wasser eingesetzt, um Spitzenabflüsse von großen Hochwassern zu senken. Dadurch wird im Falle des Flutpoldereinsatzes die Hochwassergefährdung für flussab gelegene Flussabschnitte verringert. Flutpolder sind meist trockene Staubecken, die typischerweise durch landwirtschaftliche Nutzung gekennzeichnet sind. Ziel der Dissertation ist die Analyse von hydraulischen, ökologischen und ökonomischen Auswirkungen des Einsatzes von Flutpoldern, um daraus Schlussfolgerungen für ihre Bewirtschaftung zu ziehen. Dazu werden numerische Modelle zur Simulation der Hydrodynamik und Wassergüte sowie ein landwirtschaftliches Schadenmodell gemeinsam in einem integrativen Ansatz eingesetzt. Ein Untersuchungsgebiet ist ein existierendes Flutpoldersystem am Nebenfluss Havel, welches während der Elbeflut im Sommer 2002 zum Einsatz kam. Das zweite Untersuchungsgebiet ist ein geplanter Flutpolder, welcher sich bisher noch in einem frühen Planungsstadium befindet. Darüber hinaus werden numerische Modelle verschiedener räumlicher Dimensionalität von null- bis zwei-dimensional angewandt, um ihre Eignung für hydrodynamische und Wassergütesimulationen von Flutpoldern hinsichtlich der Leistungsfähigkeit und des Modellierungsaufwands zu bewerten. Die Dissertation schließt mit übergreifenden Empfehlungen zur Bewirtschaftung von Flutpoldern einschließlich Kontrollstrategien und Landnutzung ab. Im Hinblick auf zukünftige Änderungen in der Auftretenshäufigkeit von Hochwassern und weiterhin ansteigenden Werten von privatem und öffentlichem Vermögen in überflutungsgefährdeten Gebieten stellen Flutpolder ein effektive und flexible Maßnahmen des technischen Hochwasserschutzes dar, welche zu einem erfolgreichen Hochwasserrisikomanagement großer Tieflandflüsse beitragen.

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40

Tang, Gula. "Research on distributed warning system of water quality in Mudan river based on EFDC and GIS." Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAD023/document.

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Le système de simulation et d'avis précoce d'alerte est un outil puissant pour la surveillance de la qualité de l'eau de la rivière Mudan, une rivière importante dans les régions froides du nord-est de la Chine et qui se jette finalement dans la rivière de l'Amour en Russie. Ainsi la qualité de l'eau dans la rivière Mudan est une préoccupation importante non seulement au niveau local et régional,mais aussi au niveau international. L'objectif de cette étude est de créer un système de simulation et d'avis précoce d'alerte pour que la distribution spatio-temporelle de la qualité de l'eau durant les périodes de couverture glaciaire et d'eaux libres soit simulée et visualisée précisément et afin que l'on puisse appréhender la variation spatiale de polluants sur le cours de rivière. La thèse est structurée en 7 chapitres. Dans le premier chapitre nous décrivons le contexte de l'étude et faisons un état de lieu des recherches actuelles. Dans le chapitre Il, la comparaison des modèles principaux disponibles pour l'évaluation de la qualité de l'eau est réaliser ainsi que le choix du meilleur modèle comme base pour créer le système de modélisation. Dans le chapitre Ill, la construction du modèle,les conditions limites requises et les paramètres pour le modèle ont été vérifiés et étalonnés. Une procédure de simulation distribuée est conçue dans le chapitre IV pour améliorer l'efficacité de la simulation. Le chapitre V concerne la programmation et la réalisation la de simulation distribuée et le chapitre VI les techniques fondamentales pour mettre en œuvre le système. Le chapitre VII est la conclusion. Il y a trois points innovants dans ce travail: un modèle bidimensionnel de dynamique de fluides de l'environnement pour la rivière Mudan, une méthode efficace du calcul distribué et un prototype de système de simulation et d'avis précoce d'alerte qui peuvent largement améliorer la capacité de surveillance et de gestion de la qualité de l'eau de la rivière Mudan ou d'autres rivières similaires
Simulation and Early Warning System (SEWS) is a powerful tool for river water quality monitoring. Mudan River, an important river in northeastern cold regions of China, can run out of China into Russia. Thus, the water quality of Mudan River is highly concerned not only locally andregionally but also internationally. Objective of this study is to establish an excellent SEWS of water quality so that the spatio-temporal distribution of water quality in both open-water and ice-covered periods can be accurately simulated and visualized to understand the spatial variation of pollutants along the river course. The dissertation is structured into 7 chapters, chapter 1 outlines the background of the study and reviews the current progress. Chapter Il compares the main available models for evaluating river water quality so that a better model can be selected as the basis to establish a modeling system for Mudan River. Chapter Ill establishes the model, the required boundary conditions and parameters for the model were verified and calibrated. Chapter IV, a distributed simulation procedure was designed to increase the simulation efficiency. Chapter V discusses more about the programing and operational issues of the distributed simulation. Chapter VI is about the core techniques to implement the system. Chapter VII is the conclusion of the study to summarize the key points and innovations of the study. The study has the following three points as innovation : a two-dimensional environmental fluid dynamics model for Mudan River, an efficient distributed model computational method and a prototype of SEWS, which can greatly improve the capability of monitoring and management of water quality in Mudan River and other similar rivers

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41

Heller, Winfried. "Hydrodynamische Effekte unter besonderer Berücksichtigung der Wasserqualität und ihre Messverfahren." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2006. http://nbn-resolving.de/urn:nbn:de:swb:14-1141215758714-73914.

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The development of fluid mechanics during the twentieth century has been affected by intense research in order to fathom numerous practically relevant hydrodynamic effects, to understand the physical processes and correlations and to describe them mathematically. This became necessary because employing only the fundamental hydrodynamic equations, the description of certain phenomena in fluid flows caused by fluid properties was impossible. In order to assess the quality of fluids regarding their gas contents and their nuclei distributions, various measuring methods and devices have been developed and constructed since the beginning of the twentieth century. This historical development could be described nearly completely in this work, particularly the development of devices to determine the total gas content. Apart from the mostly difficult handling of these measurement methods and devices, only the influence of single parameters such as the total gas content, the dissolved oxygen content, nucleus content, nucleus distribution and the distribution of nucleus sizes on hydrodynamic effects was examined. However, the correlations between these single parameters, as they occur in real flows, could not be taken into consideration. As early as the end of the ninetieth century the development of methods and devices began to determine the tensile strength of fluids. The initially static methods have been followed by the developments of dynamic methods since the beginning of the 1970s. While for specially prepared fluids, tensile strengths of several hundred bar were measured under static conditions, the typical values for water, measured with the eddy and swirl nozzle, range between zero and two bar. This illustrates the strong influence of interactions between all parameters on the tensile strength in flowing fluids. Except for sound velocity and pressure distribution at profiles, water quality particularly affects certain cavitation phenomena. Various cavitation tests around the world have shown that without determining the actual tensile strength of the test water, it is impossible to obtain reproducible results regarding cavitation inception. In experiments concerning cavitation erosion, the correlation between water quality, erosive aggressiveness and erosion rate was proven unmistakably. Evidently, permanent measurement of the test fluid?s tensile stress during cavitation experiments with model bodies is compulsory in order to be able to interpret measurement results correctly. Cavitation phenomena at profiles or other parts affected by flow cause changes of lift, drag and loss coefficients depending on the degree of the cavitation progress. The influence of transition, detachment, obstruction and pressure distribution plays a special role. The quality of electrically conductive fluids is determined by their conductivity. By means of electromagnetic fields Lorentz-forces are generated, whose effect can be observed in lessening of flow detachment, drag reduction and increased lift. Manifold experimental research results in the area of fluid mechanics have proven that the fluid quality must be taken into account when describing real flow processes. Since the many flow parameters are subject to permanent interaction, ultimately, the sum of all single parameters lead to the effects mentioned. For the determination of the water quality such as in cavitation experiments, the tensile stress of the water can be measured making the mathematical description of cavitation inception possible
Die Entwicklung der Strömungsmechanik im 20. Jahrhundert wurde auch durch intensive Forschungen geprägt, um die zahlreichen in der Praxis auftretenden hydrodynamischen Effekte zu ergründen, die physikalischen Abläufe und Zusammenhänge zu verstehen und diese mathematisch zu beschreiben. Dies wurde notwendig, da mit den hydrodynamischen Grundgleichungen allein keine Beschreibung der aus den Fluideigenschaften resultierenden Erscheinungen in Flüssigkeitsströmungen möglich war. Um die Qualität der Flüssigkeiten bezüglich ihres Gasgehaltes und ihrer Keimverteilung beurteilen zu können, wurden mit Beginn des 20. Jahrhunderts unterschiedliche Messmethoden und Apparaturen entwickelt und gebaut. Diese Entwicklung ließ sich annähernd vollständig darstellen, hierbei besonders die Entwicklungen von Apparaturen zur Bestimmung des Gesamtgasgehaltes. Neben der zumeist schwierigen Handhabung dieser Messgeräte und Methoden wird dabei nur der Einfluss einzelner Messgrößen, wie Gesamtgasgehalt, Gelöstsauerstoffgehalt, Keimgehalt, Keimverteilung und Keimgrößenverteilung auf hydrodynamische Effekte untersucht. Die aber in realen Strömungen auftretenden Wechselwirkungen zwischen den Einflussgrößen werden nicht berücksichtigt. Schon am Ende des 19. Jahrhundert begann die Entwicklung von Geräten und Methoden zur Bestimmung von Zugspannungen in Flüssigkeiten. Den anfänglich statischen Methoden folgten mit Beginn der 70er Jahre des 20. Jahrhunderts die bis heute andauernden Entwicklungen dynamischer Methoden. Während für speziell behandelte Flüssigkeiten unter statischen Bedingungen Zugspannungen von einigen hundert bar gemessen wurden, liegen die typischen Werte für Wasser mit der Wirbel- oder Dralldüse gemessen, zwischen null und zwei bar. Das zeigt den starken Einfluss der Wechselwirkungen aller Einflussgrößen auf die Zugspannung in strömenden Flüssigkeiten. Außer auf die Schallgeschwindigkeit und die Druckverteilung an Profilen hat die Wasserqualität einen besonders starken Einfluss auf bestimmte Kavitationserscheinungen. Weltweite Kavitationstests zeigten, dass ohne Bestimmung der aktuellen Zugspannung des Testwassers keine reproduzierbaren Ergebnisse bezüglich des Kavitationsbeginns möglich sind. Bei Untersuchungen zur Kavitationserosion wurde der Zusammenhang zwischen Wasserqualität und erosiver Aggressivität und Erosionsrate eindeutig nachgewiesen. Die permanente Messung der Zugspannung der Testflüssigkeit ist bei Kavitationsexperimenten an Modellkörpern offensichtlich zwingend notwendig, um die Messergebnisse korrekt interpretieren zu können. Kavitationserscheinungen an Profilen oder Durchströmteilen bewirken Änderungen von Auftriebs-, Widerstands- und Verlustbeiwerten in Abhängigkeit vom Fortschrittsgrad der Kavitation. Hierbei spielen die Beeinflussung der Transition, Ablösung, Versperrung und Druckverteilung eine besondere Rolle. Bei elektrisch leitfähigen Fluiden ist die Qualität durch die Leitfähigkeit bestimmt. Mittels elektromagnetischer Felder werden Lorentzkräfte erzeugt, deren Wirkung sich zeigt in der Unterdrückung von Strömungsablösung, Widerstandsverringerung und stärkerem Auftrieb. Vielfältige experimentelle Forschungsergebnisse auf dem Gebiet der Strömungsmechanik haben gezeigt, dass für die Beschreibung realer Strömungsvorgänge die Qualität des Fluides berücksichtigt werden muss. Da die vielen Einflussgrößen in der Strömung permanenten Wechselwirkungen unterliegen, führt letztlich die Summe aller Einzeleinflüsse auf die genannten Effekte. Für die Bestimmung der Wasserqualität z.B. bei Kavitationsexperimenten kann die Zugspannung des Testwassers gemessen werden, wodurch die genauere mathematische Beschreibung des Kavitationsbeginns möglich wird. - (Diese Arbeit liegt auch in englischer Sprache unter dem Titel "Hydro-dynamic effects with particular consideration of water quality an their measurement methods" in elektronischer Form vor - http://hsss.slub-dresden.de/hsss/servlet/hsss.urlmapping.MappingServlet?id=1141217614058-7645)

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42

Batista, Silvana Simone. "Avaliação dos efeitos de ações antrópicas sobre o sistema costeiro de Ubatuba (SP) através de modelagem ambiental." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/106/106132/tde-02062016-152009/.

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A região de Ubatuba, sendo polo de atração turística, sofre influência das atividades humanas que modificam algumas características dos corpos de água, devido ao aporte de dejetos humanos, à descarga de poluentes e ao intenso tráfego de embarcações. O objetivo desse trabalho foi avaliar os efeitos das ações antrópicas sobre o sistema costeiro de Ubatuba por meio do estudo dos processos de transporte e difusão de poluentes, através de modelos que descrevem os mecanismos e as reações envolvidas na dispersão de hidrocarbonetos de petróleo (HPAs) e indicadores microbiológicos (coliformes termotolerantes e enterococos) na água do mar. Foram utilizados os módulos do sistema de modelagem ambiental Delft3D. O módulo hidrodinâmico foi implementado em uma grade numérica cobrindo a plataforma continental adjacente ao litoral norte de São Paulo. Da análise e validação dos resultados do módulo hidrodinâmico, concluiu-se que o modelo reproduziu satisfatoriamente a circulação marinha na região (valores de Skill entre 0,67 e 1,00). A associação dos dados de poluição com os resultados da hidrodinâmica permitiu estudar os mecanismos de dispersão dos poluentes nas enseadas do Flamengo e das Palmas através do módulo de qualidade da água. A concentração de coliformes calculada pelo modelo atingiu o máximo de 1850 NMP/100mL na Enseada do Flamengo, no verão; no caso dos HPAs, o teor máximo foi de 0,92 µg/L. As partes internas da Enseada do Flamengo têm a circulação da água reduzida, bem como a dispersão de poluentes. Os resultados sugerem que os teores de HPAs tiveram menor decaimento ao longo do tempo, o que se deve, provavelmente, às características da região, como baixo hidrodinamismo e baixo teor de nutrientes, que dificultam os processos de degradação de hidrocarbonetos. Por outro lado, os resultados indicaram um decaimento considerável na densidade de bactérias. As taxas de mortalidade de coliformes termotolerantes tiveram alta correlação linear positiva com a salinidade e temperatura (r = 0,94 e r = 0,99, respectivamente) e as taxas de mortalidade devido à radiação solar apresentaram uma boa contribuição na taxa de mortalidade geral. Na Enseada das Palmas, a máxima densidade de enterococos estimada pelo modelo foi de 1,21 UFC/100mL, no verão. Simulações de dispersão de enterococos mostraram que as regiões mais internas da enseada possuem correntes fracas que não favorecem uma grande dispersão de poluentes para fora da enseada. Os enterococos não tiveram sua taxa de mortalidade correlacionada com a salinidade (r = -0,02), porém a temperatura (r = 0,75) e a radiação solar parecem ter grande influência no seu decaimento. Com exceção do ponto no Saco da Ribeira, que apresentou concentrações de coliformes acima de 1000 NMP/100mL, em geral, as águas mantiveram condições adequadas de balneabilidade nas duas enseadas. Pode-se afirmar que o sistema de correntes na área de estudo, determinado pela geomorfologia da região, não confere alta capacidade de diluição e dispersão de efluentes nas enseadas. Todavia, a circulação marinha atuante e os processos envolvidos no decaimento dos poluentes são suficientes para difundir e diminuir suas concentrações ao longo das enseadas. Concluiu-se que a modelagem ambiental reproduziu de maneira satisfatória os processos envolvidos no transporte e na difusão de poluentes na água do mar, contribuindo com os estudos sobre os efeitos das atividades humanas no sistema costeiro de Ubatuba.
The region of Ubatuba, being a place of tourist attraction, is influenced by human activities that modify some features of water bodies due to the dumping of sewage, the discharge of pollutants and heavy boat traffic. The objective of this study was to evaluate the effects of human activities on the coastal system of Ubatuba through the study of transport processes and diffusion of pollutants, through models that describe the mechanisms and reactions involved in the dispersion of petroleum hydrocarbon (PAHs) and microbiological indicators (thermotolerant coliforms and enterococci) in seawater. The modules of the environmental modeling system Delft3D were used in the study. The hydrodynamic module was implemented in a numerical grid covering the continental shelf adjacent to the north coast of São Paulo. From the analysis and validation of the results of the hydrodynamic module, it was concluded that the model satisfactorily reproduced the marine circulation in the region (Skill values between 0,67 and 1,00).The association of pollution data with the results of hydrodynamic allowed studying the pollutant dispersion mechanisms in Flamengo Bay and in Palmas Bay through the water quality module. The concentration of coliform calculated by the model reached the maximum of 1850 MPN/100mL in the Flamengo Bay, in summer; in the case of PAHs, the maximum level was 0,92 µg/L. The internal parts of the Flamengo Bay have the circulation of water reduced as well as the dispersion of pollutants. The results suggest that the PAHs concentrations were less decay over time, which is probably due to the regional characteristics, such as low hydrodynamic and low nutrient content, which hamper the hydrocarbon degradation processes. On the other hand, the results indicate a considerable decay in bacterial density. Thermotolerant coliform mortality rates had high positive correlation with salinity and temperature (r = 0,94 e r = 0,99, respectively), and the mortality rates due to solar radiation had a good contribution to the overall mortality rate. In the Palmas Bay, the maximum enterococci density estimated by the model was 1,21 CFU/100mL in the summer. Enterococci dispersion simulations showed that the internal regions of the bay have weak currents that do not contribute to a large dispersion of pollutants out of the bay. Enterococci have not had their mortality rate correlated with salinity (r = - 0,02), but the temperature (r = 0,75) and solar radiation seem to have large influence on its decay. With the exception of the point at the Saco da Ribeira, which obtained coliform concentrations above 1000 NMP/100mL, in general, the waters maintained suitable conditions for bathing in the two bays. It can be said that the current system in the study area, determined by the geomorphology of the region, does not provide high capacity for dilution and dispersion of effluents in the bays. However, the marine circulation and the processes involved in the decay of the pollutants are enough to spread and reduce their concentrations along the bays. It was concluded that environmental modeling reproduced satisfactorily the processes involved in the transport and diffusion of pollutants in seawater, contributing to the studies on the effects of human activities on the coastal system of Ubatuba.

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43

Heller, Winfried. "Hydrodynamische Effekte unter besonderer Berücksichtigung der Wasserqualität und ihre Messverfahren." Doctoral thesis, Technische Universität Dresden, 2005. https://tud.qucosa.de/id/qucosa%3A24669.

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Анотація:

The development of fluid mechanics during the twentieth century has been affected by intense research in order to fathom numerous practically relevant hydrodynamic effects, to understand the physical processes and correlations and to describe them mathematically. This became necessary because employing only the fundamental hydrodynamic equations, the description of certain phenomena in fluid flows caused by fluid properties was impossible. In order to assess the quality of fluids regarding their gas contents and their nuclei distributions, various measuring methods and devices have been developed and constructed since the beginning of the twentieth century. This historical development could be described nearly completely in this work, particularly the development of devices to determine the total gas content. Apart from the mostly difficult handling of these measurement methods and devices, only the influence of single parameters such as the total gas content, the dissolved oxygen content, nucleus content, nucleus distribution and the distribution of nucleus sizes on hydrodynamic effects was examined. However, the correlations between these single parameters, as they occur in real flows, could not be taken into consideration. As early as the end of the ninetieth century the development of methods and devices began to determine the tensile strength of fluids. The initially static methods have been followed by the developments of dynamic methods since the beginning of the 1970s. While for specially prepared fluids, tensile strengths of several hundred bar were measured under static conditions, the typical values for water, measured with the eddy and swirl nozzle, range between zero and two bar. This illustrates the strong influence of interactions between all parameters on the tensile strength in flowing fluids. Except for sound velocity and pressure distribution at profiles, water quality particularly affects certain cavitation phenomena. Various cavitation tests around the world have shown that without determining the actual tensile strength of the test water, it is impossible to obtain reproducible results regarding cavitation inception. In experiments concerning cavitation erosion, the correlation between water quality, erosive aggressiveness and erosion rate was proven unmistakably. Evidently, permanent measurement of the test fluid?s tensile stress during cavitation experiments with model bodies is compulsory in order to be able to interpret measurement results correctly. Cavitation phenomena at profiles or other parts affected by flow cause changes of lift, drag and loss coefficients depending on the degree of the cavitation progress. The influence of transition, detachment, obstruction and pressure distribution plays a special role. The quality of electrically conductive fluids is determined by their conductivity. By means of electromagnetic fields Lorentz-forces are generated, whose effect can be observed in lessening of flow detachment, drag reduction and increased lift. Manifold experimental research results in the area of fluid mechanics have proven that the fluid quality must be taken into account when describing real flow processes. Since the many flow parameters are subject to permanent interaction, ultimately, the sum of all single parameters lead to the effects mentioned. For the determination of the water quality such as in cavitation experiments, the tensile stress of the water can be measured making the mathematical description of cavitation inception possible.
Die Entwicklung der Strömungsmechanik im 20. Jahrhundert wurde auch durch intensive Forschungen geprägt, um die zahlreichen in der Praxis auftretenden hydrodynamischen Effekte zu ergründen, die physikalischen Abläufe und Zusammenhänge zu verstehen und diese mathematisch zu beschreiben. Dies wurde notwendig, da mit den hydrodynamischen Grundgleichungen allein keine Beschreibung der aus den Fluideigenschaften resultierenden Erscheinungen in Flüssigkeitsströmungen möglich war. Um die Qualität der Flüssigkeiten bezüglich ihres Gasgehaltes und ihrer Keimverteilung beurteilen zu können, wurden mit Beginn des 20. Jahrhunderts unterschiedliche Messmethoden und Apparaturen entwickelt und gebaut. Diese Entwicklung ließ sich annähernd vollständig darstellen, hierbei besonders die Entwicklungen von Apparaturen zur Bestimmung des Gesamtgasgehaltes. Neben der zumeist schwierigen Handhabung dieser Messgeräte und Methoden wird dabei nur der Einfluss einzelner Messgrößen, wie Gesamtgasgehalt, Gelöstsauerstoffgehalt, Keimgehalt, Keimverteilung und Keimgrößenverteilung auf hydrodynamische Effekte untersucht. Die aber in realen Strömungen auftretenden Wechselwirkungen zwischen den Einflussgrößen werden nicht berücksichtigt. Schon am Ende des 19. Jahrhundert begann die Entwicklung von Geräten und Methoden zur Bestimmung von Zugspannungen in Flüssigkeiten. Den anfänglich statischen Methoden folgten mit Beginn der 70er Jahre des 20. Jahrhunderts die bis heute andauernden Entwicklungen dynamischer Methoden. Während für speziell behandelte Flüssigkeiten unter statischen Bedingungen Zugspannungen von einigen hundert bar gemessen wurden, liegen die typischen Werte für Wasser mit der Wirbel- oder Dralldüse gemessen, zwischen null und zwei bar. Das zeigt den starken Einfluss der Wechselwirkungen aller Einflussgrößen auf die Zugspannung in strömenden Flüssigkeiten. Außer auf die Schallgeschwindigkeit und die Druckverteilung an Profilen hat die Wasserqualität einen besonders starken Einfluss auf bestimmte Kavitationserscheinungen. Weltweite Kavitationstests zeigten, dass ohne Bestimmung der aktuellen Zugspannung des Testwassers keine reproduzierbaren Ergebnisse bezüglich des Kavitationsbeginns möglich sind. Bei Untersuchungen zur Kavitationserosion wurde der Zusammenhang zwischen Wasserqualität und erosiver Aggressivität und Erosionsrate eindeutig nachgewiesen. Die permanente Messung der Zugspannung der Testflüssigkeit ist bei Kavitationsexperimenten an Modellkörpern offensichtlich zwingend notwendig, um die Messergebnisse korrekt interpretieren zu können. Kavitationserscheinungen an Profilen oder Durchströmteilen bewirken Änderungen von Auftriebs-, Widerstands- und Verlustbeiwerten in Abhängigkeit vom Fortschrittsgrad der Kavitation. Hierbei spielen die Beeinflussung der Transition, Ablösung, Versperrung und Druckverteilung eine besondere Rolle. Bei elektrisch leitfähigen Fluiden ist die Qualität durch die Leitfähigkeit bestimmt. Mittels elektromagnetischer Felder werden Lorentzkräfte erzeugt, deren Wirkung sich zeigt in der Unterdrückung von Strömungsablösung, Widerstandsverringerung und stärkerem Auftrieb. Vielfältige experimentelle Forschungsergebnisse auf dem Gebiet der Strömungsmechanik haben gezeigt, dass für die Beschreibung realer Strömungsvorgänge die Qualität des Fluides berücksichtigt werden muss. Da die vielen Einflussgrößen in der Strömung permanenten Wechselwirkungen unterliegen, führt letztlich die Summe aller Einzeleinflüsse auf die genannten Effekte. Für die Bestimmung der Wasserqualität z.B. bei Kavitationsexperimenten kann die Zugspannung des Testwassers gemessen werden, wodurch die genauere mathematische Beschreibung des Kavitationsbeginns möglich wird. - (Diese Arbeit liegt auch in englischer Sprache unter dem Titel "Hydro-dynamic effects with particular consideration of water quality an their measurement methods" in elektronischer Form vor - http://hsss.slub-dresden.de/hsss/servlet/hsss.urlmapping.MappingServlet?id=1141217614058-7645)

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44

Williams, Nicholas Trevor. "Modeling Dissolved Oxygen in Lake Powell using CE-QUAL-W2." BYU ScholarsArchive, 2007. https://scholarsarchive.byu.edu/etd/849.

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Water quality models in the Colorado River Basin have been developed for the basin, river, and individual reservoirs. They are used to support water quality programs within the basin. The models are periodically reviewed and updated to improve the accuracy of simulations. Improving the usefulness of the Lake Powell model, one of the key reservoirs in the basin, is the subject of this study. Lake Powell is simulated using a hydrodynamic and water quality model, CE-QUAL-W2. Previously the model has been used at Lake Powell to simulate hydrodynamics, temperature, and total dissolved solids with a reasonable degree of accuracy. An additional parameter, dissolved oxygen, will be added to the simulations and then calibrated with observed data to verify accuracy. Dissolved oxygen distributions in Lake Powell vary seasonally and change under different hydrologic cycles. They are a function of physical, biological, and chemical processes. Few measurements of these processes in Lake Powell exist. To compensate for the lack of data an empirical method of loading oxygen demand to the model is developed and tested. Observed limnological processes in the reservoir guide the development of the empirical methods. The methods are then tested in 16 year model simulations and compared with dissolved oxygen measurements from the 16 year period. By accurately reproducing the dissolved oxygen distributions the Lake Powell model will have improved accuracy and also broaden its usefulness.

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45

Sousa, Edson Pereira de. "Avaliação de mecanismos dispersivos em rios através de problemas inversos." Universidade do Estado do Rio de Janeiro, 2009. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=892.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
Nesta dissertação é apresentada a avaliação da dispersão de contaminantes no Rio São Pedro, pequeno curso situado na Bacia Hidrográfica do Rio Macaé, centro-norte do Estado do Rio de Janeiro. Para tanto, utilizou-se uma abordagem que conjugou simulação e observação. A simulação compreendeu a modelagem do transporte de substância conservativa em um dado trecho desse rio. O modelo adotado utilizou a formulação unidimensional da equação de advecção-dispersão, que tem como parâmetro crítico o coeficiente de dispersão longitudinal. Paralelamente foi conduzido um experimento de campo, que constou da injeção instantânea de massa conhecida de sal nesse trecho do rio, tendo sido monitorada a concentração resultante em uma seção situada a jusante do ponto de lançamento. Códigos numéricos foram implementados para obter-se o melhor ajuste entre simulação e observação, ajuste esse obtido através da estimativa do coeficiente de dispersão.
In this dissertation we performed an assessment of contaminat dispersion in a small river located at Macaé Watershed Basin. We adopted an approach that made use both of simulation and experiments. The simulation solved the one dimensional transport model for a conservative substance, on which the dispersion coefficient plays a critical role. The observation data was obtained in an experiment especially designed for this purpose. An instantaneous injection of a known quantity of mass of salt in a given position of the river was discharged and the resulting concentration was monitored in two downstream stations. Numerical codes were built in order to obtain a better fitting between simulation and observation.

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46

Jouanneau, Nicolas. "Caractérisation de la dispersion de traceurs passifs dans un écoulement côtier soumis à un régime macrotidal : Étude d'impact de la dynamique sur la qualité de l'eau le long du littoral du Nord-Pas de Calais et de la Picardie." Phd thesis, Université du Littoral Côte d'Opale, 2013. http://tel.archives-ouvertes.fr/tel-00981658.

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Caractériser la circulation et l'évolution de la qualité des eaux côtières en Manche orientale est un enjeu majeur pour de multiples applications dans une région riche en bio-diversité et en ressources halieutiques. L'hydrodynamisme, dominé par un régime megatidal, joue un rôle essentiel dans les processus de dispersion et de mélange le long du littoral du Nord-Pas-de-Calais. La physionomie en "entonnoir" de la Manche orientale donne lieu à une dyssimétrie de l'onde de marée qui induit un flot plus intense et plus bref que le jusant, engendrant une dérive résiduelle vers la mer du Nord accentuée par les vents dominants de sud-ouest. Ce contexte atypique confère une structure complexe à l'écoulement côtier, dans une région dite "à influence d'eau douce". L'utilisation du modèle hydrodynamique MARS3D a permis de mettre en évidence certains phénomènes complexes à l'échelle régionale et comprendre la gense et la dynamique du fleuve côtier. Grâce à la modélisation haute résolution, à l'échelle dite locale, la circulation dans l'enceinte du port de Boulogne-sur-Mer a pu être caractérisée. Il a été démontré qu'un tourbillon anti-cyclonique, caractéristique du régime de flot, permet une évacuation rapide des traceurs passifs transitant par le port. Lors du jusant, une dérive intense vers le sud piège les traceurs dans le port. Ce piégeage peut être accentué ou atténué selon le sens du vent ou le débit fluvial. Une étude de modifications morphologiques de la rade a été réalisée afin de montrer l'utilité de la modélisation pour proposer des solutions innovantes pouvant améliorer la qualité de l'eau. Un travail similaire a été mené en baie de Somme pour comprendre les problèmes relatifs à la qualité de l'eau. Certaines activités sont soupçonnées d'être à l'origine de contamination microbienne et en particulier les moutons de pré-salés, accusés de contribuer majoritairement à l'apport en E. Coli. En assimilant les traceurs passifs au matériel bactérien, nous avons pu appréhender la problématique de la qualité de l'eau. Notre étude a permis de mettre en exergue les conditions environnementales propices à la rétention ou à l'évacuation de matières contaminantes émises par de nombreuses sources alimentant la baie. La convergence des courants, et l'accumulation du matériel contaminant, ont été révélées au voisinage du Crotoyce qui peut expliquer en partie, la qualité médiocre de ces eaux. Ces schémas de circulation interne à la baie de Sommesuivant les conditions environnementales contribue à améliorer les études sur la qualité de l'eau et les futurs aménagements côtiers durables.

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47

Gramotnev, Galina. "Analysis of dispersion and propagation of fine and ultra fine particle aerosols from a busy road." Queensland University of Technology, 2007. http://eprints.qut.edu.au/16338/.

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Nano-particle aerosols are one of the major types of air pollutants in the urban indoor and outdoor environments. Therefore, determination of mechanisms of formation, dispersion, evolution, and transformation of combustion aerosols near the major source of this type of air pollution - busy roads and road networks - is one of the most essential and urgent goals. This Thesis addresses this particular direction of research by filling in gaps in the existing physical understanding of aerosol behaviour and evolution. The applicability of the Gaussian plume model to combustion aerosols near busy roads is discussed and used for the numerical analysis of aerosol dispersion. New methods of determination of emission factors from the average fleet on a road and from different types of vehicles are developed. Strong and fast evolution processes in combustion aerosols near busy roads are discovered experimentally, interpreted, modelled, and statistically analysed. A new major mechanism of aerosol evolution based on the intensive thermal fragmentation of nano-particles is proposed, discussed and modelled. A comprehensive interpretation of mutual transformations of particle modes, a strong maximum of the total number concentration at an optimal distance from the road, increase of the proportion of small nano-particles far from the road is suggested. Modelling of the new mechanism is developed on the basis of the theory of turbulent diffusion, kinetic equations, and theory of stochastic evaporation/degradation processes. Several new powerful statistical methods of analysis are developed for comprehensive data analysis in the presence of strong turbulent mixing and stochastic fluctuations of environmental factors and parameters. These methods are based upon the moving average approach, multi-variate and canonical correlation analyses. As a result, an important new physical insight into the relationships/interactions between particle modes, atmospheric parameters and traffic conditions is presented. In particular, a new definition of particle modes as groups of particles with similar diameters, characterised by strong mutual correlations, is introduced. Likely sources of different particle modes near a busy road are identified and investigated. Strong anti-correlations between some of the particle modes are discovered and interpreted using the derived fragmentation theorem. The results obtained in this thesis will be important for accurate prediction of aerosol pollution levels in the outdoor and indoor environments, for the reliable determination of human exposure and impact of transport emissions on the environment on local and possibly global scales. This work will also be important for the development of reliable and scientifically-based national and international standards for nano-particle emissions.

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48

Claro, Barreto Alejandro. "Expérimentation et modélisation de l'hydrodynamique et de la dispersion de la pollution particulaire au sein des déversoirs latéraux." Thesis, Lyon, 2020. http://www.theses.fr/2020LYSEI083.

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Les déversoirs d’orages (DO) d’un système de collecte sont la principale source de pollution des milieux récepteurs en temps de pluie. La maîtrise des flux de pollution déversés par ces DO requiert l’étude de l’hydrodynamique et du transport de polluants véhiculés généralement sous forme particulaire en suspension. L’ensemble des travaux expérimentaux et numériques s’est intéressé à l’hydrodynamique et à la dispersion des polluants particulaires au niveau des déversoirs latéraux aux échelles laboratoire et terrain. L’écoulement tridimensionnel est caractérisé grâce aux données suivantes : la hauteur d’eau, le débit, le champ de vitesse et l’énergie cinétique turbulente. La dispersion des polluants particulaires est étudiée à l’aide de la répartition massique à l’échelle pilote et de la concentration et du flux de pollution en DBO5 déversés à l’échelle terrain. Cette étude a permis de valider pour la première fois, à notre connaissance, l’approche numérique 3D basée sur la mécanique des fluides numérique (CFD, en anglais) appliquée au cas d’un déversoir latéral complexe soumis à l’autosurveillance réglementaire grâce aux données in situ de hauteurs d’eau, débits amont et débits déversés, collectées par Valence Romans Agglo. Les résultats d’analyse des premières campagnes montrent que le critère de conformité réglementaire lié au flux de pollution déversé en temps de pluie s’avère être adapté au fonctionnement du système de collecte de la ville de Valence. En effet, la concentration en DBO5 déversée par le principal DO est inférieure à celle mesurée en entrée de la station de traitement. Ces travaux confirment l’emploi de l’approche CFD et des essais en laboratoire comme outils opérationnels permettant (i) de comprendre le comportement hydrodynamique d’un DO en temps de pluie, (ii) d’analyser la conformité d’un système de collecte et (iii) d’évaluer et d’améliorer la mise en place de l’autosurveillance
Combined sewer overflows (CSO) in a sewer system are the main source of pollution for the receiving environments during wet weather. The control of pollution flux discharges by CSO requires the study of hydraulics and pollutant transport, conveyed mostly as suspended particles. All experimental and numerical simulations have focused on hydrodynamics and the dispersion of particulate pollutants within side weirs at laboratory and field scales. The tridimensional flow is characterized by means of the water height, flowrate, velocity and turbulent kinetic energy fields. The particulate pollutant dispersion is studied by means of the mass distribution at laboratory scale and the BOD5 concentration and flux discharged at field scale. This study validated for the first time, to our knowledge, the 3D numerical approach based on the computational fluid dynamics (CFD) applied to the case of a complex side weir subjected to regulatory self-monitoring using in situ data of water heights, upstream flows and discharged flows, collected by Valence Romans Agglo. The first campaigns show that the regulatory compliance criterion linked to the flow of pollution discharged in rainy weather is proving to be adapted to the functioning of the sewer system of the city of Valence. Indeed, the concentration of DBO5 discharged by the main CSO is lower than that measured at the entrance of the wastewater treatment plant. This work confirms the use of CFD and laboratory tests as operational tools allowing (i) to understand the hydrodynamic behaviour of CSO in wet weather, (ii) to implement self-monitoring and (iii) to analyse sewerage system compliance

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49

Fernandez, Victoria Julia. "Water quality design storms for stormwater hydrodynamic separators." 2008. http://hdl.rutgers.edu/1782.2/rucore10001600001.ETD.17305.

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50

Wu, Chi-Ray, and 吳啟瑞. "A Hydrodynamic and Water Quality Model for Danshuei River System." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/86843298753435589462.

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博士
國立臺灣大學
生物環境系統工程學研究所
94
Taiwan is an island which the discharge in most rivers flowing enters the ocean. The tidal river is the way of substantial exchange between river and ocean. Fresh water polluted by point and non-point sources from drainage areas concentrated in the tidal river and induced environment and ecology problems. The field surveys on Tanshui River were conducted to investigate the hydraulic and water quality in the processes of substantial exchange of the tidal river. Tanshui River, the largest tidal river in Taiwan, is the study site in this study. A hydraulic and water quality numerical model for Tanshui River, which consists of tributaries, division channel and confluences, has been developed to simulate the detailed variation of the hydraulic and water quality. Several study cases were examined to verify the rationality and accuracy. The result shows that the proposed model can be used to simulate the hydraulic and water quality for the tidal river. The field surveys including salt, temperature, suspended solids, chlorophyll and dissolved oxygen on Tanshui River were carried out from 2002 to 2004. Those field data were used for model calibration and verification. It reveals that the simulation results of the hydraulic and water quality were good agreement with observed values. The present model can provide satisfactory and reliable results of hydraulic and water quality for the tidal river.

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Дисертації з теми "Qualityof hydrodynamics"

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