Tesis: "Shortage of fresh water"

1

Zhao, Yu. "Reverse osmosis desalination in a mini renewable energy power supply system". Thesis, Curtin University, 2006. http://hdl.handle.net/20.500.11937/2099.

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The design, construction and testing of a reverse-osmosis (PV-RO) desalination system for fresh water shortage area is presented. The system operates from salt water or brackish water and can be embedded in a renewable energy power supply system, since many fresh shortage areas are remote and isolated. Special attention is given to the energy efficiency of small-scale reverse osmosis desalination systems. Limitations of conventional control strategy using toggle control are presented. Based on this, an objective of creating a small-scale reverse osmosis desalination system was set out. Initially, the background information is presented. This includes the natural resources crisis and main desalination technologies and the viability of the integration with renewable energy source. A reverse osmosis (RO) desalination system was assembled and set up at the Curtin University of Technology, Perth, Western Australia Supervisor Control And Data Acquisition (SCADA) system was built using a Human Machine Interface software and a programmable logic controller (PLC). Instrumentation that included signal conditioners was made in analysis of the system characteristics. Initial testing of the system was conducted after the system design and configuration was accomplished. Testing results were used as a guideline for the development of the whole system.Modelling and simulation of the system components in MATLABSimulink is presented, together with a discussion of the control systems modelling and design procedure, in which the aim was to improve the efficiency of the reverse osmosis system. Simulations show the designed reverse osmosis system with Proportional Integral and Derivative (PID) controller has better performance than other controllers. This consequently leads to a lower overall cost of the water, as well as reducing full maintenance cost of the electric drives in the reverse osmosis unit. Additionally, the configuration of the remote control system through General Package Radio System (GPRS) network is depicted. After the PID control algorithm was programmed into the Programmable Logic Controller (PLC), system experiments were carried out in short durations and long durations. System performance was monitored and experimental results prove that the new control strategy applied increase the water productivity and is able to improve the system efficiency up to 35%. Based on the data obtained from the simulations and experiments, Mundoo Island was chosen to be the location for a case study. The electric load profile of the island was derived from the Island Development Committee in Mundoo.A water demand profile was created and modelled in Matlab to be the input of the reverse osmosis system. The electric load of the reverse osmosis system was generated from Matlab simulation. This result was entered in Hybrid Optimisation Model for Electric Renewables (HOMER) simulator. Having the designed RO unit as one of the electric loads, the entire remote area power supply (RAPS) system was tested in simulations which shows the energy cost is AUS$0.174 per kWh, lower than the Island Development Committee budget estimation of AUS$0.25 per kWh. The cost of the water treatment is very promising at AUS$0.77 per m3.

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2

Hafstad, Elin. "Naturliga vattenreservoarer i vattenbristområden i Stockholms skärgård : En studie på öarna Ornö, Svartsö och Vindö". Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298264.

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Vattenförsörjningsproblemen är stora i Stockholms läns kustområden. Enskilda brunnar försörjer invånarna med grundvatten, dock är förutsättningarna dåliga för större uttag. I takt med ett ökat permanentboende i den peri-urbana skärgården ökar även behovet av vatten, som är människans absolut viktigaste resurs. Ett ökat uttag hotar med högre risk för saltvatteninträngning och sinade brunnar. Vattenbrist lär kunna bli allt vanligare även i takt med klimatförändringarna. För att säkra en framtida hållbar utveckling för skärgården måste därför alternativa lösningar på vattenförsörjningsfrågan hittas. Många av de större öarna i skärgården har naturliga vattenreservoarer också ovan mark i form av sötvattensjöar. Arbetets huvudsyfte har därför varit att undersöka möjligheten till att kunna nyttja dessa vattenlager som en del i öarnas vattenförsörjning. Fokus för arbetet har legat på att kartlägga vattenbehovet idag och i framtiden, vilka vattentillgångar som finns samt hur dessa kan användas och implementeras utifrån dagens vattenproduktion på tre valda öar, Ornö, Svartsö och Vindö. Genom intervjuer och kontakter med öbor samt litteratur- och fältstudier har resultaten kunnat visa att vattenförsörjningen från sjöarna idag som mest endast ligger på cirka 10 procent av den totala förbrukningen. Vidare bedöms möjligheten vara god till att kunna utöka användningen av sjöar på öarna i vattenförsörjningssyfte. Särskilt gäller detta oligotrofa sjöar i närheten av bebyggelse. Samtidigt kan det finnas många olika intressen för en sjö i skärgården och vattenförsörjningen är en stor kostnadsfråga. Upprättande av gemensamma, kombinerade vattenlösningar anses vara gynnsamt, med ett renat sjövatten sommartid som kan avlasta grundvattenreservoarerna.
The water supply problems are large in Stockholm County's coastal areas. Individual wells supply the inhabitants with groundwater, however, the conditions are poor for larger outlets. In step with an increase in permanent housing in the peri-urban archipelago, the need for water, which is man's most important resource, is also increasing. An increased outlet threatens with a higher risk of saltwater penetration and drained wells. Water shortage is likely to become more common even in step with climate change. In order to secure a future sustainable development for the archipelago, alternative solutions to the water supply issue must therefore be found. Many of the larger islands in the archipelago also have natural water reservoirs above ground in the form of freshwater lakes. The main purpose of this study has therefore been to investigate the possibility of being able to use these water reservoirs as part of the islands' water supply. The focus of the study has been on mapping the water demand today and in the future, what water resources are available and how these can be used and implemented based on current water production on three selected islands, Ornö, Svartsö and Vindö. Through interviews and contacts with islanders as well as literature and field studies, the results have been able to show that the water supply from the lakes today constitutes at most only about 10 percent of the total consumption. Furthermore, the opportunity to be able to increase the use of lakes on the islands for water supply purposes is considered to be good. This mainly applies to oligotrophic lakes in the vicinity of built-up areas. However, there can be many different interests for a lake in the archipelago and the water supply is a major cost issue. Establishment of joint, combined water solutions is considered beneficial, with purified water from lakes in the summertime that can relieve the groundwater reservoirs.

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3

Zhao, Yu. "Reverse osmosis desalination in a mini renewable energy power supply system". Curtin University of Technology, Dept. of Electrical and Computer Engineering, 2006. http://espace.library.curtin.edu.au:80/R/?func=dbin-jump-full&object_id=18552.

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The design, construction and testing of a reverse-osmosis (PV-RO) desalination system for fresh water shortage area is presented. The system operates from salt water or brackish water and can be embedded in a renewable energy power supply system, since many fresh shortage areas are remote and isolated. Special attention is given to the energy efficiency of small-scale reverse osmosis desalination systems. Limitations of conventional control strategy using toggle control are presented. Based on this, an objective of creating a small-scale reverse osmosis desalination system was set out. Initially, the background information is presented. This includes the natural resources crisis and main desalination technologies and the viability of the integration with renewable energy source. A reverse osmosis (RO) desalination system was assembled and set up at the Curtin University of Technology, Perth, Western Australia Supervisor Control And Data Acquisition (SCADA) system was built using a Human Machine Interface software and a programmable logic controller (PLC). Instrumentation that included signal conditioners was made in analysis of the system characteristics. Initial testing of the system was conducted after the system design and configuration was accomplished. Testing results were used as a guideline for the development of the whole system.
Modelling and simulation of the system components in MATLABSimulink is presented, together with a discussion of the control systems modelling and design procedure, in which the aim was to improve the efficiency of the reverse osmosis system. Simulations show the designed reverse osmosis system with Proportional Integral and Derivative (PID) controller has better performance than other controllers. This consequently leads to a lower overall cost of the water, as well as reducing full maintenance cost of the electric drives in the reverse osmosis unit. Additionally, the configuration of the remote control system through General Package Radio System (GPRS) network is depicted. After the PID control algorithm was programmed into the Programmable Logic Controller (PLC), system experiments were carried out in short durations and long durations. System performance was monitored and experimental results prove that the new control strategy applied increase the water productivity and is able to improve the system efficiency up to 35%. Based on the data obtained from the simulations and experiments, Mundoo Island was chosen to be the location for a case study. The electric load profile of the island was derived from the Island Development Committee in Mundoo.
A water demand profile was created and modelled in Matlab to be the input of the reverse osmosis system. The electric load of the reverse osmosis system was generated from Matlab simulation. This result was entered in Hybrid Optimisation Model for Electric Renewables (HOMER) simulator. Having the designed RO unit as one of the electric loads, the entire remote area power supply (RAPS) system was tested in simulations which shows the energy cost is AUS$0.174 per kWh, lower than the Island Development Committee budget estimation of AUS$0.25 per kWh. The cost of the water treatment is very promising at AUS$0.77 per m3.

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4

Wallenburg, Mary K. "The nursing shortage: a fresh perspective". [Denver, Colo.] : Regis University, 2008. http://165.236.235.140/lib/MWallenburg2008.pdf.

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5

Saleh, Mohamed Al-Azhari M. "Modelling irrigation water management under water shortage and salinity conditions". Thesis, University of Edinburgh, 2006. http://hdl.handle.net/1842/11348.

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The usefulness of mathematical models in identifying efficient management strategies under uncertain conditions is, however limited by the theories used in models as well as by the availability and quality of field data that can be used in the calibration and validation of these models. Many models have been developed and used to simulate water and solute flux in the crop rootzone. This thesis describes the development and application of two different models, the WAVE and UNSATCHEM models to simulate water and solute transport in the vadose zone and their effect on crop transpiration and yield. The WAVE model was modified to include the effect of salinity on crop transpiration, and used to simulate soil water balances, to investigate long-term salinity build-up in the root zone, and in conjunction with a crop yield response model to assess their effect on crop yield. The practicality of the modelling approach in the establishment of optimal irrigation and drainage practices is considered through application to the Makhtaaral region of South Kazakhstan. The impact of several irrigation and drainage scenarios was evaluated. Optimal irrigation and drainage strategies for sustainable crop production have been derived. The application of the UNSATCHEM model as a multi-species model to the Makhtaaral region is also demonstrated for the evaluation of the current irrigation and drainage practices. For the problem considered in this study, the WAVE model along with the crop yield response model can be used as a tool for assessing the impact of different irrigation and drainage scenarios on crop yield. The results demonstrate that the modelling approach is robust and applicable under arid and semi-arid conditions and to a wide range of water shortage and salinity.

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6

Alsaeedi, Abdullah Hassan. "Utilizing ground water contributions to resolve irrigation water shortage in Al-Hassa". Thesis, Open University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262511.

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7

Maher, Duarte. "IoT for fresh water quality monitoring". Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-235179.

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Water is one of the most important resources in the world. It has direct impact on the daily life ofmankind and sustainable development of society. Water quality affects biological life and has to obeystrict regulations. Traditional water quality assurance methods, used today, involve manual samplingfollowed by laboratory analysis. This process is expensive due to high labour costs for sampling andlaboratory work. Moreover, it lacks real time analysis which is essential to minimise contamination.This thesis aims to find a solution to this problem using IoT sensors and Machine Learning techniquesto detect anomalies in the water quality. The spatial scalability is key requirement when selecting transmissionprotocols, as sensors could be spread around the water network. We consider solutions readilyavailable or soon to be in the market. The key LPWAN technologies studied are: SigFox, LoRaWANand NB-IoT. In general these protocols have many characteristics essential for fresh water monitoring,like long lasting battery life and long range, however, they have many limitations in terms of transmissiondata rates and duty cycles. It is therefore essential to find a solution that would correctly find anomaliesin the water quality but at the same time comply with limited transmission and processing capabilities ofthe node sensors and above mentioned protocols.A trial sensor is already in place in lake M¨alaren and its readings are used for this study. Supervisedmachine learning algorithms such as Logistic Regression, Artificial Neural Network, Decision Tree, OneClass K-NN and Support Vector Machine (SVM) are studied and discussed regarding the data available.SVM is then selected, implemented and optimised to comply with the limitations of IoT. The trade offbetween false anomalies and false normal readings was also discussed.
Vatten ä r en av de viktigaste resurserna i vä rlden. Det har direkt inverkan på mä nsklighetens dagliga liv och samhä llets hå llbara utveckling. Vattenkvaliteten på verkar det biologiska livet och må ste fö lja strikta fö reskrifter. Traditionella metoder fö r vattenkvalitetssä kring, som anvä nds idag, innefattar manuell provtagning fö ljt av laboratorieanalys. Denna process ä r dyr på grund av hö ga arbetskostnader fö r provtagning och laboratoriearbete. Dessutom saknar den realtidsanalys som ä r vä sentlig fö r att minimera‌fö rorening.Avhandlingen syftar till att hitta en lö sning på detta problem med hjä lp av IoT-sensorer och maskinlä rningsteknik fö r att upptä cka avvikelser i vattenkvaliteten. Den spatiala skalbarheten ä r ett viktigt krav vid val av ö verfö ringsprotokoll, eftersom sensorer kan spridas runt vattennä tverket. Vi diskuterar lö sningar som ä r lä ttillgä ngliga eller snart ska vara på marknaden. De viktigaste LPWAN-teknikerna som studerats ä r: SigFox, LoRaWAN och NB-IoT. Generellt har dessa protokoll må nga egenskaper som ä r nö dvä ndiga fö r ö vervakning av fä rskvatten, som lå ng batterilivslä ngd och lå ng rä ckvidd, men de har må nga begrä nsningar vad gä ller ö verfö ringshastighet och arbetscykel. Det ä r dä rfö r viktigt att hitta en lö sning som skulle hitta anomalier vid hö gt sä kerhet men samtidigt ö verensstä mmer med begrä nsade ö verfö ringsoch bearbetningskapaciteter hos sensorerna och de ovan nä mnda protokoll.En fö rsö kssensor finns redan på plats i Lake Mä laren och dess avlä sningar anvä nds fö r dennastudie.Ö vervakade maskininlä rningsalgoritmer, så som Logistic Regression, Artificial Neural Network,Decision Tree, One Class K-NN and Support Vector Machine (SVM) studeras och diskuteras beträ ffande tillgä ngliga data. SVM vä ljs sedan, implementeras och optimeras fö r att uppfylla IoTs begrä nsningarna.Balansen mellan falska avvikelser och falska normala avlä sningar diskuteras också .

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8

Pearce, Ariel Leah. "Fresh Water Scenes in Minoan Art". Diss., Temple University Libraries, 2017. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/451958.

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Art History
Ph.D.
The goal of this dissertation is to provide a comprehensive study of scenes of fresh water in Minoan art from the Middle Minoan II (MM II) through the Late Minoan I (LM I) periods. This dissertation addresses and fills the gap in the scholarship regarding the depiction of riparian environments and the special place of these depictions in Aegean art. It also attempts to clarify the use and function of riverscapes across chronological periods. Rivers, marshes, streams, and springs, appear on a variety of media and fulfil multiple functions from MM II onward. Images of fresh water were used as topographical markers, ornamentation and decoration, and for religious purposes. Moreover, several images suggest that the Minoans may have believed that the realm for the goddess (or one of the goddesses) was a lush, riverscape. A second goal of this dissertation is to clarify and dispose of the term “Nilotic” as a label for images of fresh water in the Aegean. Since its introduction into the literature of Aegean studies in the beginning of the 20th century, the term “Nilotic” has been used inconsistently to describe Aegean scenes of fresh water that may or may not contain Egyptian elements. This assumption has led some scholars to state that Aegean riverscapes are ultimately derived from Egyptian scenes of fishing and fowling because they share similar iconographic elements. Unfortunately, the process of synthesis is important to the understanding of Aegean riverscapes, and iconographic similarities are somewhat superficial. Furthermore, the term has been used without regard for a long-standing tradition of the depiction of riparian environments in Bronze Age Aegean art. To fully address both goals of this project, the origin of individual iconographic elements has been traced through various media, including glyptic art, pottery, and wall painting. Wall paintings from the Cyclades and some Late Helladic IA scenes have been included when appropriate. Whenever possible, categories of riverscapes have been grouped together, but each wall painting, has been examined and interpreted individually. Some unique, highly pictorial, and detailed images in other media have also been addressed separately. Parallels in Egyptian and, in some cases, Near Eastern art have been sought to determine the validity of the term “Nilotic,” and a special study of Egyptian scenes of hunting in the marshes has been conducted in comparison to Aegean scenes. Iconography, synthesis, and context have all been taken into consideration.
Temple University--Theses

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9

Schulze, Lucy y Lena Bauer. "Water, Water, Everywhere? : How Different Stakeholders Perceive and Address the Water Shortage on Gotland, Sweden". Thesis, Uppsala universitet, Företagsekonomiska institutionen, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-325049.

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“Vattenfrågan har alltid varit viktig på Gotland” (Bastani et al. 2015, p. 25) - “Water questions have always been important on Gotland”. Contrary to the common perception that water shortage does not pose a problem to northern European countries, the case on Gotland provides the example that it is a real issue. Due to several factors, the Swedish island faces severe water shortages during the summer and is in urgent need to address this in the light of an expected growing number of people coming to Gotland. Since water is a topic affecting a wide range of stakeholders, the water issue is already in the focus of attention and occasionally passionately discussed on the island. The aim of this paper was to identify with the help of qualitative research how relevant stakeholder groups perceive and address the water shortage on Gotland. The identified stakeholder groups were from the administrative/political sectors, industrial/business sectors, the research sector as well as engaged citizens. During the research it became clear that the water shortage can be characterized as a wicked problem, which in its nature is impossible to solve but only manageable due to its complexity. Yet, the majority of stakeholders did not recognize the wicked problem as such which explains the multiplicity of existent strategies for how to deal with it. The different approaches lead to outcomes that seem to only address parts of the problem but fail to manage it in its entirety. The study suggests that institutional voids, meaning a lack of clear responsibilities regarding who should manage the problem and how seem to both arise from and contribute to the complexity of the problem. As result of this research, it seems crucial to firstly gain a comprehensive understanding of the situation and then work with multi stakeholder communication and cooperation against prevailing institutional voids in order to address the water shortage effectively.

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10

Mulholland, Holly. "Water politics in the Middle East a multicase approach to regional water shortage". Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4988.

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Water shortage is a salient issue in the Middle East commonly overshadowed by more sensational topics such as the oil crisis and the Arab-Israeli Conflict. There is a debate among scholars as to whether water shortages in the Middle East will destabilize the region into armed conflict. Realists argue that non sustainable water sources will be the catalyst which will inevitably lead states to fight one another in a zero-sum game over limited water resources. Liberal Functionalists argue that there are precedents for multilateral cooperation and a technical approach may hold the key to providing solutions to the current water crisis. This research will examine three case studies from the Middle East region: the Jordan River Basin, the Tigris and Euphrates River Basin, and the Disi Aquifer on the border of Jordan and Saudi Arabia. Limited to a specific geographic region, these cases are indicative of water shortages that have or will become potential geostrategic centers for the water crisis.
ID: 029810515; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.A.)--University of Central Florida, 2011.; Includes bibliographical references.
M.A.
Masters
Political Science
Sciences

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11

Aura, Stella M. (Stella Marris). "Fresh water forcing of the North Atlantic". Thesis, McGill University, 1992. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=56641.

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Several numerical experiments are carried out using the Bryan-Cox Ocean General Circulation Model to investigate the variability of the North Atlantic thermohaline circulation under steady, non-zonal, surface forcing and realistic geometry. To this end the annual mean surface forcing fields were derived from the climatological data sets of Levitus (1982), Hellerman and Rosenstein (1983) and, Schmitt et al. (1989). Further, Arctic freshwater flux, an important part of the hydrological cycle within the North Atlantic Deep Water formation region, is taken into account.
It is found that under present-day climatological surface forcing the system may oscillate at interdecadal period. The mechanism driving the oscillations is linked to changes in both the horizontal and vertical extent of convection in the northern "Labrador Sea". The structure of the surface freshwater flux forcing plays a major role in both the initiation and sustenance of the interdecadal oscillations. Allowing for a freshwater flux into the northern region of the "Labrador Sea" inhibits the interdecadal variability. The oscillations, however, appear, relatively insensitive to Arctic fresh water transport into the "Greenland Sea".
A detailed three-dimensional discussion of the physics behind the interdecadal oscillations is presented.

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12

PICINARDI, Alberto. "Cogeneration of cooling energy and fresh water". Doctoral thesis, Università degli studi di Bergamo, 2011. http://hdl.handle.net/10446/883.

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A design simulation of the cogeneration system allowed to chose the best HD unit configuration, while a TRNSYS off-design simulation revealed the main design variables on which to focus the optimization. The optimization study on the design variables was performed by GenOpt, a generic optimization program which minimizes an objective function with respect to multiple variables. This study has been carried out on different objective functions and reveals that maximizing the production of cooling energy means damaging the fresh water production. A compromise solution has been chosen to balance the contrast between cooling energy and fresh water production.

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13

PICINARDI, Alberto. "Cogeneration of cooling energy and fresh water". Doctoral thesis, Università degli studi di Bergamo, 2011. http://hdl.handle.net/10446/222125.

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A design simulation of the cogeneration system allowed to chose the best HD unit configuration, while a TRNSYS off-design simulation revealed the main design variables on which to focus the optimization. The optimization study on the design variables was performed by GenOpt, a generic optimization program which minimizes an objective function with respect to multiple variables. This study has been carried out on different objective functions and reveals that maximizing the production of cooling energy means damaging the fresh water production. A compromise solution has been chosen to balance the contrast between cooling energy and fresh water production.

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14

Crombie, Stephanie. "Carbon and water vapour exchange in a temperate fresh water marsh". Thesis, McGill University, 2013. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=114374.

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The ability of wetlands to sequester carbon has given them a considerable amount of attention, especially in light of global climate change. To date, many wetland studies have focused on peatlands, however very few studies have been conducted on marshes. This study used the eddy covariance (EC) technique to measure net ecosystem carbon exchange (NEE) and energy exchange at a temperate freshwater cattail marsh near Ottawa, Canada. The objectives of the study were to use a four year dataset to determine the environmental controls on the variability of carbon and water vapour exchange. The annual cumulative NEE was on average -246 ± 31 gCm-2yr-1 ranging from -216 to -260 gCm-2yr-1. The variability in accumulation between years was a result of the timing of spring and fall transitions in the carbon uptake and the length of the growing seasons, each of which were determined by prevailing weather conditions. Evaluation of the interannual variability indicated that the marsh may be sensitive to carbon (C) losses through enhanced respiration under warmer autumn periods. Maximum daily average values of evapotranspiration (ET) reached 10.75, 9.07, 11.70 and 8.36 mm day-1 in 2005, 2006, 2007 and 2008, respectively. Bowen ratio values varied seasonally with values well below unity during the growing season (May to October) illustrating the dominance of latent heat. Evaluation of the evaporative fraction and Priestley-Taylor α indicated the seasonal importance of ET and mid-season high values of the decoupling coefficient (Ω) indicated that the marsh ET is radiatively driven owing its smooth aerodynamic surface and abundance of water. Overall, the marsh ecosystem was a large annual sink for CO2 as compared to other wetland ecosystems and ET rates were highly dependent on radiative input.
La capacité des milieux humides à séquestrer du carbone a beaucoup attiré l'attention, notamment dans le contexte des changements climatiques. À ce jour, bien que plusieurs études aient été menées sur les tourbières, très peu portent sur les marais. Cette étude a utilisé la technique de covariance des turbulences afin de mesurer l'échange écosystémique net (EEN) de CO2 et l'échange d'énergie d'un marécage de quenouilles de l'est de l'Ontario, Canada. Les objectifs de cette étude étaient d'utiliser un ensemble de données de quatre ans afin de déterminer les contrôles environnementaux sur la variabilité des échanges de carbone et de vapeur d'eau. Le EEN annuel cumulé était en moyenne de -246 ± 26,8 gCm-2a-1 allant de -216 à -260 gCm-2a-1. La variabilité de l'accumulation entre les années était le résultat de la synchronisation du printemps et de l'automne au niveau de l'absorption du carbone et de la longueur des saisons de croissance, chacune ayant été déterminée par les conditions météorologiques qui prévalaient. L'étude de la variabilité interannuelle a indiqué que le marécage pourrait être sensible aux pertes de C causées par une augmentation de la respiration au cours de périodes plus chaudes d'automne. Les valeurs moyennes quotidiennes maximales d'évapotranspiration (ET) ont atteint 10,75, 9,07, 11,70 et 8,36 mm jour-1 en 2005, 2006, 2007 et 2008 respectivement. Les valeurs du rapport de Bowen variaient selon la saison, avec des valeurs bien en dessous de l'unité pendant la saison de croissance (mai à octobre), illustrant la dominance de la chaleur latente. Une évaluation de la fraction d'évaporation et du facteur α de Priestley-Taylor indiquaient l'importance saisonnière de l'ET et les valeurs élevées de mi-saison du facteur de découplage (Ω) indiquaient que l'ET du marais est dominé par les radiations en raison de sa surface aérodynamique lisse et de l'abondance d'eau. Dans l'ensemble, l'écosystème du marais était un grand puits de carbone annuel par rapport aux écosystèmes de tourbière et les taux d'ET étaient fortement dépendants de l'apport radiatif.

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15

Brettell, Jonathan James. "Walking Severn miles : the affordances of fresh water". Thesis, Aberystwyth University, 2016. http://hdl.handle.net/2160/a3f9f979-c722-48c7-9dbf-45551ca10864.

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Following a call from Linton (2010) to think more relationally about water this thesis seeks to explore the infolding and unfolding relations that take-form between bodies around particular characteristics of freshwater. There is a tradition of exploration regarding the sustainability, quality, monitoring and management of water when we encounter research on human associations with fluvial hydrology, and whilst this work is important, this project looks to enrol more nascent and contemporary geographical themes to broaden our understanding of encounters with freshwater landscapes, and take a more relational approach to fluvial geographies. These works then shall address a gap in the geographical literature and describe the personal, pre-personal and affective worlds that emerge when bodies become down by the river. Whilst this is not specifically a walking project, walking the course of the River Severn serves as a trajectory along which processual ideas of bodies on the move shall be mobilised. A series of creatively written segues will link together a sequence of theoretical and conceptually driven site ontologies (Marston et al 2005; Woodward et al 2010) and relations associated with the Severn and freshwater more broadly. The flow and form of the thesis will reflect the multivariant characteristics of water and its varying speeds and slownesses. The chapters will step into puddles, mooch about in a ships graveyard, rethink the source of a river, paddle a coracle and set the scene for how an ontological, relational approach to fluvial landscapes can contribute to geographical thinking. The works will focus on human-nonhuman relations, vibrant materialities and elemental mobilities, in so doing enable further understanding of how we can apprehend sites as moments of coherence in a turbulent world, and contribute to broadening our scope of knowledge of the more-than-human.

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16

Tereshchenko, I. M. "The effects of acidification on fresh water life". Thesis, Сумський державний університет, 2014. http://essuir.sumdu.edu.ua/handle/123456789/34942.

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Signs that a water body is becoming acidified are clearer water and declining fish populations. The clearness is primarily due to that the humic substances that normally colour the water, precipitate and settle on the lake floor. The main reason for fish stocks declining, both overall and in number of species, is failure to reproduce in acidic water. Many other biological changes occur, too, when the water becomes acidified. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/34942

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17

Västberg, Erika. "Hållbar vattenförsörjning i områden med vattenbrist : Sustainable water supply solutions for areas affected by water shortage". Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-224957.

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In some coastal areas in Sweden water shortage sometimes appears because the withdrawal of groundwater is greater than the groundwater recharge. It creates a situation where the available groundwater is insufficient to support residents and businesses with drinking water. The high withdrawal of groundwater also creates a risk for saltwater intrusion to drinking water wells. The problem most commonly occurs during the summer when the groundwater recharge is low, but the population is high, due to tourism and summer residents. The purpose of this study was to investigate how local water supply in areas affected by water shortage can be solved as sustainable as possible. The work was divided into three parts where the first part comprised of a literature review on water systems in which four different options were investigated: artificial groundwater recharge, rainwater harvesting, desalination and water reuse. The second part of the work consisted of developing a method for choosing the best water supply solution based on nature-given and social conditions. The method evaluated the quality of the supplied water and disease control, technical robustness, environmental impacts and resource use, liability and user aspects, the possibility for rebuilding and costs. Multi-criteria analysis (MCA) was used as a decision tool. The last part of the thesis was to test the method on a case study area, Grisslehamn in Norrtälje. Four systems alternatives were compared: desalination of sea water, building a surface water treatment plant supplied by water from two nearby fresh water ponds, rainwater harvesting at household level and collection and central treatment of greywater in combination with the construction of a surface water treatment plant. The results from the MCA showed that seawater desalination as a complement to the existing water plant was the best option for Grisslehamn followed by the surface water plant, collection of greywater and finally rainwater harvesting. Costs and possibility for rebuilding was shown to have a large impact on whether desalination or building of a surface water treatment plant was the best option. Therefore it is important in any future studies that detailed investigations of water quality and costs are done before decision is made on which one of the two alternatives that is the best solution for Grisslehamn.

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Oliveira, MarcÃlio Caetano de. "Proposed methodology of allocation of water in periods water shortage for vale do Rio Curu-CearÃ". Universidade Federal do CearÃ, 2013. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=11199.

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A escolha acertada de um modelo de alocaÃÃo de Ãgua em perÃodos crÃticos ameniza o sofrimento causado pela ausÃncia de um bem tÃo precioso. Apesar da infraestrutura hÃdrica existente, o estado do CearÃ vem sofrendo com os problemas causados pela estiagem. A metodologia de alocaÃÃo de Ãgua, sobretudo em perÃodos de escassez, precisa ser formatada e discutida com os agentes envolvidos nesse processo. Esta pesquisa tem como objetivo apresentar uma proposta de estratÃgia para alocaÃÃo de Ãgua, em perÃodo de escassez, para o Vale do Rio Curu, CearÃ, construÃda a partir da junÃÃo de dois mecanismos de alocaÃÃo: a formaÃÃo de consenso entre usuÃrios e instrumentos econÃmicos. Ã demonstrado, para isso, que o uso da Ãgua no Vale do Curu Ã predominante na atividade de irrigaÃÃo. Dessa forma, a estratÃgia proposta Ã composta por um sistema de prioridades de uso de Ãgua intrassetorial para irrigaÃÃo, com base na cobranÃa pelo uso da Ãgua variando em funÃÃo da garantia de longo prazo. Os recursos arrecadados com essa cobranÃa serÃo utilizados para pagamento de seguro e compensaÃÃo financeira, em anos secos, aos usuÃrios com garantia menores. A metodologia de alocaÃÃo proposta alcanÃou resultados satisfatÃrios quanto aos critÃrios de eficiÃncia econÃmica, legitimidade e sustentabilidade polÃtica, equidade, sustentabilidade financeira e capacidade de adaptaÃÃo. Para sua efetiva implantaÃÃo, foram sugeridas as medidas necessÃrias de controle, monitoramento e fiscalizaÃÃo do uso da Ãgua, alÃm da adequaÃÃo da legislaÃÃo vigente. A discussÃo e deliberaÃÃo pelo ComitÃ de Bacia HidrogrÃfica do Rio Curu foi apresentada como premissa fundamental para efetivaÃÃo da metodologia proposta
The right choice of a model of water allocation in critical periods alleviates the suffering caused by the absence of so precious. Despite the existing water infrastructure, the state of CearÃ has been suffering with the problems caused by drought. The methodology for allocation of water, especially in times of scarcity needs to be formatted and discussed with stakeholders in this process. This research aims to propose a strategy for allocating water in lean period for the River Valley Curu, CearÃ, built from the junction of two allocation mechanisms consensus building between users and economic instruments. It is shown that for this water use in Curu Valley is dominantly in the activity irrigation. Thus the proposed strategy consists of the definition of a system of priorities for the use of intra-sectoral water for irrigation from the payment of charges for water use varies depending on the long-term warranty. The funds raised from this collection will be used to pay insurance and financial compensation, in dry years, users with lower collateral. The proposed allocation methodology achieved satisfactory results regarding the criteria of economic efficiency, legitimacy and political sustainability, equity, financial sustainability and adaptability. For its effective implementation were suggested appropriate measures for monitoring, control and supervision of water use, the adequacy of current legislation. The discussion and deliberation by the committee River basin Curu was presented as a prerequisite for realization of the proposed methodology

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19

Nash, Brett Jason. "Confluence of the law of fresh water resources and international trade : do Canada’s international trade obligations apply to Canada’s fresh water resources?" Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/57777.

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This thesis explores whether international trade rules apply to Canada’s fresh water resources. In order to determine if international trade rules apply, in particular the rules contained in GATT 1947, GATT 1994, and NAFTA, three questions are posed by the author. The first question focuses the enquiry on the legal characterization of fresh water resources in the selected international legal instruments to determine the obligations contained in the trade agreements apply. The second question is, if the first question cannot be answered, what other interpretive tools can be employed to come to an answer. Finally, the third question is, if international trade obligations apply the the bulk export of fresh water resources, are there any exemptions which can be employed to limit or prohibit the bulk export of the resource. In order to answer these questions, the author applies a traditional legal doctrinal analysis. This provides a method of analyzing the legal texts of the international agreements and other legal materials in an orderly and systematic manner. Using this methodology, the author engages with the primary materials to determine the ordinary meaning of the words and phrases used in the texts. In addition to the analysis of the legal texts, the author reviews the history of the development of Canada’s international trade and foreign policy through the lens of the international relations theory of exogenous shock. By using the theory of exogenous shock as an interpretive aid, the author is able to provide justification in concluding that the preferred interpretation that Canada’s international trade obligations found in GATT and NAFTA do not apply to Canada’s fresh water resources.
Law, Peter A. Allard School of
Graduate

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20

Hyer, Eric L. "Fresh Water Ecology Unit for Secondary Education Science Courses". Diss., CLICK HERE for online access, 2007. http://contentdm.lib.byu.edu/ETD/image/etd1762.pdf.

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21

Yoder, Madonna K. "Lower Charles River bathymetry : 108 years of fresh water". Thesis, Massachusetts Institute of Technology, 2017. http://hdl.handle.net/1721.1/114326.

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Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2017.
Cataloged from PDF version of thesis.
Includes bibliographical references (page 22).
The Lower Charles River has been a heavily utilized urban river that runs between Cambridge and Boston in Massachusetts. The recreational usage of the river is dependent on adequate water depths and there have been no definitive prior studies on the sedimentation rate of the Lower Charles River. The river transitioned from tidal to a freshwater basin in 1908 and the study area for historical comparisons was from the old Charles River Dam to the Boston University Bridge. This study surveyed the river, digitized three prior surveys that spanned 114 years, calculated volumes and depth distributions for each survey, and estimated sedimentation rates from fits to the volumes over time. The average sedimentation rate is estimated as 5-10 mm/year, which implies 1.8-3.5 feet sedimentation since 1908. Sedimentation rates and distributions are necessary to develop comprehensive management plans for the river.
by Madonna K. Yoder.
S.B.

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22

George, Alabodite M. "Numerical simulation of warm discharge in cold fresh water". Thesis, Loughborough University, 2017. https://dspace.lboro.ac.uk/2134/27376.

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Buoyant plumes in cold fresh water are of interest because of the possibility of buoyancy reversal due to the nonlinear relation between temperature and density in water. Thus an initially rising plume may become a fountain. This project aims to mathematically model such plumes and fountains using numerical simulation by the means of a commercial software, Comsol Multiphysics. Both turbulent and lam- inar cases were investigated in different geometries, and with the assumption that density is a quadratic function of temperature. The turbulent flow cases as con- sidered here in this thesis are relevant to practical applications such as industrial discharge in cold lakes: whereas, the laminar flow case relates to laboratory experi- ments which are typically at scales too small for the flow to be turbulent. Previous investigation on warm discharge placed more attention on the biological implications of the spread along the lake bed, and not interested in analysing the dynamics of such flow, which turns out to be our focus. Furthermore, investigations on buoyant plumes that become negatively buoyant at later time (fountain flow) as considered previously, are based on the assumption that density is a linear function of tem- perature: where entrainment always reduces buoyancy. Whereas, the consideration of the temperature of maximum density is crucial and realistic in many practical situations, especially the power station warm discharge. Mixing is then bound to produce a mixture that is denser than both the discharge and the ambient water if receiving water is less than Tm: where this situation differs from plumes with linear mixing properties. Therefore, our focus is to better fathom the behaviour of warm discharge so as to give a detailed description of the flow, and also to observe buoyancy reversal whenever water that is denser than both the discharge and the receiving water is produced. The simulations were carried out for Prandtl number Pr = 7 & 11.4 and over the ranges of Froude number 0.1 ≤ Fr ≤ 5 and Reynolds numbers 50 ≤ Re ≤ 106, with source temperatures that are assumed to be higher than the temperature of maximum density Tm, and the ambient water below the Tm. Our results show some distinct behaviours from those experimental investigations by Bukreev, who also considered warm discharge where water that has temperature above the temperature Tm is initiated into a medium below Tm. The results here also showed some differences from those investigations with the linear dependence relation assumption.

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23

Gigante, Bethany Marie. "SALINE ADAPTATION OF THE MICROALGA Scenedesmus dimorphus FROM FRESH WATER TO BRACKISH WATER". Cleveland State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=csu1382355969.

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24

Dile, Yihun. "Intensifying Agricultural Water Management in the Tropics : A cause of water shortage or a source of resilience?" Doctoral thesis, Stockholms universitet, Stockholm Resilience Centre, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-102878.

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Frequent climatic shocks have presented challenges for rainfed agriculture in sub-Saharan Africa. Appropriate water management practices are among the solutions to the challenges. The role of water harvesting in achieving sustainable agricultural intensification and specified resilience was explored. Suitable areas for water harvesting in the Upper Blue Nile basin were identified. The usefulness of the Curve Number method for surface runoff estimation was evaluated, and was found to perform satisfactorily. The impact of climate change in the Lake Tana sub-basin was studied. A decision support system was developed for locating and sizing of water harvesting ponds in the SWAT model. Methodological developments enabled analysis of the implications of water harvesting intensification in a meso-scale watershed in the Lake Tana sub-basin. Results suggest that water harvesting can increase agricultural productivity, sustain ecosystems and build specified resilience, and thereby contribute to sustainable agricultural intensification. There is considerable potential for water harvesting in the Upper Blue Nile Basin. Rainfall may increase in the Lake Tana sub-basin due to climate change. Supplementary irrigation from water harvesting ponds and better nutrient application increased staple crop production by up to three-fold. Moreover, a substantial amount of cash crop was produced using dry seasonal irrigation. Water harvesting altered the streamflow regime, and reduced sediment loss from the watershed. Water harvesting can play an important role in food security. It showed potential to buffer climatic variability. In the watershed studied, water harvesting will not compromise the environmental water requirements. Instead, increased low flows, and reduced flooding and sediment loss may benefit the social-ecological systems. The adverse effects of disturbance of the natural flow variability and sediment influx to certain riverine ecosystems warrant detailed investigation.

At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 5: Epub ahead of print. Paper 6: Manuscript.

Water resources management and social-ecological resilience

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25

Borghi, A. "HYDROLOGICAL MODELLING FOR THE PREVENTION AND THE MANAGEMENT OF WATER SHORTAGE IN AGRICULTURE". Doctoral thesis, Università degli Studi di Milano, 2017. http://hdl.handle.net/2434/500756.

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In recent decades, frequent and severe droughts have occurred in several countries of the world under nearly all climatic regimes. Since the middle 20th century, drought areas have globally increased, and, more specifically, in southern and central Europe. Drought risk is expected to increase in the near future as a result of the climate change, leading to a decline in precipitation and an increase in air temperatures, and consequently in evapotranspiration rates in several regions, including southern Europe and the Mediterranean region. Droughts can significantly affect the agricultural sector since they provoke losses in crop yields and livestock production, increased insect infestations, plant diseases and wind erosion. Moreover, low rainfall during the growing season may affect irrigated agriculture over subsequent years, as a result of low levels of water in reservoirs and groundwater aquifers. In Europe, the monitoring and assessment of drought is entrusted to the European Drought Observatory (EDO), that applies a multi-indicator approach, based on earth observations (EOs) and hydrological modelling data. EDO indicators are computed considering rainfed agriculture, predominant in middle and northern Europe, and are produced on a 5 km grid. In southern Europe, however, the implementation of drought-coping measures (irrigation) can partially or completely alleviate the impacts of potentially severe droughts. Therefore, for these conditions, specific water scarcity indicators explicitly considering irrigation among the water inputs to agro-ecosystems need to be developed and adopted to inform and support stakeholders and decision makers of irrigated regions. In this context, the main objective of the Ph.D. thesis is the presentation of the Transpirative Deficit Index (TDI), a newly developed indicator for the monitoring and the management of Water Scarcity and Drought phenomena based on the use of hydrological modelling, applied at a spatial scale of interest for end-users (250 m grid) and suited for the assessment of water scarcity and drought in Italy as well as in other southern European countries. In particular, TDI was developed as a new module integrated into the spatially distributed hydrological model IdrAgra, and in the Ph.D. research it was tested over the Irrigation District of Media Pianura Bergamasca (IDMPB), considering a simulation period of 22 years (1993-2014) and subdividing the territory by means of a grid with cells of 250 m×250 m. As a first step in the thesis, D TDI was described as an agricultural drought index focusing on overcoming the limitation of other approaches, not taking into account with sufficient detail land cover and soil properties. The D TDI is based on the calculation of the spatially distributed actual transpiration deficit, to determine the level of drought experienced by crops within the single model cells; thus, it can provide a much more accurate measure of agricultural drought at the irrigation district scale than the one that could be achieved through meteorological drought indices such as SPI or SPEI. The auto-correlation analysis of D-TDI showed to be positive with a persistence of 30 days for the two more widespread crops in the study area, maize and permanent grass. The analysis demonstrated also that soils characterized by a high available water content can more easily compensate dry spells. Finally, a positive significant correlation between D-TDI and SPI was observed for maize, with a persistence of 40 days, while no correlation was observed for permanent grass, probably related to cutting cycles, that could mask the relation between storage capacity and short-time variability of the meteorological conditions. Successively, a methodology to compute crop yield using moderate spatial and temporal resolution Earth Observation (Landsat) data was set. In particular, the developed procedure, based on the integration of the Available Photosynthetically Active Radiation over the growing season, showed that statistical inventories and satellite data can be integrated to produce annual spatially distributed estimates of cropland productivity, while site-specific observational field data can be used to validate the relationship between APAR and productivity for specific crops (i.e. maize in this Ph.D. research). A phenological parameter extraction algorithm was developed to derive key phenology stages for the maize crop. However, the results presented in the study showed two main weaknesses: (1) cloud cover and noise in the original Landsat dataset were not appropriately removed by the Whittaker algorithm, and (2) SOS (Start of Season) and EOS (End of Season) extracted from satellite data were underestimated for a discrete numbers of fields with respect to observed ground-truths, probably as a consequence of the method adopted for setting the thresholds. A crop specific light use efficiency (ε_b^*) was estimated as the ratio between the average maize yield over the study period taken from Regional Statistic Inventory (Regional Authority and ISTAT), and the average APAR value calculated for the maize pixels over the same spatial extension and time period. The εb* estimated value fell within the range of the coefficients calibrated with other satellite-based algorithms. Finally, TDI was applied as a water scarcity index (WS-TDI), thus including water availability for irrigation within the inputs of the IdrAgra model. The behaviour of D-TDI and WS-TDI was compared over the same area, analysing their spatialized trend in response to varying meteorological conditions, and in particular considering drought events and dry spells. The two indices proved to be suitable to monitor agricultural drought and water scarcity over a territory, and helped in identifying drought and/or water scarcity prone sub-districts, as a function of crop, soil type and water availability. Both D-TDI and WS-TDI could therefore be used as operational indicators to produce periodic maps that could help farmers and irrigation district managers in coping with agricultural drought and water scarcity and, eventually, in setting up proper adaptation measures. In particular, in case of availability of real time meteorological data and water discharges at the main surface water diversions, the indicators may be adopted by an authority responsible for the monitoring of the state of agriculture (ERSAF or ARPA in the Lombardy region) to promptly inform (through newsletters or a web site) stakeholders on the agricultural drought/dry spells and water scarcity/shortages phenomena evolution. Additionally, the indicators may be adopted in climate change studies, allowing to visualize the evolution of drought and water scarcity phenomena over the territory, as a consequence of changes in meteorological forcing and in the availability of water by irrigation sources. Finally, they could be used as useful tools to support planning decisions on water resources allocation or action plans to reduce water consumptions in specific portions of the territory (e.g. conversion of irrigation methods, introduction of different crop species, etc.), also in view of an adaptation to the climate change. WS TDI maps over a pilot study area were statistically compared with the maize yield maps derived from EO data (Landsat dataset): an ensemble correlation analysis proved a positive correlation between the two variables.

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26

Richardson, Glen. "Climate response to fresh water forcing in the Southern Ocean". Thesis, University of East Anglia, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.432442.

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Andreasson, My. "Emergency Water Planning and the Issues with making Drinking Water Accessible for Everyone". Thesis, Umeå universitet, Kulturgeografi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-149616.

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In Sweden, the access to drinking water is something that often is taken for granted. But several incidents where regions have found themselves without drinking water shows that we should be more concerned about crisis management concerning drinking water. Regulations state that even in a situation with drinking water disturbance the municipality is responsible for providing all citizens with drinking water of acceptable quality. When drinking water is not delivered in regular pipelines it is called emergency water, which is an alternative way to distribute drinking water within the region. During a crisis it is important that the authorities can act quickly in order to minimize the consequences that will occur if a region is without drinking water. The National Food Agency (Livsmedelsverket) have therefore developed a guide for municipalities how to make an emergency water plan. It contains information of how to map and prioritize water users. This is a case study of Nordmaling Municipality that investigates how and why water users should be prioritized during a disturbance in drinking water. The aim has also been to locate emergency water containers for citizens and study the accessibility of these locations and the level of justice within the society connected to citizens (in)accessibility. In order to do this study, the guide from the National Food Agency have been studied along with consultation with the municipal administration. Then a quantitative Multi Criteria Analysis (MCA) in GIS has been performed in order to find “optimal” locations for emergency water resources. Recommendations from the National Food Agency have been followed within the frame, ability and visions of Nordmaling Municipality. The study displays the functions that will obtain emergency water, and recommendations and regulations behind the decisions. Along with 12 different locations which have been decided based on results from the MCA. Water users (with extra consideration to vulnerable water users) living outside of the geographical “catchment-area” of a location with emergency water have been studied. This has shown that the locations are not accessible for everyone within the municipality. Constrained accessibility can be seen especially for elderly and those living in the sparsely parts of Nordmaling, which displays an unjust society.

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28

Machethe, Elliot Masoto. "The causes and impact of water shortage on the households of Ga-Kgapane Township in the Limpopo Province". Thesis, University of Limpopo (Turfloop Campus), 2011. http://hdl.handle.net/10386/677.

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Thesis (M.Dev.) --University of Limpopo, 2011
Water shortage is a global problem. While other people in some parts of the world maybe enjoying enough supply of water others are faced with water shortage. South Africa is not an exception in this regard because some do not have access to water but rely on distance conveyance. Government is under constitutional obligation to supply this basic social and economic service. This study, therefore, aimed at investigating the causes of water shortage and the impact thereof on the household of Ga-Kgapane Township in Limpopo Province. This township falls under Greater Letaba Municipality in Modjadjiskloof. The data collected from four sections/localities of this Township showed that the area has a serious problem of water shortage. The lack of water according to the findings negatively affects the livelihoods and development of the people of Ga-Kgapane Township.

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29

Drysdale, Lewis A. "Arctic fjords : simplified modelling and the role of freshwater". Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=237133.

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Defining the role of freshwater in a fjord is important to further the understanding of seasonal physical variability in fjordic systems because the variability of freshwater flux is a key control on fjord oceanography, yet information on freshwater inputs to Svalbard fjords is currently lacking. In this study, two methods of studying fjords are utilised. Firstly, seawater samples and oceanographic profiles were collected from four fjords and shelves around the high-Arctic Svalbard archipelago between September 2013 and April 2015. Analysis of the seawater samples showed that surface meteoric water in a glaciated west-Svalbard fjord was present in quantities up to four times as much (∼18%) assea-ice melt (∼5%). In comparison, a north-Svalbard fjord had more than twice as much sea-ice melt (∼5%) as meteoric water (∼2%). Four contrasting regions of freshwater infuence around the Svalbard archipelago were established, defined by their freshwater processes. Further analysis of data suggest that coastal currents act as an upstream freshwater source, and are also enhanced by freshwater along their path. Upper layer circulation, meanwhile, was seen to be an important mode of dispersal of freshwater inputs from smaller inlets. Secondly, a box model was modified by the inclusion of a sea ice model and was run to understand the leading-order processes and mechanisms observed in Arctic fjords. Model results were successfully validated against four years of oceanographic data from a mooring deployed between 2008–2013 in a restricted exchange fjord on Svalbard and represented the seasonal cycle of a high-Arctic fjord including sea-ice growth and convection. The model showed that varying the sill geometry of a high-Arctic fjord impacts the formation of sea-ice and the dominant modes of exchange. The model also showed that warming of the sub-surface temperature causes excess heat inside fjords, which impacts on sea-ice production and (although not shown) is highly likely to cause accelerated melting of tidewater glaciers.

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30

Bailey, Eva Machelor. "Processes Affecting Macroalgal-Seagrass Dynamics in the York River, Virginia". W&M ScholarWorks, 1998. https://scholarworks.wm.edu/etd/1539617969.

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Ledwin, Jane M. "Sedimentation and its Role in the Nutrient Dynamics of a Tidal Freshwater Marsh". W&M ScholarWorks, 1988. https://scholarworks.wm.edu/etd/1539617586.

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32

Galler, John J. "Medium- and Long-Term Changes in Fluvial Discharge to the Sea: The Yellow River Case Study". W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539617746.

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33

Wooden, Eric Anthony. "Tidally Driven Patterns of Nekton Distribution and Utilization of a Tidal Freshwater Marsh at Morris Creek (Chickahominy River, Virginia)". W&M ScholarWorks, 1999. https://scholarworks.wm.edu/etd/1539617979.

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34

Mahon, Susan Alexandra. "Distribution of Freshwater Amphipoda in the Lake Matoaka/College Woods Area, Williamsburg, Virginia". W&M ScholarWorks, 1997. https://scholarworks.wm.edu/etd/1539626095.

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35

Zehmer, John Kinsley. "Calcium as a Limiting Factor in the Distribution of the Amphipod Gammarus pseudolimnaeus". W&M ScholarWorks, 1998. https://scholarworks.wm.edu/etd/1539626165.

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36

Fairman, Christy Michelle. "Using an Occupancy Modeling Framework to Test the Effects of Habitat Variables on Pond Occupancy of Mabee's Salamander (A mabeei) and Marbled Salamander (A opacum)". W&M ScholarWorks, 2009. https://scholarworks.wm.edu/etd/1539626882.

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37

Postaski, Lindsey L. "Life History and Ecology of the Freshwater Amphipods Gammarus pseudolimnaeus and Gammarus fasciatus in Southeastern Virginia". W&M ScholarWorks, 2012. https://scholarworks.wm.edu/etd/1539626926.

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38

Neubauer, R. Joseph. "The Relationship between Dominant Macrobenthos and Cyclical Hypoxia in the Lower York River". W&M ScholarWorks, 1993. https://scholarworks.wm.edu/etd/1539617659.

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39

Packett, Carmen Rebekah. "Effects of Salinity and Nitrogen on the Distribution and Growth of Phragmites australis along the Rappahannock River". W&M ScholarWorks, 2005. https://scholarworks.wm.edu/etd/1539626837.

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40

Reay, William G. "Subsurface Hydrodynamics and Nutrient Exchange within an Extensive Tidal Freshwater Wetland". W&M ScholarWorks, 1989. https://scholarworks.wm.edu/etd/1539617595.

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Located between upland and riverine systems, extensive tidal freshwater wetlands are influenced by a variety of recharging water sources and their respective nutrient contents. Conversely, tidal wetlands discharge interstitial waters and solutes to surface waters during periods of aerial exposure. Geohydrologic and model simulation methodology were utilized in order to aid in the understanding of wetland subsurface flow dynamics, its influence upon pore water nutrient chemistry, and its role in nutrient exchange with adjacent surface waters. Interstitial water nutrient chemistry was monitored along three transects extending from the uplands to the creekbank edge. Surface waters were also monitored throughout the 13 month study period. Measurements of soil dry bulk density, percent organic matter, fiber content, and horizontal hydraulic conductivity were conducted along a 118 meter transect from the creekbank edge to the high marsh/upland interface. Results indicate vertical and lateral heterogeneity of these physical and hydraulic soil properties within the upper one meter soil profile. Multivariate statistical techniques best described the transect as four separate soil types. General regions of soil types followed wetland elevational regions, these include: the creekbank, levee, low marsh flat, and high marsh regions. Fiber content was identified as the measured parameter which best explained variations in wetland soil permeability. Vertical and horizontal hydraulic head fluctuations were monitored utilizing piezometer/well arrays along the 118 meter transect. Direct measurement of interstitial water seepage flow from the subaquaeous portion of the creekbank to adjacent surface water was determined. Model simulation of subsurface hydrodynamics were made in order to provide water table fluctuations, estimates of horizontal seepage, and pore water budgets along the transect. Field measurements of marsh surface elevations and hydraulic soil properties were incorporated into the model to allow for comparison between simulated and observed results. Spatial variations in soil properties, and subsurface hydrodynamics indicate that an extensive tidal freshwater wetland cannot be considered as a homogeneous unit. It may be described more accurately as three distinct, yet interactive regions (creekbank, low marsh flat,and high marsh), with varying potentials for surface and interstitial water exchange. The creekbank, experiencing large water table oscillations and hydraulic gradients, was the most dynamic and tidally influenced region. These hydrodynamic characteristics resulted in substantial subsurface water transport and dilution of interstitial waters by recharging surface waters within the creekbank region. Due to extremely low hydraulic gradients and ponding of water, horizontal seepage was minimal within the low marsh flat. Moderate hydraulic gradients in conjunction with highly permeable soils were conducive for significant horizontal seepage within the high marsh. Hydrologic evidence indicates a potential for nutrient rich shallow groundwater recharge within the high marsh region. Sensitivity analysis within the creekbank region indicates that aquifer depth exhibits the largest influence on interstitial water discharge followed by soil permeability and specific yield properties of the aquifer respectively. Inverted results, as those found within the creekbank region, were obtained for the high marsh region. Interstitial water nitrogen and total phosphorus levels were variable and a function of depth, location, and time. However, several generalities and patterns appeared relatively consistant. Creekbank pore waters were relatively enriched with oxidized inorganic forms of nitrogen relative to low and high marsh regions. Creekbank ammonium, total nitrogen and phosphorus interstitial pools were intermediate, whereas, dissolved organic nitrogen levels was the lowest of the three regions sampled. The low marsh flat was inorganic nitrogen poor, and intermediate with respect to dissolved organic nitrogen, relative to creekbank and high marsh regions. Pore waters within the low marsh were significantly enriched with dissolved total phosphorus as compared to the creekbank and high marsh regions. High marsh interstitial waters displayed reduced levels of nitrate and nitrite, while levels of ammonium, dissolved organic and total nitrogen were elevated in relation to the creekbank and low marsh flat. Interstitial total phosphorus levels within the high marsh were significantly lower than the low marsh and approximately equal to the creekbank region. The role and influence of subsurface hydrodynamics upon pore water nutrient concentrations and spatial variations are discussed. Spatial and temporal potential patterns of nutrient exchange between surface water and pore waters of various wetland regions are identified. Dissolved oxidized inorganic forms of nitrogen were imported throughout the sampling period by the creekbank, low marsh flat, and high marsh regions. Ammonium flux, due to seepage , was predominantly from the wetland to surface waters; the high marsh exhibited a greatest potential for ammonium export. The high marsh was a source of dissolved organic nitrogen throughout the study, while the low marsh flat and creekbank regions may best be characterized as sources during winter, spring, and summer months, and potential sinks during the fall. The high marsh exhibited the potential to export dissolved total nitrogen throughout the year, whereas, the low marsh flat and creekbank exhibit export potential during spring and summer months. Patterns of total phosphorus exchange were from high marsh, and low marsh regions throughout the year, while exchange between creekbank and surface waters was minimal and temporally variable. Hydrodynamics within each wetland region must be considered in conjunction with pore water chemistry, in order to fully understand nutrient and solute transport potentials.

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41

Shields, Erin C. "Influences of Habitat Conditions on Submerged Aquatic Vegetation Development in the Chickahominy River and Other Virginia Tributaries of the Chesapeake Bay". W&M ScholarWorks, 2008. https://scholarworks.wm.edu/etd/1539617869.

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Recently, there has been an expansion of submerged aquatic vegetation (SAV) in the tidal fresh and oligohaline portions of lower Chesapeake Bay tributaries. Much like the resurgence seen in the Potomac in the 1980’s, this spread of SAV in Virginia systems such as the Mattaponi, Pamunkey and Chickahominy seems to have been initiated by the introduction and spread of the invasive species Hydrilla verticillata, and appears to have been rapid. However the resurgence in the Piankatank has occurred in the absence of the introduction of this species. The factors that are influencing the growth of SAV in these tributary environments, including water quality and habitat conditions as well as the potential for interspecific competition between H. verticillata and the other SAV species in these regions are not well known. Annual aerial mapping surveys of the Chickahominy River were used alongside historical water quality data to investigate the patterns and rates of SAV bed development, and the relationships between this development and water quality conditions. Field investigations were performed in order to better understand the seasonal community dynamics relative to water quality conditions and interspecific competition. Historical analysis, field monitoring and field experimentation all showed salinity and turbidity to be the main factors controlling SAV abundance and species distribution along the Chickahominy River. Historical analysis of the Chickahominy River revealed a decline in SAV abundance in 2002, which corresponded with seasonal mean salinities of 4.1 psu. SAV abundance from 1998-2007 showed a significant correlation with vegetation emergence period secchi depth, in which secchi depths of 0.3 meters, the lowest of the time period, occurred during the 2002 SAV decline. Field data showed species zonation, in which H. verticillata was the overall dominant species, but was limited to the upper portion of the river where salinity intrusion remained below 2 psu throughout the growing season. Najas minor was dominant in the lower portion of the river where salinities reached over 4 psu in October. Salinity was the best predictor for H. verticillata’s biomass difference between the upper and lower river. SAV in the Chickahominy was able to grow in a wide range of conditions, with total suspended solids and chlorophyll a concentrations at times greater than 20 mg l-1 and 40 μg l-1, respectively, and sediment organic content ranging from less than 1% to greater than 25%. Comparisons with the Mattaponi and Piankatank rivers revealed ideal habitat for H. verticillata growth in the Mattaponi, where salinities along the vegetated reach of the upper river did not extend above 1 psu. On the other hand, this species was not found growing in the Piankatank, where salinities in the very upper portion of the river reached 3.5 psu. Finally, a field species removal experiment demonstrated that environmental conditions rather than interspecific competition were most important in determining plant performance, as both H. verticillata and N. minor exhibited poor growth in the lower river site, which had higher salinity and turbidity levels than the upper river site.

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42

White, Kasondra Victoria. "Water, equity, and the rural consciousness : an agricultural response to water shortage in the Okanagan Valley of British Columbia". Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/9410.

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The combined effects in the Okanagan Valley of rapid population growth, climate change, and an environment that is naturally hot and dry are expected to exacerbate the region‘s already limited water supplies to a point where critical water shortages could occur within the foreseeable future. This issue is particularly relevant within the agricultural sector, as the water that has been allocated for irrigation in the valley may not be available if increasingly dominant urban demands impinge on farm requirements. Based upon an extensive series of interviews and a focus group session with Okanagan irrigators, this thesis documents current water use patterns, as well as agricultural perceptions surrounding the factors that contribute to both present and anticipated water shortages in the valley. Insight gained from this research has also been applied to an evaluation of various water shortage adaptation options. In particular, water trading and collaborative approaches to water management have been assessed for their acceptability and appropriateness within the Okanagan Valley. This discussion has been placed within the context of sustainable development theory and political ecology, which together demand a consideration of the ways that policies and management regimes may disproportionately impact upon various stakeholders and the natural environment, in positive and negative ways. Drawing upon this framework, it has been concluded that the preferences of Okanagan irrigators surrounding water shortage adaptation options are affected by the presence of a number of conditions that are seen as threatening agricultural viability in the valley. In light of this, opinions surrounding the usefulness of water trading and collaborative management are often based upon a desire to iii preserve the agricultural base in the Okanagan, while also balancing environmental and essential domestic requirements.

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43

Parmenter, Graeme. "The effect of soil water shortage on ryegrass and white clover growing in mixtures". Thesis, University of Reading, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.278085.

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44

Gregory, Lisa Gayle. "Characterisation of nitrate respiring bacterial populations in a fresh-water sediment". Thesis, University of East Anglia, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323390.

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45

Swift, Thomas. "Smart polymers for the detection of polymeric contamination in fresh water". Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/6153/.

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The feasibility of using reversible complexation between labelled poly(acrylic acid) and poly(acrylamide) as a low concentration detection method for industrial flocculants has been investigated. Aromatic labels acenaphthylene and 9-anthryl methyl methacrylate have been added to polymer chains to model the behaviour of these polymers in dilute aqueous solutions, demonstrating a molecular weight dependency of the conformational change of poly(acrylic acid). It is shown that interpolymer complexation can be observed via a dramatic rise in anisotropy of a singly labelled sample. Using a single exponential system to model the data a clear concentration gradient can be created, showing the ratio between probe polymer and detected species. This system is robust against a range of salts and other water impurities and other polymers capable of bonding to poly(acrylic acid) have also been investigated. Chains of poly(acrylic acid) were grafted onto solid surfaces in a preliminary investigation into whether it would be possible to integrate this detection system with a reusable solid substrate. Two methods were investigated: ceric ammonium nitrate initiated grafting and reversible addition-fragmentation chain transfer copolymerisation.

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46

Mayakoti, Amukta. "Characterization of Fresh Water Microalgae from East Tennessee for Biodiesel Production". Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/etd/1426.

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There is an increasing need for renewable energy sources to replace fossils fuels which accumulate harmful byproducts in the environment. Biodiesel emits less gaseous pollutants than diesel. There are various sources for biodiesel but they are unable to meet the existing demands for fuel. Microalgae are a promising source for biodiesel because of its relatively faster growth rate, availability, and lipid content. Microalgae (JC and BT) growing in local water bodies were collected, selected on section media containing antibiotics, and used for characterizations. Experiments were conducted to study and evaluate the optimum growing conditions. Results show that both JC and BT attain maximum growth with shaking and additional aeration compared to control microalgae Dunaliella salina, Nannochlorposis oculata which do not require additional aeration for optimal growth. Lipid extraction results suggest that JC (9.7%) and BT (4.1%) have slightly higher lipid content compared to control algae e.g. Chlamydomonas reinhardtii (3.1%).

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47

McInnes, Sandra J. "Taxonomy, biodiversity and biogeography : Tardigrada and Antarctic meiofauna". Thesis, Anglia Ruskin University, 2010. http://arro.anglia.ac.uk/216030/.

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The main subject of my papers has been the phylum Tardigrada, with particular emphasis on the Antarctic fauna. While this is one of the ‘lesser known phyla’ the group forms an important element of Antarctic non-marine ecosystems. My work has centred on four interrelated themes: i) taxonomy, predominantly Tardigrada and with an Antarctic bias though including wider global species and high taxon groupings (I have also worked on other taxa such as Fungi-imperfecti and freshwater invertebrates); ii) biodiversity of tardigrades, particularly Antarctic habitats; iii) data-based studies based on the terrestrial Tardigrada and Antarctic freshwater crustaceans; and iv) biogeographic analysis of these databases. The thesis presented consists of papers published in major, peer-reviewed journals, along with book chapters published and in press. Several of my papers have been cited 10-30 times according to the ISI Web of Science citation system. Highlights of my work include being the first to publish a paper on the global terrestrial biogeography of a phylum and showing the extant limno-terrestrial tardigrade fauna reflect the early tectonic break-up of the Laurasia, West and East Gondwana super continents between 65 and 135 million years ago.

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48

McInnes, Sandra J. "Taxonomy, biodiversity and biogeography: Tardigarda and Antarctic meiofauna". Thesis, Anglia Ruskin University, 2010. https://arro.anglia.ac.uk/id/eprint/216030/1/McInnes_Thesis_2010.pdf.

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The main subject of my papers has been the phylum Tardigrada, with particular emphasis on the Antarctic fauna. While this is one of the ‘lesser known phyla’ the group forms an important element of Antarctic non-marine ecosystems. My work has centred on four interrelated themes: i) taxonomy, predominantly Tardigrada and with an Antarctic bias though including wider global species and high taxon groupings (I have also worked on other taxa such as Fungi-imperfecti and freshwater invertebrates); ii) biodiversity of tardigrades, particularly Antarctic habitats; iii) data-based studies based on the terrestrial Tardigrada and Antarctic freshwater crustaceans; and iv) biogeographic analysis of these databases. The thesis presented consists of papers published in major, peer-reviewed journals, along with book chapters published and in press. Several of my papers have been cited 10-30 times according to the ISI Web of Science citation system. Highlights of my work include being the first to publish a paper on the global terrestrial biogeography of a phylum and showing the extant limno-terrestrial tardigrade fauna reflect the early tectonic break-up of the Laurasia, West and East Gondwana super continents between 65 and 135 million years ago.

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49

Charles, Sean P. "The Development of Ecological Functions in Created Forested Wetlands". W&M ScholarWorks, 2013. https://scholarworks.wm.edu/etd/1539617942.

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Wetland mitigation has become a 2.4 billion dollar per year industry in the U.S. and in Virginia it leads to the replacement of 77 ha of palustrine forested wetlands (PFWs) per year with mitigation wetlands, including created forested wetlands (CFWs). Mitigation hinges on the idea that compensation wetlands lead to “no net loss of wetland function” when compared to impacted wetlands. We assessed the functions of provision of habitat and biogeochemical functions associated with production of biomass, the retention and removal of nutrients and the accumulation of soil C over 8 years in seven CFWs of approximately 11 and 20 years and compared them to natural reference wetlands (NRWs). CFW plant communities were similar to NRWs in all measured parameters in the herbaceous and shrub/sapling strata and in all strata combined. However, non-native dominance showed a significant positive linear relationship with CFW age. In the tree strata, 11 year old (yo) CFWs had lower richness than NRWs and both age classes of CFWs had lower FQI than NRWs. NRWs held 10 to 20 times more carbon in woody biomass than CFWs. Tree species composition was significantly different between CFWs and NRWs, however NRW trees were similar to CFW saplings. 11 yo CFWs held lower percentages of C, N and P and had higher Db than NRWs in both the 0-10 and 10-20 cm depth. 20 yo CFWs developed similar levels of %C, %P, bulk density (Db), and nutrient ratios in the surface and displayed rapid increases in %C and %N over 8 years. However, CFWs offered 45% lower soil total soil C storage and 50% lower %N. Furthermore, all CFWs stored lower nutrient levels than NRWs in the 10-20 cm soil depth. We found that FQI correlated positively with total C accumulation rates in woody biomass and soil C, indicating that biogeochemical function and the provision of habitat can be complimentary in CFWs. Finally, 11 and 20 yo CFWs adhered to the regulatory performance standards established for Virginia in terms of stems per ha and wetland indicator status, but all wetlands (including NRWs) failed to achieve <5% non-native species cover.

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50

Bradley, Cassie D. "The Impacts of Shoreline Development on Shallow-Water Benthic Communities in the Patuxent River, MD". W&M ScholarWorks, 2011. https://scholarworks.wm.edu/etd/1539617905.

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Natural coastal habitats throughout Chesapeake Bay are increasingly threatened with shoreline modification due to population growth and rising rates of development. The replacement of these natural coastlines with hardened structures such as seawalls (bulkheads) and stone revetments (riprap) not only compromises vegetation at the land-water interface, but also can influence several elements of local aquatic food webs. Effects of these alterations have been well-studied with respect to fish assemblages and intertidal communities, particularly in conjunction with larger-scale watershed development, and recently, interest has shifted toward investigation of the effects of shoreline development on subtidal benthic infaunal communities.This study evaluated the direct, local impacts of bulkhead and riprap compared to natural marsh shorelines, as well as the effects of sediment characteristics, predator abundance, and system-specific physical features on benthic infauna in the Patuxent River, Chesapeake Bay. Forty-five sites were divided among three shoreline types and distributed across three main river zones. At each site, a benthic infaunal suction sample (3-mm mesh), push-core sample (500-μm mesh), sediment samples, water-quality measurements, and trawls for predators were taken. Samples were sorted to determine density, diversity, and biomass of infaunal organisms. Data were assessed using an Information-Theoretic approach (AIC analysis) to determine the most influential variables, of those measured, on the infaunal community for two benthic data sets: 3-mm-suctions and 500-μm-cores. Results from these analyses on 3-mm samples suggested that shoreline type was the best predictor of diversity, while wave energy, sediment chlorophyll concentration, sediment type, and predator abundance best predicted density and biomass. Benthic responses within the 500-μm dataset were not strongly affected by shoreline type. Rather, responses were best predicted by sediment chlorophyll, wave energy, sediment type, predator abundance, and sediment organic carbon (TOC) content.Results indicate that, compared to other Bay tributaries, the Patuxent River is a relatively degraded system. The small range in long-term responses of Patuxent infauna from previous work provides a possible explanation as to why I was unable to see significant differences in infaunal response among shoreline types in the current study (i.e., there was little scope for change by shoreline in the system as a whole). However, I suggest that natural marsh habitats are healthier subsystems of the Patuxent River, due to the greater variety of infaunal feeding guilds and higher infaunal biomass observed at these compared to hardened sites. Higher predator abundance was associated with higher infaunal biomass at natural marsh sites in both size fractions, suggesting the bottom-up control of higher-trophic-level species in this system, as predators seek out suitable prey items. Given these observations, and the fact that influential variables such as wave energy, sediment nutrient and chlorophyll content, predator abundance, and sediment type may vary according to shoreline type, the replacement of natural shoreline with hardened structures will lead to complex changes in subtidal benthic communities in Chesapeake Bay tributaries and should be minimized to maintain qualities of the natural system.

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