Dissertations / Theses on the topic 'Hydraulic management'
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Thai, Do Hoang. "Energy Management of Parallel Hydraulic Hybrid Wheel Loader." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-246097.
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Hybridization of driveline system is one possible solution to increase fuel eciency.In this thesis a parallel hybrid hydraulic wheel loader concept was studied. A highpressure accumulator was added to the system and acted as a second source of energy.By adding the high pressure accumulator, regenerative braking energy canbe stored for later utilization. A backward facing simulation model was developedwhere the high pressure accumulator's State Of Charge (SOC) as state variableand hydraulic pump/motor's displacement as control input. Furthermore, dierentenergy management strategies: Dynamic Programming (DP), rule-based andEquivalent Consumption Minimization Strategy (ECMS) were developed. Thesestrategies were evaluated and compared to each other all with respect to the fuelconsumption. The result from conventional machine acted as the benchmark forother strategies to compare with. From simulation results, rule-based strategiesshowed to be the most robust, resulted in lower fuel consumption in every testeddriving cycle. For ECMS, the performance varied from cycle to cycle. A reductionin fuel consumption was observed for short-loading cycles. Especially in one cycle,ECMS result outclassed rule-based and was almost the same as DP. However, asmall increment was observed for long-carry cycle. Here the introduction of lock-upfeature in the torque converter yielded instead the most fuel saving. These valuableconclusions acted perfectly as a good starting point for future product development.Hybridisering av drivlinan är en möjliga lösning för ökad bränsleeffektivitet. En par-allell hybrid hydraulik hjullastare koncept undersöktes i detta arbetet. Genom att sätta en extra högtrycksackumulator till systemet kunde regenerativ bromsningsenergi lagras för senare användning. En bakåt simuleringsmodell med ackumulators laddningstillstånd som tillståndsvariabel och hydraulisk pumps/motors förflyttning som reglering signal utvecklades tillsammans med olika energy regleringstrategier så som: dynamisk programmering (DP), regelbaserad (RB) och Ekvivalent Konsumtion Minimering Strategi (engelska ECMS). Strategierna evaluerades och jämfördes med hänsyn till bränsleförbrukningen där resultaten från konventionella maskinen användes som referens. Regelbaserad strategier visades vara mest robusta där bränsleförbrukning minskades för alla testade körcyklar. För ECMS varierades resultatet mellan olika körcyklar. En minskning av bränsle förbrukning noterades for alla kortcyklar. För en cykel utklassade ECMS RB och var nästan lika bra som DP. För långcyklar resulterade ECMS i en liten ökning av bränsleförbrukning. Att introducera ”låsa-in” funktion i momentomvandlare gavs den störta bränsleminskningen.Slutsatserna var mycket värdefulla till framtidens utveckling.
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Wang, Jian. "Aircraft hydraulic power system diagnostic, prognostics and health management." Thesis, Cranfield University, 2012. http://dspace.lib.cranfield.ac.uk/handle/1826/7424.
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This Individual Research Project (IRP) is the extension research to the group design project (GDP) work which the author has participated in his Msc programme. The GDP objective is to complete the conceptual design of a 200-seat, flying wing civil airliner—FW-11. The next generation aircraft design demands higher reliability, safety and maintainability.
With the development of the vehicle hydraulic system technology, the equipment and systems become more and more complex, their reliability and maintenance become more difficult for designers, manufacturers and customers. To improve the mission reliability and reduce life cycle cost, there is strong demand for the application of health management technology into airframe system design.
In this research, the author introduced diagnostic, prognostic and health management (DPHM) concept into the aircraft hydraulic power system development. As a brand new technology, it is a challenge to apply the DPHM techniques to on-board system. Firstly, an assumed hydraulic power system was designed for FW-11 by the author and used as the case in his IRP research. Then the crucial components and key parameters needed to be monitored were obtained based on Function Hazard Analysis and Failure Modes Effects Analysis of this system. The writer compared a few diagnostic and prognostic methods in detail, and then selected suitable ones for a hydraulic power system. A diagnostic process was applied to the hydraulic power system using a Case-based reasoning (CBR) approach, whilst a hybrid prognostic method was suggested for the system. After that, a diagnostic, prognostic and health management (DPHM) architecture of the hydraulic power system was designed at system level based on the diagnostic and prognostic research. The whole research work provided a general and practical instruction for hydraulic system design by means of DPHM application.
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Dsouza, Serena Karen. "Asset management of offshore oil and gas installations." Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/49282/.
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The UK sector of the North Sea is a mature oil and gas basin subjected to some of the harshest offshore environments with a majority of the oil and gas installations approaching or having exceeded their original design life, often specified as 25 years. It is likely that the operation of these installations will continue for a substantial period in the foreseeable future. However, the ageing nature of these installations present significant challenges to the delivery of high standards of health and safety required by the UK Health and Safety Executive. The issue of ageing installations has been shown to be an important factor in offshore incidents and accidents, leading to an increased risk of accidental loss of hydrocarbon and failures due to equipment deterioration. Two major hazards resulting from ignition of accidental hydrocarbon release are fires and explosions. Failure to minimise the effects of fires and explosions can bring about significant damage to the structural integrity of offshore installations and pose a risk to personnel safety as evidenced by the 1988 Piper Alpha Disaster and the 2010 Deepwater Horizon Explosion and Oil Spill. This thesis presents a practical tool that can be used to predict the costs, risks and service reliability of any given asset management policy for an offshore oil and gas installation. The tool is implemented using a standard Petri Net technique with already adopted and newly proposed high level extensions, and fluid flow modelling technique. The tool is further divided into two sub models that work in conjunction with one another: (1) the Petri Net based Offshore Safety System Degradation and Maintenance Model and (2) the Offshore Fire and Explosion Model based on fluid flow modelling techniques. The aim of the Offshore Safety System Degradation and Maintenance Model is to concurrently simulate the degradation, failure, inspection and maintenance of four safety systems which includes the fire and gas detection system, process isolation, process blowdown, and the deluge system. Simulation of the model generates a variety of statistics such as the estimated operational costs and unavailability associated with implementing any given asset management policy. The Offshore Fire and Explosion Model is then used to model the occurrence of a hydrocarbon leak from a process vessel located within three enclosed modules; wellhead, separation and compression, of an offshore installation. The aim of this model is to predict the frequencies of fires and explosions in the event that the safety systems previously modelled in the Offshore Safety System Degradation and Maintenance Model fail to function on demand in the presence of an ignition source. The model utilises fluid flow modelling to calculate parameters such as the hydrocarbon discharge rate, gas cloud build-up and dispersion, oil-pool build-up and reduction. These parameters can then be used to predict the magnitude of the fires and explosions in terms of the flame length produced in the event of a fire and the overpressures generated in the event of an explosion. The results and statistics generated are highly beneficial to offshore asset operations managers as they can be used to predict the number of maintenance interventions necessary to ensure safety systems are in an acceptable condition. From this, associated costs can be determined enabling offshore managers to allocate resources and budget accordingly. Finally, an optimisation study is carried out using Genetic Algorithm to identify the optimum inspection, maintenance and repair strategy for the offshore safety systems with an acceptable risk level. The methodology presented in this research considers the offshore safety systems and the processes described above in more detail compared to previous literature associated with asset management offshore oil and gas installation. Additionally, the research demonstrates the suitability of Petri Nets for integrating fire and explosion modelling within the asset management framework which is first of its kind. The model can be successfully used to predict costs, risks and service reliability, and to support asset management decisions when the model is implemented in an optimisation framework.
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Mehta, Neha Ph D. Massachusetts Institute of Technology. "Water management in hydraulic fracturing-a planning and decision optimization platform." Thesis, Massachusetts Institute of Technology, 2014. http://hdl.handle.net/1721.1/95585.
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Thesis: S.M. in Technology and Policy, Massachusetts Institute of Technology, Engineering Systems Division, 2014.Cataloged from PDF version of thesis.
Includes bibliographical references (pages 73-78).
Recent developments in hydraulic fracturing technology have enabled cost-effective production of unconventional resources, particularly shale gas in the U.S. The process of hydraulic fracturing is water intensive, requiring 4-7 million gallons of water per well, to which a range of chemicals must also be added in order to produce an effective fracturing fluid. Following a fracturing stimulation, anywhere from 10-40% of the injected volume of the water flows back to the surface as a polluted stream of wastewater. This polluted stream of water and the overall inefficient use of water in the hydraulic fracturing process has resulted in a number of negative environmental consequences, specifically surrounding ground and surface water quality and quantity. In considering how to minimize the environmental impacts of hydraulic fracturing, effectively managing water throughout the entire hydraulic fracturing water cycle (water acquisition and disposal) is obviously critical. This dissertation articulates a GIS based optimization model that has been developed to optimize water management planning for unconventional oil and gas production. The model enables a diverse set of stakeholders to develop customized water management strategies based on the geological characteristics and water infrastructure of any given play. The model comprises of a front end GIS interface and a back end optimization engine, designed to minimize the overall system cost of water handling as well as minimizing the overall water footprint of the system. Altogether, it is a powerful decision making tool, which allows the operators to optimize and analyze the temporal and spatial variations in flowback, and produced water management and provide an operationally convenient method to access and share the model analysis. From a regulatory perspective, the modeling framework provides a comprehensive template for a water management plan and could be used as a basis to develop tailored, customized regional solutions that can incorporate the inherent heterogeneity widespread across today's oil and gas plays.
by Neha Mehta.
S.M. in Technology and Policy
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Hixon, Lee Franklin. "Making the Case for Tailored Stormwater Management." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/46200.
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Protection of downstream channels and reduction in flooding can potentially be improved by evaluating alternative site stormwater management (SWM) strategies at a watershed scale and selecting the optimal strategy for a subject watershed. Tailoring a management strategy for a specific watershed may be worthwhile to minimize development costs and maximize downstream benefit. A hydrologic/hydraulic model for a watershed in Blacksburg, Virginia, is used to evaluate downstream results based on implementation of several alternative SWM strategies currently practiced within the United States.
Results show none of the strategies meet the goal of maintaining the baseline goal at the watershed POI for the full range of design storms. Modification to the strategy that performs best at the watershed scale did meet the watershed goal for all design storms except the 1-year. For smaller storm events, it appears that increasing the volume of an initial capture and the drawdown time to release that volume does not increase performance downstream. This is potentially significant as extra dollars spent on site would not provide extra benefit downstream. When post-development peak runoff rates are detained to the predevelopment rate for larger storm events, whether based on a site or watershed focused strategy, the watershed goal can be met. A volume reduction strategy performs well, but implementation is hindered by soils with poor infiltration and the presence of karst.
Other insight to watershed based management strategies, the role of regional facilities and predevelopment condition assumptions at the site scale to maintain a baseline condition downstream are discussed.Master of Science
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Frick, Peyton M. "A hydraulic actuated thermal management system for large displacement engine cooling systems." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1193080466/.
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Krüßmann, Martin, and Karin Tischler. "Complexity Management to design and produce customerspecific hydraulic controls for mobile applications." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200692.
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Complexity management is the key to success for mobile machinery where the variety of customers and applications requires individual solutions. This paper presents the way Bosch Rexroth supports each OEM with hydraulic controls – from specification and conception towards application and production. It gives examples how platforms and processes are optimized according to the customer needs. The demand for flexible, short-term deliveries is met by an agile production with the technologies of Industry 4.0.
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He, Jiajie Dougherty Mark Lange Clifford R. "Hydraulic management of SDI wastewater dispersal in an Alabama Black Belt soil." Auburn, Ala., 2009. http://hdl.handle.net/10415/1973.
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Burrows, Mark Robert. "Landfill hydrogeology and the hydraulic properties of in situ landfilled material." Thesis, Royal Holloway, University of London, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.286066.
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Klein, Michael. "Hydraulic fracturing and shale gas extraction." Kansas State University, 2012. http://hdl.handle.net/2097/15160.
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Master of ScienceDepartment of Chemical Engineering
James Edgar
In the past decade the technique of horizontal drilling and hydraulic fracturing has been improved so much that it has become a cost effective method to extract natural gas from shale formations deep below the earth’s surface. Natural gas extraction has boomed in the past few years in the United States, enough that it has driven prices to an all time low. The amount of natural gas reserves in the U.S. has led to claims that it can lead the country to energy independence. It has also been touted as a cleaner fuel for electricity generation and to power vehicles. This report explains hydraulic fracturing and horizontal drilling particularly with regards to utilizing the techniques for natural gas extraction from shale gas. It also discusses the environmental impact due to the drilling and gas extraction. It demonstrates that although the natural gas beneath the U.S. is a valuable resource, the impacts to the planet and mankind are not to be taken lightly. There is the potential for the effects to be long term and detrimental if measures are not taken now to control them. In addition although on the surface natural gas seems to be a greener fuel, particularly in comparison to gasoline, it is also considered worse for the environment.
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Pulitzer, Seward Webb 1974. "Feasibility assessment and design of micro hydraulic solid-state transducers." Thesis, Massachusetts Institute of Technology, 1998. http://hdl.handle.net/1721.1/9064.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1998.Includes bibliographical references (p. 179-184).
The performance of a number of mechanical applications could be greatly improved by the introduction of transducers that are capable of exploiting the inherent power densities of piezoelectric materials. The ability of these solid-state materials to exert large forces at high frequencies engenders them with specific power levels (mass normalized) that are often several orders of magnitude greater than conventional transducers, but their utility is offset by their small achievable strains. A novel concept for a device capable of improved solid-state transduction, Micro Hydraulic Solid-State Transducers (MHSTs), is introduced and explored in this thesis. The concept is comprised of two core principles: ( 1) utilization of a hydraulic system consisting of a pump, valves, and a working fluid to rectify the high frequency reciprocations of a piezoelectric drive element into unidirectional motion, and (2) performance enhancement through miniaturization. The goal is a transducer possessing high power densities that is useful in conventional applications. Feasibility of the MHST concept is evaluated by designing, modeling, and simulating a prototype mechanism. The effects of miniattariza~ion on device performance are investigated and an optimal scale is determined. Concept feasibility is based on predicted system performance, existing issues, and manufacturing constraints. It is concluded that the concept is feasible and warrants further development.
by Seward Webb Pulitzer, III.
S.M.
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Swain, Allyson. "Modeling the Groundwater Basin in the Northern Cities Management Area." DigitalCommons@CalPoly, 2021. https://digitalcommons.calpoly.edu/theses/2330.
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A model was developed to simulate the groundwater of 8,300 acres of the Northern Cities Management Area (NCMA), which encompasses the northern portion of the Arroyo Grande Watershed and a small subset of the Santa Maria Valley Groundwater Basin. This watershed and groundwater basin is located on the coast and contains Oceano and the Cities of Arroyo Grande, Grover Beach, Pismo Beach. Groundwater in the NCMA is used heavily for agricultural irrigation in the southern portion and municipal applications in the northern portion. Up to 18 of these municipal wells and over 50 irrigation wells are drawing groundwater at any time. Due to the critical nature of both uses, and location on the coastline, both supply and quality is a significant concern. The objective of this research was to improve an existing groundwater model with a longer model duration, a more detailed and discretized recharge estimation, and incorporation of addition municipal well data. Some data was preprocessed in ArcMap. Groundwater modeling was accomplished with Aquaveo GMS using MODFLOW-NWT upstream weighting package (UPW). Elevation, hydrologic soil conditions, stream gauge heights and flows, recharge rates, fault locations, well locations and pumping rates, and transient head boundaries were created via coverages in GMS and mapped to MODFLOW. The model was calibrated using Parameter Estimation (PEST) with Singular Value Decomposition-Assist (SVD-Assist) to observation data in six select monitoring wells and fifteen Sentry wells. The model showed outflow from the domain to the ocean with groundwater flows shifting to parallel the coast following dry periods and significant simulated drawdown from one particular municipal well. These trends can provide water purveyors in the area with additional information on groundwater trends and effects of pumping rates on formation drawdown.
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Simm, Jonathan. "Direct action self-help groups in UK flood risk management." Thesis, University of Nottingham, 2015. http://eprints.nottingham.ac.uk/29541/.
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This thesis critically evaluates the reasons and extent to which Direct Action Self-Help (DASH) groups are, or can be, viable and an efficacious, efficient and effective means of managing and monitoring Flood and Coastal erosion Risk Management (FCRM) assets. FCRM DASH groups are found to be motivated by challenges of increasing flood risk and reduced public funding, alongside a sense of stewardship and community solidarity, catalysed by a few motivated individuals. The thesis develops a conceptual framework of the different dimensions, contextual aspects and motivations for DASH activity. Case studies show that channel maintenance work by DASH groups can be effective and efficient at reducing some aspects of local fluvial flood risk for lower order flood events. By contrast, maintenance of existing sea walls by DASH groups is less efficient because of the need for significant expenditure on materials and is only efficacious if the engineering is quality controlled; its longer term effectiveness is limited by sea level rise. Professional FCRM coordination and support of DASH activity is examined using a case study of an Environment Agency (EA) area coordinator and comparisons with alternative approaches. Support of DASH groups by FCRM professionals is essential to avoid unwise activity and to provide practical support, seed-corn funding and advice on the nature and extent to which DASH activity might be appropriate. The most effective form of DASH facilitation requires a quality and quantity of involvement that cannot readily be supplied by dispersed arrangements from a number of individuals. The thesis also proposes an approach for assessing and scoring the human dimensions of engineering assets. The dimensions of Sense of Security, Accessibility/Availability and Delight/Inspiration reflect insights from key thinkers from a wide range of disciplines. The framework is verified for the FCRM context and its practicality evaluated by trials in which DASH and other community groups assess human dimensions.
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Pierce, Scott C. (Scott Christopher). "Design and implementation of a quality assurance process for hydraulic elevator installations." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11166.
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Chen, Lopez Jose Choc. "Characterization, Simulation, Analysis and Management of Hydraulic Properties of Greenhouse Plant Growth Substrates." Diss., The University of Arizona, 2011. http://hdl.handle.net/10150/205211.
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The greenhouse industry is facing significant challenges such as the demand for more efficient use of energy and natural resources and prevention of detrimental environmental impacts. Reducing negative environmental impacts can be achieved by utilizing recycled and environmentally friendly products and by optimizing the use of water and root zone substrates. New and advanced root zone substrates are currently tested as substitute for natural soils in greenhouse agriculture. They can be inert non-organic materials such as rockwool and perlite. These are mined products from the earth, and are difficult to dispose after use. Natural substrates such as peat are being consumed faster than being regenerated. A new potential substrate that consists of recycled foamed glass aggregates is considered an alternative, as it is environmentally friendly, non-toxic and disposable. Experiments with foamed glass aggregates and with foamed glass aggregate/coconut coir mixtures indicated that the yield of greenhouse tomatoes was not statistically significant different (α=0.05) when compared to rockwool. To investigate the potential application of recycled glass as a root zone substrate, physical and hydraulic properties were measured. For comparison, the same measurements were completed for rockwool, coconut coir, perlite, and PET/PE fibers as well as for a mixture of coconut coir and recycled glass. The water characteristics (WC) determined for each substrate exhibited distinct air entry potentials, which provided information for irrigation scheduling, water storage and aeration for optimum plant growth conditions. Coconut coir and rockwool exhibited a unimodal shaped water retention curve, while foamed glass aggregates and perlite exhibited bimodal shaped curves. The obtained substrate properties were used as input paramaters for HYDRUS- 2D/3D model to simulate water mass balance and matric potential distributions within a typical growth container of foamed glass aggregates. The simulated matric potential and water content distributions were compared to tensiometer measurements of matric potential in the foamed glass aggregates. The simulations compared favorably with laboratory experiments measured under controlled environmental conditions.
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Abu, Al Faraj Noura. "Improving Leak Detection in Water Distribution Networks through Hydraulic Modeling and Pressure Management." Master's thesis, Temple University Libraries, 2012. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/214800.
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Civil EngineeringM.S.C.E.
Approximately six billion gallons of drinking water are lost through distribution systems every day across the United States. In Philadelphia alone, an estimated 22 million gallons per day (MGD) of water is unaccounted for. This constitutes 25% of drinking water produced each day. Water is lost through distribution networks due to various reasons, such as erroneous meter readings, inaccurate billing, and physical damage to the infrastructure. According to the Philadelphia Water Department's Water Audit, water losses in the year 2010 amounted to over $30 million. Not only does "unaccounted-for water" cost the city of Philadelphia millions of dollars every year, it could also be affecting the quality of our drinking water; undetected leaks could potentially allow pathogens to enter the pipes and contaminate the network's water. This risk is magnified in periods of high flow demands such as during fire emergencies. Currently, the City utilizes many methods for detecting and repairing leaks including acoustic leak detection methods. However, these methods are not fast and not very effective in large diameter pipes. This thesis proposes a method for leak detection that utilizes hydraulic modeling and pressure management in the water distribution network to find the source of leaks as quickly and efficiently as possible causing less water to be wasted. Millions of dollars worth of wasted water could be saved while protecting the quality of our water from contamination.
Temple University--Theses
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Stout, Trinity L. "Development and Application of Hydraulic and Hydrogeologic Models to Better Inform Management Decisions." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6044.
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Water is one of the most important and limited resources in regions with little rainfall. As populations continue to grow, so does the need for water. Individuals in water management positions need to be well informed in order to avoid potential negative effects concerning the overall quality and amount of water available for both people and the environment. In order to provide better information for these individuals, computer models and mathematical relationships are commonly developed to estimate the outcome of different situations regarding surface water and groundwater. Along these lines, this study focused on two modeling studies that provide information to managers regarding either stream restoration techniques or the amount of groundwater available.
The first study investigated the effects that beaver dams have on streams. In order to do this, a computer model was developed to represent a section of stream with beaver dams and a section without. The model provided information regarding changes in the average depth, width, and velocity of the stream as a result of having beaver dams. We also measured changes in sediment size distributions between the two stream sections to confirm that beaver dams additionally impact sediment movement and channel shape. Results indicated that only a few dams are actually needed to achieve many of the desired changes in stream restoration.
The second study involved testing an equation that was used to predict how much precipitation would become groundwater in a Midwestern watershed. Variables in the equation included measurements of natural or developed land, movement of water through soil, the depth of the water table, and hillslope steepness. We tested the equation in two western watersheds to determine if variables used in the earlier study remain relevant when applied under different conditions. The independent application of the method to each western watershed stressed the importance of meeting simplifying assumptions and developing more complete datasets. We also found that the application of existing simplified empirical relationships may not be suitable in estimating groundwater recharge in mountain watersheds.
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Shan, Mingwei. "Modeling and Control Strategy for Series Hydraulic Hybrid Vehicles." University of Toledo / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1260130398.
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Pam, Eugene Dung. "Risk-based framework for ballast water safety management." Thesis, Liverpool John Moores University, 2010. http://researchonline.ljmu.ac.uk/5986/.
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Ballast water has been identified as a major vector for the translocation of Non- Indigenous Invasive Species (NIS) and pathogens across zoogeographical regions and subsequent discharged into recipient port states/regions. This is bound to increase given factors like the globalization of trade and the economy of scale of the ship size. Established NIS has posed significant threat to the human health, economy, finances and marine bio-diversity of recipient regions and port states. The risks associated with the discharged NIS are uncertain and difficult to assess due to the stochastic nature of species assemblages and dispersal mechanism. The safest control measure advocated by the IMO is the conduct of ballast water exchange at sea while appropriate and effective proto-type treatment technologies are being developed and approved for future application. This study has been conducted while recognizing the inability of probabilistic approaches applied in ballast water risk management to addressing uncertainty and inadequacy of data. A qualitative approach using powerful multi-criteria decision making techniques and the safety principles of the Formal Safety Assessment framework have been utilized in this research to develop three generic models for ballast water hazard estimation, risk evaluation and decision-making analysis respectively. The models are capable of being modified and utilized in the industry to address the problems of uncertainty and inadequacy of data in ballast water management. This is particularly useful as an interim measure for port states in developing economies (with insufficient data and technology) to developed robust ballast water management plans. While recognising the huge impact of ballast water pollution in recipient regions this study recommends that ballast water management programmes be given due recognition as an important element of sustainable development programmes at national and international levels. The non-availability of a benchmark based on previous research on which to fully validate the research outcome was identified as a major limitation of this research study. The models developed will therefore be subject to modifications as new data become available.
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Singh, C. R. "Hydrological and hydraulic modelling for the restoration and management of Loktak Lake, Northeast India." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/805119/.
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Loktak Lake is an internationally important wetland in northeast India that provides valuable goods and services to local communities as well as supporting high biodiversity. Over the last three decades ecological modifications have occurred, most notably due to the construction and operation of the Ithai Barrage. The focus on maximising hydropower generation increased mean lake water levels and reduced their annual variability. This thesis synthesises hydrometeorological and related data for the lake and its catchment. Data are employed in coupled hydrological / hydraulic catchment models (MIKE SHE / MIKE 11) of three gauged sub-catchments, which are calibrated / validated using observed discharges. Results are used to estimate ungauged sub-catchment flows. Catchment model results are combined with meteorological data and current abstractions within a water balance model which successfully simulates observed lake water levels. A series of barrage operation options are developed using the water balance model which prioritise the requirements of major stakeholders (hydropower, agriculture, and the lake ecosystem). A final option is developed, which shows that it is possible to balance the demands of these stakeholders. The implications of climate change are assessed by forcing meteorological inputs to the catchment and water balance models based upon a number of climate scenarios. In the majority of these scenarios, river inflows increase resulting in higher lake water levels that could further exacerbate ecological degradation of the lake as well as enhancing flooding of lakeside communities. The elevated water levels may permit additional irrigation abstractions however existing infrastructure limits increases in hydropower generation. The sustainability of the barrage operation options in the face of climate change is assessed. Results suggest that climate change is likely to limit the ability of barrage management to satisfy hydropower and agricultural demands whilst at the same time establishing a more ecologically appropriate lake water level regime.
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Seyoum, Wondwosen. "HYDRAULIC RELATIONSHIPS BETWEEN BURIED VALLEY SEDIMENTS AND ADJACENT BEDROCK FORMATIONS." Kent State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=kent1336439133.
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Migliore, Elizabeth M. "A Case Study of Hydraulic Fracturing in Wetzel County, West Virginia." Ohio University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1375175273.
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Cetinkaya, Oguz Kagan. "Management Of Reservoir Sedimentation Case Studies From Turkey." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/12607016/index.pdf.
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Siltation is becoming a big problem as the dams get older all over the world. Conservation and sustainable management of existing reservoirs is gaining more importance than constructing new dams. In this study the program RESCON, which is outcome of a World Bank sponsored project, has been used to examine sediment removal strategies (flushing, hydrosuction sediment removal, dredging and trucking) for four dams of Turkey namely Çubuk I Dam, Bayindir Dam, ivriz Dam and Borç
ka Dam. Sediment measurements are made by governmental agencies in Turkey. In this study characteristics of these measurements will be presented for the future sediment related studies. Then sediment removal strategies which were used in RESCON will be introduced. Evaluation of RESCON results have been made and compared with previous studies for verification except Borç
ka Dam, since it is under construction.
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Seobi, Tshepiso. "Soil hydraulic properties as influenced by grass and agroforestry contour buffer strips /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p1422964.
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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.
26
Zhang, Shulan. "Soil hydraulic properties and water balance under various soil management regimes on the Loess Plateau, China /." Umeå : Dept. of Forest Ecology, Swedish University of Agricultural Sciences, 2005. http://epsilon.slu.se/2005126.pdf.
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Vereau, Melanie, Jose Rojas, Daniel Aderhold, Carlos Raymundo, and Francisco Dominguez. "Designing a Procurement Management Model to Reduce Project Delays in a Hydraulic and Automation Systems Company." Springer Verlag, 2020. http://hdl.handle.net/10757/656135.
Full textAbstract:
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.This study focuses on the factors that cause project delays in an industrial hydraulic company. More specifically, the article also addresses the development of on-demand engineered products and the impact of the procurement process on delays. As part of the investigation, the authors assessed the historical data of the projects completed in 2017 before determining the critical path for each project in an attempt to identify which project stages may be improved. After further assessing the resulting data, the planning and procurement procedures were deemed as requiring improvement. Next, the article proposes a training plan and new procedures based on the Project Management Body of Knowledge guidelines for Engineer-to-Order projects. In conclusion, the results showed that delays were effectively reduced after implementing these new procedures in both Project Management stages.
28
Reichenwallner, Christopher, and Daniel Wasborg. "Control of a Hydraulic Hybrid System for Wheel Loaders." Thesis, Linköpings universitet, Fluida och mekatroniska system, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-158902.
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In recent years many companies have investigated the use of hybrid technology due to the potential of increasing the driveline’s efficiency and thus reducing fuel consumption. Previous studies show that hydraulic hybrid technology can be favourable to use in construction machinery such as wheel loaders, which often operate in repetitive drive cycles and have high transient power demands. Parallel as well as Series hybrid configurations are both found suitable for wheel loader applications as the hybrid configurations can decrease the dependency on the torque converter. This project has investigated a novel hydraulic hybrid concept which utilizes the wheel loaders auxiliary pump as a supplement to enable both Series and Parallel hybrid operation. Impact of accumulator sizes has also been investigated, for which smaller accumulator sizes resembles a hydrostatic transmission. The hybrid concept has been evaluated by developing a wheel loader simulation model and a control system based on a rule-based energy management strategy. Simulation results indicate improved energy efficiency of up to 18.80 % for the Combined hybrid. Moreover, the accumulator sizes prove to have less impact on the energy efficiency. A hybrid system with decreased accumulator sizes shows improved energy efficiency of up to 16.40 %.
29
Newmiller, Jeanette Eileen. "River Hydraulics on a Steep Slope Can a 2D Model Push the Limits of the Hydrostatic Assumption?" Thesis, University of California, Davis, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10635872.
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The Saint-Venant shallow water equations are commonly used to model river hydraulics. The equations utilize a hydrostatic assumption with a recommendation to limit use to a bed slope less than 1:10, vertical to horizontal. This recommended limit was made in an era when calculations were performed by hand and therefore minimized by performing a one-dimensional analysis with the distance between river stations maximized. Current technology makes a more detailed analysis accessible.
This study investigates the effects of applying a two-dimensional hydraulic model that utilizes the Saint-Venant shallow water equations without correction for non-hydrostatic conditions to a bed slope of 1:8. By doing so it was hoped to show that there exists an effective and economical method for engineers to analyze hydraulic effects in these conditions.
A comparative analysis of the results from the 2D model and a 3D non-hydrostatic model was utilized to investigate the theoretical limit of slope on the hydrostatic assumption. The models consisted of an existing 2D model previously developed for an engineering study and a 3D model developed for this study, which employed a novel approach to approximate the effects of surface roughness. The analysis compared model results for depth, velocity, and flow rate at nine cross sections on the study reach. While the findings from the research are not conclusive they do illustrate that a well resolved 2D model is able to push the 1:10 slope limit on the hydrostatic assumption for the shallow water equations. It was found that a uniform flow applied to the 2D model and allowed to come to steady state maintained a relatively consistent flow rate throughout the length of the reach. This demonstrates that the model did not produce any artificial gains or losses. Surprisingly, the 2D model accomplished this while the 3D model did not.
These findings are important in locations where the accepted methods of 3D non-hydrostatic modeling would be computationally cumbersome and cost prohibitive. The lack of efficient and affordable analysis tools rated for steep slopes leads to the construction of facilities with unknown hydraulic risk to life and property. Fully verifying the methods of this study would provide needed support to hydraulic engineers for these conditions.
Concurrent to the research for this thesis, was the development of a series of lessons on introductory hydraulic engineering for middle school students. Engineering is characterized by its hands on, real world application of science and math and is rooted in a tradition of disseminating knowledge through mentorship. Many engineering topics provide opportunity to spark the minds of our youth. The final chapter of this paper is a summary of this work. It is included it here to encourage more engineers to share their work with the next generation.
30
Wahl, Mark D. "Key Influences on Hydraulic Efficiency in Treatment Wetlands." The Ohio State University, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=osu1385421888.
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Fini, Massimiliano. "Hydraulic modeling of the Panaro river for flood hazard investigation." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2021.
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These days, floods are classified among the major threats that catchments, communities and, indirectly, economies are facing. Due to the unpredictability of nature processes, further enhanced by the effect of Climate Change, flood hazard and risk have to be carefully studied and assessed. Italy has a long history of environmental disasters due to floods, caused by poor catchment management, peculiar catchment morphology and accompanied by high return period hydrological events. This dissertation focuses on the 1D-2D unsteady state flow simulation for a preliminary hazard assessment in the downstream sector of the Panaro River (most downstream right tributary of the Po River). This work aims to expand upon the strategical guidelines identified within the Flood Risk Management Plan outlined for the Po District, a major project AIPO worked on to analyse the feasibility of interventions for the adjustment of the Panaro levee system and finally, to preliminary assess the flood hazard related to a test-site of OPERANDUM. This catchment experienced extreme events, which evolved into socio-economic damage along the plain. Therefore, the first chapter starts by introducing the current National and European flood legislation. It gives an insight of the Panaro defensive system and about the two main tools used in flood risk management: Flood Risk and Flood Hazard maps. The second chapter provides an overview of past flood events in the Panaro River and surroundings. The third chapter briefly illustrates the hydraulic model used, HEC-RAS, and the implementation of both river geometry and boundary conditions. The fourth and fifth chapter cover the aspect related to data availability, data collection and hydraulic model calibration routine. The last chapter explains the findings of the hazard assessment of the study area.
32
Pham, Thi Bich Ngoc. "Decentralizing hydraulic society : Actor responses to institutional arrangements in Vietnam." Doctoral thesis, Linköpings universitet, Tema vatten i natur och samhälle, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-92825.
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Irrigation decentralization has been launched worldwide with high expectations of improved governance, efficiency, and productivity through democratic processes. However, there is widespread recognition that decentralization is, in reality, unlikely to bring about these positive outcomes. Poor implementation is widely blamed for these failures, but the current study argues that this is only partially true. Decentralization is usually treated as a technical way of power transfer that can be evaluated through quantitative indicators. Much attention goes to searching solutions to constraints during implementation while less emphasis is on understanding of contexts, processes and the consequences of institutional changes. The common approach mainly focuses on local water users’ organizations but gives insufficient attention to the cross-level interactions between involved actors, their responses to reforms, and power relationships. This approach answers the question: what should be done, but not: why do constraints/limitations occur and why are such contradictory results obtained? In this way the approach itself diffuses some of the challenges in reality and the root of problems leading to surprise consequences and failures during implementation. In this study, two irrigation systems in Vietnam were selected to examine the emerging decentralization processes, actors’ responses to the institutional changes, as well as the main options, challenges and constraints to decentralization. My ambition is also to further understand why constraints occur and have counterproductive effects. A mixed methods approach combining qualitative and quantitative methods, and cross-case analysis are applied. The database was built systematically, based on previous experience in this field, and participatory fieldwork. Decentralization is regarded as a power-laden process involving not just local organizations, but also state agencies, local authorities at different levels, state irrigation companies (IDMCs), and farmers. The study describes how institutional arrangements for decentralization have effects on the dynamics and relations of power between actors in multi-level governance, resulting in impacts on autonomy, accountability, participation, and incentives of involved actors. The analysis shows that the legal framework and several well-intended efforts for decentralization have been launched. However, outcomes in terms of power transfer and actors’ performance are not those expected. The current institutional arrangements have created major constraints: (i) imbalanced power relations, (ii) new resource allocation mechanisms creating dependency among actors, (iii) passiveness, vested interest and privilege within state agencies and IDMCs, and (iv) free-riding behavior and distrust among farmers. Prevailing conditions defy policy intentions by finding a new version of a centralized power structure at provincial level, in which power of state agencies and IDMCs are reinforced. Unexpected effects emerge on the autonomy, accountability, participation, and incentives of all involved actors. Decentralization of irrigation systems is a complex process, not merely a technical transfer of power. It is hard to achieve even with policy in place. All the complexities and implications of irrigation need to be thoroughly considered, with the dynamics in society included. Evaluations of decentralization based on production and economic terms are not enough. Impacts of institutional arrangements on power relations between actors, on their incentives, maneuver room in multi-level governance, and ability to comprehend and influence processes, need to be assessed thoroughly. Essential roles remain for central government when irrigation management is decentralized.Decentralisering av bevattningsjordbruk har lanserats över hela världen med höga förväntningar på förbättrad styrning, effektivitet och produktivitet genom demokratiska processer. Men det är allmänt erkänt att decentralisering i själva verket knappast är tillräckligt för att åstadkomma dessa positiva resultat. Dåligt genomförande har allmänt fått bära skulden för svårigheterna, men den aktuella studien hävdar att detta bara delvis är sant. Decentralisering behandlas vanligtvis som ett tekniskt sätt för maktöverföring som kan utvärderas genom kvantitativa indikatorer. Mycket uppmärksamhet går då att söka lösningar på begränsningar under genomförandet medan mindre tonvikt ligger på förståelse av sammanhang, processer och konsekvenser av institutionella reformer. Fokus är främst på lokala vattenanvändarnas organisationer så att alltför lite uppmärksamhet riktas till gränsöverskridande samspel mellan berörda aktörer, deras anpassningar till reformer och maktrelationer. Detta tillvägagångssätt svarar på frågan: vad som bör göras, men inte: varför restriktioner/begränsningar uppstår och varför sådana motstridiga resultat uppnås? På så vis skymmer själva tillvägagångssättet några av de utmaningar som i verkligheten utgör grunder för de problem som leder till överraskande konsekvenser och misslyckanden under genomförandet av decentralisering. I denna studie har två bevattningssystem i Vietnam valts ut för att undersöka framväxande decentraliseringsprocesser, aktörernas svar på de institutionella förändringar, liksom de huvudsakliga alternativ, utmaningar och hinder som finns för decentralisering. Min ambition är också att ytterligare förstå varför begränsningar förekommer och har kontraproduktiva effekter. En blandad strategi som kombinerar kvalitativa och kvantitativa metoder används för att studera gemensamma drag i fallstudierna. Databasen byggdes systematiskt, utifrån tidigare erfarenheter på detta område, och deltagande fältarbete. Decentralisering betraktas som en maktrelaterad process som involverar inte bara lokala organisationer, men också statliga myndigheter, lokala myndigheter på olika nivåer, statliga bevattningsbolag (IDMCs), och bönder. Studien beskriver hur institutionella arrangemang för decentralisering har effekter på dynamik och maktförhållanden mellan aktörer inom flernivåstyre, något som resulterar i att autonomi, ansvarsutkrävande, deltagande, och incitament för de berörda aktörerna påverkas. Analysen visar att det rättsliga ramverket och flera välmenande insatser för decentralisering har lanserats. Men utfallet, vare sig i termer av maktöverföring eller aktörernas prestationer, är inte de förväntade. De nuvarande institutionella arrangemangen har skapat stora begränsningar: (i) obalanserade maktförhållanden, (ii) nya resursfördelningmekanismer som leder till nya beroendeformer mellan aktörer, (iii) passivitet, egenintresse och privilegier inom statliga myndigheter och IDMCs, och (iv) snålskjutsbeteende (”free-riding”) och misstro bland jordbrukarna. Rådande förhållanden går emot politiska intentioner genom att en ny version av en centraliserad maktstruktur på provinsiell nivå skapas genom att makten hos statliga myndigheter och IDMCs förstärks. Oväntade effekter uppstår då för autonomi, ansvar, delaktighet och incitament för alla inblandade aktörer. Decentralisering av bevattningssystem är en komplex process, inte bara en teknisk överföring av makt. Den är svår att uppnå även med policy på plats. Alla komplikationer och konsekvenser av bevattning för den dynamik som ingår i samhället måste noga övervägas. Utvärderingar av decentralisering som bygger på produktion och ekonomiska termer är inte tillräckligt. Konsekvenser av institutionella arrangemang för maktrelationer mellan aktörer, för deras incitament, manöverutrymme inom ett flernivåstyre, och förmåga att förstå och påverka processer, måste bedömas noggrant. Viktiga roller återstår för staten när bevattningsjordbruk decentraliseras.
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Reed, Sue. "The non-tidal, navigable Thames : a bank erosion management strategy." Thesis, University of Nottingham, 1999. http://eprints.nottingham.ac.uk/12772/.
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Processes and mechanisms of bank erosion on the non-tidal, navigable River Thames were identified and investigated using site specific monitoring and extensive geomorphic surveys. As a lowland, impounded river the Thames has little potential for bank erosion associated with reach-scale morphological channel adjustments. In fact, erosion is closely related to local conditions at the bank and significant processes and mechanisms include fluvial entrainment, slumping, and weakening and weathering of in situ bank material. Approximately 38.5km of eroding bankline was measured (-10% of the total length). Average rates of bank erosion monitored ranged from 0.05ni/yr to -0.5m/yr. The relative contribution to bank retreat of each process or mechanism depends on local conditions such as the use of the bank, the type of bank material and the bank geometry and the type of vegetation. Analysis of the causes of bank retreat at 147 sites along the River Thames revealed that erosion was generally influenced by a combination of factors. Navigation related activities contribute to the bank erosion at nearly all sites (-90%) but is solely responsible for erosion at only about 12%. Factors related to the use of the bank and adjacent land contribute to erosion along -65% of the total length of eroding bank but are the sole influence at only -5%. Channel planform and geometry contribute to -53% of observed bank erosion, but are the sole influence at less than <1% of the erosion sites. A review of selected of erosion control techniques applied on the River Thames suggested that solutions tend to be over-engineered and that strategies adopted were not necessarily appropriate for the causes and consequences of the bank erosion. Furthermore, whilst mitigation measures are often incorporated into the solutions, environmental enhancements are rarely included. Assessment of the causes and consequences of erosion has led to the development of a bank erosion management strategy for the River Thames based on geomorphological and sustainability principles. The strategy is presented as a transferable tool through which to achieve sustainable river management.
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Mokhtari, Kambiz. "Advanced risk management in offshore terminals and marine ports." Thesis, Liverpool John Moores University, 2011. http://researchonline.ljmu.ac.uk/6094/.
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This research aims to propose a Risk Management (RM) framework and develop a generic risk-based model for dealing with potential hazards and risk factors associated with offshore terminals' and marine ports' operations and management. Hazard identification was conducted through an appropriate literature review of major risk factors of these logistic infrastructures. As a result in the first phase of this research a Fuzzy Analytical Hierarchal Process (FAHP) method was used for determining the relative weights of the risk factors identified via the literature review. This has led to the development of a generic risk -based model which can help related industrial professionals and risk managers assess the risk factors and develop appropriate strategies to take preventive/corrective actions for mitigation purposes, with a view of maintaining efficient offshore terminals' and marine ports' operations and management. In the second phase of the research the developed risk-based model incorporating Fuzzy Set Theory (FST), an Evidential Reasoning (ER) approach and the IDS software were used to evaluate the risk levels of different ports in real situations using a case study. The IDS software based on an ER approach was used to aggregate the previously determined relative weights of the risk factors with the new evaluation results of risk levels for the real ports. The third phase of the research made use of the Cause and Consequence Analysis (CCA) including the Fault Tree Analysis (FTA) and Event Tree Analysis (ETA) under a fuzzy environment, to analyse in detail the most significant risk factors determined from the first phase of the research, using appropriate case-studies. In the fourth phase of the research an individual RM strategy was tailored and implemented on the most significant risk factor identified previously. In the last phase of the research and in order to complete the RM cycle, the best mitigation strategies were introduced and evaluated in the form of ideal solutions for mitigating the identified risk factors. All methods used in this research have quantitative and qualitative nature. Expert judgements carried out for gathering the required information accounted for the majority of data collected. The proposed RM framework can be a useful method for managers and auditors when conducting their RM programmes in the offshore and marine industries. The novelty of this research can help the Quality, Health, Safety, Environment and Security (QHSES) managers, insurers and risk managers in the offshore and marine industries investigate the potential hazards more appropriately if there is uncertainty of data sources. In this research with considering strategic management approaches to RM development the proposed RM framework and risk based model contribute to knowledge by developing and evaluating an effective methodology for future use of the RM professionals.
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Randall, Michael J. "BEST MANAGEMENT PRACTICES EFFECTIVENESS TO REDUCE SEDIMENT TRANSPORT TO MORRO BAY." DigitalCommons@CalPoly, 2012. https://digitalcommons.calpoly.edu/theses/740.
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The Morro Bay Watershed, which is located inSan Luis Obispo County,California, covers more than 48,000 acres of land and discharges intoMorroBaythrough the Morro Bay National Estuary (MBNE). The Chorro Creek Subwatershed consists of approximately 30,000 acres of the overall watershed. The MBNE provides an ecosystem that supports a variety of wildlife from the common sea gull to the endangered sea otter. The estuary is also home to over 200 species of birds. The operational waterfront of theMorroBayHarborwas and continues to be a strong supporter to the local economy of the City of Morro Bay. Numerous studies were conducted since the 1990s throughout the watershed to study the sedimentation of the estuary and bay and identified accelerated erosion and subsequent sedimentation as a major threat to sustainability of the bay. As a result, various Best Management Practices (BMPs) were implemented in the watershed to reduce sediment loading and transport to the bay. Localized evaluations of various BMPs have been performed to investigate effectiveness of individual BMPs. This paper consolidates this information and develops a comprehensive spatially distributed watershed simulation model (1) for detailed understanding of the erosion and sedimentation processes in the watershed; (2) to evaluate a watershed scale effectiveness of the conservation practices that were installed in the watershed; (3) to identify optimal BMP types and sites that may be used in the future to further reduce sedimentation of the bay at minimal cost; (4) to organize and document the various sources of data and studies that have been performed to date in the Chorro Creek subwatershed. Soil and Water Assessment Tool (SWAT) was used to develop the model and to evaluate the pre- and post-BMP implementation characteristics in the subwatershed. Combining the data and efforts of past BMP evaluations, land use, soil type, climate data, and streamflow data, statistical evaluations, and model sensitivity analysis will help build and calibrate a robust SWAT model that can be used to track BMP evaluation efforts, as well as other watershed management tasks. Through the evaluation of BMPs in the watershed, efforts can be made to implement the more successful BMPs in the watershed or in other similar watersheds. Sensitivity analysis was performed using a global sensitivity analysis method and streamflow and sediment yield was calibrated using the Shuffled Complex Evolution-University ofArizona.
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Smemoe, Christopher M. "Floodplain Risk Analysis Using Flood Probability and Annual Exceedance Probability Maps." Diss., CLICK HERE for online access, 2004. http://contentdm.lib.byu.edu/ETD/image/etd379.pdf.
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Demirbas, Korkut. "Optimal Management Of Coastal Aquifers Using Heuristic Algorithms." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613135/index.pdf.
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Excessive pumping in coastal aquifers results in seawater intrusion where optimal and efficient planning is essential. In this study, numerical solution of single potential solution by Strack is combined with genetic algorithm (GA) to find the maximum extraction amount in a coastal aquifer. Seawater intrusion is tracked with the potential value at the extraction well locations. A code is developed by combining GA and a subroutine repeatedly calling MODFLOW as a numerical solver to calculate the potential distribution for different configurations of solution (trial solutions). Potential distributions are used to evaluate the fitness values for GA. The developed model is applied to a previous work by Mantoglou. Another heuristic method, simulated annealing (SA) is utilized to compare the results of GA. Different seawater prevention methods (i.e. injection wells, canals) and decision variables related to those methods (i.e. location of the injection wells or canals) are added to model to further prevent the seawater intrusion and improve the coastal aquifer benefit. A method called &ldquoAlternating Constraints Method&rdquo
is introduced to improve the solution for the cases with variable location. The results show that both proposed method and the regular solution with GA or SA prove to be successful methods for the optimal management of coastal aquifers.
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Zhang, Xi. "SPATIAL ESTIMATION OF HYDRAULIC PROPERTIES IN STRUCTURED SOILS AT THE FIELD SCALE." UKnowledge, 2019. https://uknowledge.uky.edu/pss_etds/117.
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Improving agricultural water management is important for conserving water during dry seasons, using limited water resources in the most efficient way, and minimizing environmental risks (e.g., leaching, surface runoff). The understanding of water movement in different zones of agricultural production fields is crucial to developing an effective irrigation strategy. This work centered on optimizing field water management by characterizing the spatial patterns of soil hydraulic properties. Soil hydraulic conductivity was measured across different zones in a farmer’s field, and its spatial variability was investigated by using geostatistical techniques. Since direct measurement of hydraulic conductivity is time-consuming and arduous, pedo-transfer functions (PTFs) have been developed to estimate hydraulic conductivity indirectly through more easily measurable soil properties. Due to ignoring soil structural information and spatial covariance between soil variables, PTFs often perform unsatisfactorily when field-scale estimations of hydraulic conductivity are needed. The performance of PTFs in estimating hydraulic conductivity in the field was therefore critically evaluated. Due to the presence of structural macro-pores, saturated hydraulic conductivity (Ks) showed high spatial heterogeneity, and this variability was not captured by texture-dominated PTF estimates. However, the general spatial pattern of near-saturated hydraulic conductivity can still be reasonably generated by PTF estimates. Therefore, the hydraulic conductivity maps based on PTF estimates should be evaluated carefully and handled with caution. Recognizing the significant contribution of macro-pores to saturated water flow, PTFs were further improved by including soil macro-porosity and were proven to perform much better in estimating Ks compared with established PTFs tested in this study. Additionally, the spatial relationship between hydraulic conductivity and its potential influencing factors were further quantified by the state-space approach. State-space models outperformed current PTFs and effectively described the spatial characteristics of hydraulic conductivity in the studied field. These findings provided a basis for modeling water/solute transport in the vadose zone, and sitespecific water management.
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Smith, S. Andrew Enticknap, and ANDREW_SMITH@acdi-cida gc ca. "Water First : a political history of hydraulics in Vietnam's Red River Delta." The Australian National University. Research School of Pacific and Asian Studies, 2002. http://thesis.anu.edu.au./public/adt-ANU20050314.135921.
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Between 1961 and 1976 Häi Hung province -- present day Häi Duong and Hung
Yên -- lost the equivalent of two entire districts of agricultural land. How could so
much land be abandoned under a collectivised agriculture system? And what role
did poor water control infrastructure play in creating such a situation?¶
I answer these questions by examining the historical patterns of hydraulic
development in northern Vietnam from the beginning of the 19th century until the
introduction of the Production Contract system in 1981. Underlying both the
French colonial and communist visions of modernity and economic development
was a belief that improving agricultural productivity, of which large-scale hydraulic
infrastructure was an important component, could catalyse growth in the rural
economy, which could then finance industrialisation. I argue throughout this thesis
that developing large-scale hydraulic infrastructure in the Red River delta has relied
upon the creation of a hydraulic bargain between the state and water users. This is
in contrast to Wittfogel's theory of the hydraulic state, insofar as developing
hydraulic infrastructure has depended upon the active political and economic
participation and support of water users, and not the absolute power of the state.
The political economic history of the hydraulic bargain highlights the relative
power of peasants to influence the direction of large-scale hydraulic development
and, as such, the shape of the Red River delta's wet-rice economy.
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Nazari, Saeid. "ASSESSMENT OF WATERSHED NUTRIENT LOADS AND EFFECTIVENESS OF BEST MANAGEMENT PRACTICES." UKnowledge, 2018. https://uknowledge.uky.edu/ce_etds/63.
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Several methods have been developed for use in estimating the water quality loads associated with urban and agricultural landuses and practices. These include the use of sophisticated computer models, typically based on using pollutant loading and runoff functions, regression equations, load export coefficients (LECs), and event mean concentrations (EMCs). This research has examined the feasibility of using a simple EMC approach with the Kentucky Nutrient Model (KYNM). The thesis includes an extensive literature review of EMCs and a synthesis of recommended values for a range of typical urban and agricultural landuses. The thesis also includes an extensive literature review of potential BMPs along with a summary of the typical removal efficiencies and costs associated with each type of BMP. The research also explored the potential to use the results from multiple applications of site specific BMP models like the Source Loading and Management Model (WinSLAMM) in the development of general functional relationships that could then be used to evaluate BMP performance on a more site-specific basis. The developed EMC table and the associated BMP performance curves should provide valuable tools for use in better managing nutrient loads for urban and agricultural watersheds.
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Allen, Roderick Lee. "The applicability of microcomputers to local water management." PDXScholar, 1985. https://pdxscholar.library.pdx.edu/open_access_etds/3417.
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Historically, hydrologic models have been available only on mainframe computers and have therefore not been used by local water managers to support daily decisions. The development of the microcomputer presents an opportunity for that to change.
Mathematical models of soil moisture and river routing are selected, developed and tested for use on a microcomputer as an aid to local water management. The models are then integrated with an appropriate data base in a computer program written for a microcomputer. The result is a Decision Support System for local water managers.
In order to evaluate the feasibility of using the Decision Support System, an application of the program to a small hypothetical river and irrigation system is carried out. The speed of execution indicates that the use of the Decision Support System on this class of computer under the present configuration may be possible if software or hardware changes can reduce data transfer times to and from disk.
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Bertrand, Nathalie Marie-Ange. "Impacts of scaling up water recycling and rainwater harvesting technologies on hydraulic and hydrological flows." Thesis, Cranfield University, 2008. http://dspace.lib.cranfield.ac.uk/handle/1826/4003.
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In recent years, the increasing awareness of scarcity of water resources, indications of likely climate variability, and the increasing pressure to use available fresh water resources more efficiently have together reinforced the need to look at infrastructure solutions with due regard to environmental considerations and social impacts, present and future. There is a vital need to apply an integrated approach to catchment management to implement sustainable solutions to resolve issues such as water supply and sewerage, drainage and river flooding. Many potentials solutions are available to control water demand and manage flood problems. Greywater recycling and rainwater harvesting are novel technologies. However, their catchment scale impacts on hydraulic and hydrological flows are poorly understood. The research aim is to identify the hydrologic and hydraulic impacts of scaling up such technologies at catchment scale. For this particular study, a computer simulation model will be used to evaluate how increasing urbanisation, climate change and the implementation of greywater recycling and rainwater harvesting may alter the water balance within a representative catchment. To achieve these aims data from the Carrickmines catchment in Ireland have been collected; a simulation model has been adapted to carry out the study, the model has been calibrated and validated, results have been analysed, and finally, a sensitivity analysis has been carried out. The results show that rainwater harvesting systems are comparatively more effective than greywater recycling techniques in reducing flood frequency and intensity. Under five year return period rainfall events, the implementation of rainwater harvesting at any scale and number of units is a useful technique to control river flow and floods. However, the study also shows that under extreme conditions the efficiency of rainwater harvesting systems decreases. The study concludes that implementing the two technologies within a single catchment is not a solution to several forms of hydrological problem. The study shows that implementing rainwater harvesting or re-use technologies are a very useful way to protect local freshwater reserves and therefore conserve our environment.
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Busquets, Enrique, and Monika Ivantysynova. "Toward Supervisory-Level Control for the Energy Consumption and Performance Optimization of Displacement-Controlled Hydraulic Hybrid Machines." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-200450.
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Environmental awareness, production costs and operating expenses have provided a large incentive for the investigation of novel and more efficient fluid power technologies for decades. In the earth-moving sector, hydraulic hybrids have emerged as a highly efficient and affordable choice for the next generation hydraulic systems. Displacementcontrolled (DC) actuation has demonstrated that, when coupled with hydraulic hybrids, the engine power can be downsized by up to 50% leading to substantial savings. This concept has been realized by the authors‘ group on an excavator prototype where a secondary-controlled hydraulic hybrid drive was implemented on the swing. Actuatorlevel controls have been formulated by the authors‘ group but the challenge remains to effectively manage the system on the supervisory-level. In this paper, a power management controller is proposed to minimize fuel consumption while taking into account performance. The algorithm, a feedforward and cost-function combination considers operator commands, the DC actuators‘ power consumption and the power available from the engine and hydraulic hybrid as metrics. The developed strategy brings the technology closer to the predicted savings while achieving superior operability.
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Kumar, Vivek. "Hydro-Physical Characterization of Media Used in Agricultural Systems to Develop the Best Management Practices for operation of an Environmentally Sustainable Agricultural Enterprise." FIU Digital Commons, 2012. http://digitalcommons.fiu.edu/etd/787.
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Florida is the second leading horticulture state in the United States with a total annual industry sale of over $12 Billion. Due to its competitive nature, agricultural plant production represents an extremely intensive practice with large amounts of water and fertilizer usage. Agrochemical and water management are vital for efficient functioning of any agricultural enterprise, and the subsequent nutrient loading from such agricultural practices has been a concern for environmentalists. A thorough understanding of the agrochemical and the soil amendments used in these agricultural systems is of special interest as contamination of soils can cause surface and groundwater pollution leading to ecosystem toxicity. The presence of fragile ecosystems such as the Everglades, Biscayne Bay and Big Cypress near enterprises that use such agricultural systems makes the whole issue even more imminent.
Although significant research has been conducted with soils and soil mix, there is no acceptable method for determining the hydraulic properties of mixtures that have been subjected to organic and inorganic soil amendments. Hydro-physical characterization of such mixtures can facilitate the understanding of water retention and permeation characteristics of the commonly used mix which can further allow modeling of soil water interactions.
The objective of this study was to characterize some of the locally and commercially available plant growth mixtures for their hydro-physical properties and develop mathematical models to correlate these acquired basic properties to the hydraulic conductivity of the mixture. The objective was also to model the response patterns of soil amendments present in those mixtures to different water and fertilizer use scenarios using the characterized hydro-physical properties with the help of Everglades-Agro-Hydrology Model.
The presence of organic amendments helps the mixtures retain more water while the inorganic amendments tend to adsorb more nutrients due to their high surface area. The results of these types of characterization can provide a scientific basis for understanding the non-point source water pollution from horticulture production systems and assist in the development of the best management practices for the operation of environmentally sustainable agricultural enterprise
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Ouedraogo, Faissal Romaric. "Impact of Sludge Layer Geometry on the Hydraulic Performance of a Waste Stabilization Pond." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6344.
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Improving the hydraulic performance of waste stabilization ponds (WSPs) is an important management strategy to not only ensure protection of public health and the environment, but also to maximize the potential reuse of valuable resources found in the treated effluent. To reuse effluent from WSPs, a better understanding of the factors that impact the hydraulic performance of the system is needed. One major factor determining the hydraulic performance of a WSP is sludge accumulation, which alters the volume of the pond.
In this study, computational fluid dynamics (CFD) analysis was applied to investigate the impact of sludge layer geometry on hydraulic performance of a facultative pond, typically used in many small communities throughout the developing world. Four waste stabilization pond cases with different sludge volumes and distributions were investigated.
Results indicate that sludge distribution and volume have a significant impact on wastewater treatment efficiency and capacity. Although treatment capacity is reduced with accumulation of sludge, the latter may induce a baffling effect which causes the flow to behave closer to that of plug flow reactor and thus increase treatment efficiency. In addition to sludge accumulation and distribution, the impact of water surface level is also investigated through two additional cases. Findings show that an increase in water level while keeping a constant flow rate can result in a significant decrease in the hydraulic performance by reducing the sludge baffling effect, suggesting a careful monitoring of sludge accumulation and water surface level in WSP systems.
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Lafinhan, Dipo. "The changing governance of UK flood management policies 1998-2010 : a comparative analysis of local approaches in Scotland and England." Thesis, University of Nottingham, 2016. http://eprints.nottingham.ac.uk/33815/.
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The governments of Scotland and England have responded to the increase in flood risk by introducing legislation intended to manage present day flood risk and to avoid future flood risk. This thesis evaluates how the new policy regime has evolved and been implemented in Scotland and England, focusing particularly in Local Authorities, and using contrasts in rural and urban settings to reveal how the policy has had to be adapted to apply effectively in these different physical and administrative environments. Based on discourse theory and the institutionalisation features of policy networks, it is argued first that the new policy regime is subject to multiple interpretations and, second that policy change occurs as a result of the transformation of institutional practices of the multiple flood governance discourses by policy narratives in the policy process. The concept of the advocacy coalition framework is applied to reveal how contrasting local governance approaches result from continuous interactions between national policies and distinctive, local factors. These arguments are supported by the results of empirical research that examined policy change and local governance interpretation through textual analysis of relevant policy documents, interviews with key institutional stakeholders and participant observation of a local stakeholder meeting. Research findings reveal how the more pro-active local governance approaches serve as innovators in informing future national policies. This process stems from local interpretation of existing national policy through the mediating effects of distinctive local policy factors that result in the introduction of new policy ideas and actors. These ideas and the involvement of new actors are in turn transferred through revisions to national policies of flood risk governance. Consequently the policy mediating features of Local Authorities are manifest through first, the utility of policy narratives in driving national policy change and second, in shaping policies in local governance approaches.
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Shrestha, Aashish. "Modeling Impact of Hydraulic Fracturing and Climate Change on Stream Low Flows: A Case Study of Muskingum Watershed in Eastern Ohio." Youngstown State University / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=ysu1420797464.
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Unruh, Hanz. "Research and Education on Water-Energy Nexus| Impact of Hydraulic Fracturing and Thermal Power Generation on Water Resources." Thesis, University of Louisiana at Lafayette, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10642270.
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Unconventional oil and gas extraction has been deployed significantly in the United States in recent years. The current study focuses on the impact of hydraulic fracturing (also known as fracking) on the sustainability of water resources in Louisiana. This impact is measured by quantifying the stress for current and future scenarios of fracking water use in the two main shale plays in Louisiana. The assessment is conducted at the HUC-12 fine catchment spatial scale. Initially, sectored stress metrics were calculated for surface and groundwater, respectively, without including fracking water use. Once both stress metrics were estimated with the reported water sources and uses in Louisiana corresponding to the 2010 year, several scenarios for both sources were evaluated. In the first scenario, a peak year (2011) of fracking water use was added as a water demand new category into the stress calculation matrices. The results indicate that a significant variability in the calculated stress metric with and without fracking is reflected only for the groundwater sector. The second Existing wells scenario calculates the stress including the water use of the total number of wells that currently exist in both shale plays over a brief time period. The other additional tested scenario consists of an increase of 100% of the required number of wells to extract the expected total shale play capacity. Results of the additional scenarios follow the same pattern as the first scenario. This analysis can be useful for water management authorities to consider several factors, such as cost analysis of recycled flow-back, as alternative resources for fracking water use. In addition to this fracking water use impact on resources analysis, an educational web-module comprising the Energy-Water Nexus is developed in the current study. The core of the educational module available online is contained in the learning activities development.
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Lammers, Zachary A. "Thermal Management of Electromechanical Actuation System for Aircraft Primary Flight Control Surfaces." University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1399021324.
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Chu, Hsuan-Wen. "A Stormwater Management Model for California Polytechnic State University Campus." DigitalCommons@CalPoly, 2018. https://digitalcommons.calpoly.edu/theses/1977.
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Developments that have been taking place on Cal Poly campus over the years have altered the natural hydrology of the area. Stormwater management practices could help reduce the impacts of these developments. Computer models can help to design effective and economical stormwater management solutions at a watershed scale. As such, the objective of this study was to develop a stormwater management model for Cal Poly campus. The model was developed based on the utility data obtained from the university and other watershed data available from open sources. Field surveys were conducted to address some anomalies in the utility data, and streamflow monitoring was performed. The model was calibrated using the streamflow data measured during this study. The calibration effort significantly improved the prediction accuracy of the model. The calibrated model was then used to analyze the hydrologic performance of implementing LID systems for two projects that Cal Poly plans to build. Permeable Pavements (PPs) and Bioretention Cells (BRCs) were the LID types examined. The LIDs were evaluated based on peak flow and runoff volume reductions they would achieve. The potential reductions were compared for current conditions and the proposed project if LIDs were implemented, and for inflows to the LIDs and outflows from the LIDs. The results indicate that implementing a PP system for the proposed student apartment at the current H-1 and R-1 parking lots and a BRC system for the proposed engineering project facilities at the current H-2 parking lots will significantly reduce peak flow and runoff volume. Overall, the developed model will help the university with the traditional stormwater management practices such as flood control and to identify effective LID practices for future developments. Limitations of the current model and recommendations on how to improve the model are also discussed.