Дисертації: "Water resources and environmental modelling"

1

Huang, Shaochun. "Modelling of environmental change impacts on water resources and hydrological extremes in Germany." Phd thesis, Universität Potsdam, 2012. http://opus.kobv.de/ubp/volltexte/2012/5974/.

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Water resources, in terms of quantity and quality, are significantly influenced by environmental changes, especially by climate and land use changes. The main objective of the present study is to project climate change impacts on the seasonal dynamics of water fluxes, spatial changes in water balance components as well as the future flood and low flow conditions in Germany. This study is based on the modeling results of the process-based eco-hydrological model SWIM (Soil and Water Integrated Model) driven by various regional climate scenarios on one hand. On the other hand, it is supported by statistical analysis on long-term trends of observed and simulated time series. In addition, this study evaluates the impacts of potential land use changes on water quality in terms of NO3-N load in selected sub-regions of the Elbe basin. In the context of climate change, the actual evapotransipration is likely to increase in most parts of Germany, while total runoff generation may decrease in south and east regions in the scenario period 2051-2060. Water discharge in all six studied large rivers (Ems, Weser, Saale, Danube, Main and Neckar) would be 8 – 30% lower in summer and autumn compared to the reference period (1961 – 1990), and the strongest decline is expected for the Saale, Danube and Neckar. The 50-year low flow is likely to occur more frequently in western, southern and central Germany after 2061 as suggested by more than 80% of the model runs. The current low flow period (from August to September) may be extended until the late autumn at the end of this century. Higher winter flow is expected in all of these rivers, and the increase is most significant for the Ems (about 18%). No general pattern of changes in flood directions can be concluded according to the results driven by different RCMs, emission scenarios and multi-realizations. An optimal agricultural land use and management are essential for the reduction in nutrient loads and improvement of water quality. In the Weiße Elster and Unstrut sub-basins (Elbe), an increase of 10% in the winter rape area can result in 12-19% more NO3-N load in rivers. In contrast, another energy plant, maize, has a moderate effect on the water environment. Mineral fertilizers have a much stronger effect on the NO3-N load than organic fertilizers. Cover crops, which play an important role in the reduction of nitrate losses from fields, should be maintained on cropland. The uncertainty in estimating future high flows and, in particular, extreme floods remain high due to different RCM structures, emission scenarios and multi-realizations. In contrast, the projection of low flows under warmer climate conditions appears to be more pronounced and consistent. The largest source of uncertainty related to NO3-N modelling originates from the input data on the agricultural management.
Wasserressourcen werden in Quantität und Qualität von Veränderungen in der Umwelt, insbesondere von Änderungen des Klimas und der Landnutzung, in signifikantem Maße beeinflusst. In dieser Arbeit wurden die Auswirkungen von Klimavariabilität und Klimawandel auf die Wasserressourcen und Extremereignisse wie Hoch- und Niedrigwasser in Deutschland untersucht. Die Analyse erfolgte auf der einen Seite modellgestützt, wobei die Ergebnisse aus verschiedenen regionalen Klimamodellen durch ein ökohydrologisches Modell in Änderungen in den hydrologischen Prozessen transformiert wurden, zum anderen aber auch datengestützt, z.B. durch die statistische Interpretation von beobachteten und simulierten Zeitreihen. Zusätzlich wurden die Auswirkungen von Landnutzungsänderungen auf Umsatz von Stickstoff in der Landschaft und im Wasser untersucht, wobei dasselbe ökohydrologische Modell zum Einsatz kam. Im Rahmen des Klimawandels wird zur Mitte dieses Jahrhunderts die aktuelle Evapotranspiration in den meisten Teilen Deutschlands mit großer Wahrscheinlichkeit zunehmen. Die täglichen Abflussmengen der fünf größten Flussgebiete in Deutschland (Ems, Weser, Elbe, Obere Donau und Rhein) werden dieser Untersuchung zur Folge im Sommer und Herbst um 8%-30% geringer sein als in der Referenzperiode (1961-1990). 80% der Szenariensimulationen stimmen darin überein, dass die 50-jährigen Niedrigwasserereignisse zum Ende dieses Jahrhunderts mit großer Wahrscheinlichkeit häufiger in den westlichen, den südlichen und den zentralen Teilen Deutschlands auftreten werden. Die gegenwärtige Niedrigwasserperiode (August-September) könnte sich zudem dann bis in den späten Herbst ausweiten. Für alle Flüsse werden höhere Winterabflüsse erwartet, wobei diese Zunahme für die Ems am stärksten ausfällt (ca. 18%). Mit größerer Unsicherheit sind dagegen die Aussagen zur Entwicklung der Hochwasser behaftet. Aus den Ergebnissen, die durch unterschiedliche regionale Klimamodelle und Szenarien getrieben wurden, kann jedoch kein allgemeingültiges Muster für die Änderungen der 50-jährigen Hochwässer ausgemacht werden. Eine optimierte Landnutzung und ein optimiertes Landmanagement sind für die Reduzierung der NO3-Einträge in die Oberflächengewässer essentiell. In den Einzusgebieten der Weißen Elster und der Unstrut (Elbe) kann eine Zunahme von 10% in der Anbaufläche von Winterraps zu einer 12-19% höheren NO3 Fracht führen. Mais, eine weitere Energiepflanze, hat hingegen einen mäßigeren Effekt auf die Oberflächengewässer. Die Höhe der Gabe von mineralischen Düngern beeinflußt zudem in starkem Maße die Nitratbelastung von Flüssen. Zwischenfrüchte können den NO3-Austrag im Sommer zusätzlich erheblich verringern. Insgesamt bleibt die Unsicherheit in der Vorhersage von Spitzenabflüssen und im Besonderen von Extrem-Hochwässern als Folge unterschiedlicher regionaler Klimamodelle, Emissionsszenarien und Realisationen sehr hoch. Im Gegensatz dazu erscheinen die Projektionen zu den Niedrigwasserereignissen unter wärmeren Bedingungen sehr viel deutlicher und einheitlicher. Die größte Unsicherheit in der Modellierung von NO3 dagegen sind die Eingangsdaten z.B. für das lokale landwirtschaftliche Management.

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2

Moulds, Simon. "Toward integrated modelling systems to assess vulnerability of water resources under environmental change." Thesis, Imperial College London, 2016. http://hdl.handle.net/10044/1/45312.

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Land use, land cover and land management change threatens the sustainability of ecosystem services upon which individuals and communities depend. However, quantifying the effects of large-scale environmental change on regional water resources and climate is challenging because of a lack of appropriate data as well as fundamental limitations of environmental models. This thesis focuses on the development of integrated modelling systems for representing feedback mechanisms between human activities and the environment at regional scales. India is selected as a case study because of the unprecedented scale of environmental change in this country over recent decades. Land use change modelling is identified as a viable method for reconstructing historical land use/land cover at regional scales. This is facilitated through the development of a new modelling framework which allows users to perform the entire modelling workflow in the same environment and provides a consistent interface to different spatial allocation models. Hence, the modelling framework enables model intercomparison and ensemble experiments. It furthermore promotes reproducible science because it allows applications to be expressed programmatically. An adapted version of the Change in Land Use and its Effects (CLUE) land use change model is used to reconstruct historical land use/land cover in India between 1956–2010. The model algorithm explicitly accounts for competition between land use/land cover categories as a result of dynamic socio-economic and biophysical conditions. A further dataset showing the irrigated area of various crops is developed by spatially disaggregating historical agricultural inventory data based on maps of cropland extent and biophysical suitability. Land use/land cover maps are supplied to an offline historical simulation of the Joint UK Land and Environment Simulator (JULES), a process-based land surface model, to generate soil moisture values across the Gangetic plain. Simulated soil moisture values are modified to account for the effects of irrigation. The procedure exploits the characteristics of the irrigated area dataset in order to account for the growing season of individual crops. Existing tools for coordinating complex workflows in the hydrological sciences are strongly coupled to underlying modelling frameworks. As a result, they lack flexibility and often necessitate refactoring of the source code of model components. Exploring these issues further, an experiment is devised in which the data processing language R is set up as a workflow orchestration tool for hydrological data analysis and modelling. A new software package implements a set of classes for representing multi-dimensional hydrological data and to provide a common interface to hydrological models. The experimental set-up is demonstrated through two example applications drawn from hydrology and the emerging discipline of socio-hydrology. These serve to highlight the flexibility of the R system for workflow orchestration and model coupling but also draw attention to several areas for future development.

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3

Huang, Shaochun [Verfasser], and Axel [Akademischer Betreuer] Bronstert. "Modelling of environmental change impacts on water resources and hydrological extremes in Germany / Shaochun Huang. Betreuer: Axel Bronstert." Potsdam : Universitätsbibliothek der Universität Potsdam, 2012. http://d-nb.info/1023607468/34.

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4

Hassan, Muhammad. "Exploratory groundwater modelling in data-scarce environments : the shallow aquifer of river Yobe basin, north east Nigeria." Thesis, Cranfield University, 2002. http://dspace.lib.cranfield.ac.uk/handle/1826/11343.

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This thesis addresses the issues of modelling a groundwater system in a data-scarce environment, the Yobe river basin, north east Nigeria. Despite significant investment in the past towards water resources developments, basic data on groundwater resources are limited. Short-term studies by Consultants contain some weaknesses and have not fully investigated the mechanisms of flow to and from the aquifer. Fieldwork studies conducted during this work and in the past (Alkali, 1995) showed that the shallow aquifer system is hydrogeologically complex. Concerns such as the relative magnitudes of recharge mechanisms to the aquifer, hydrologic conditions of the aquifer, a large change in river stage, presence of unconfined 'windows' for vertical recharge, and the fact that the region is located in a semi-arid region need to be addressed. This increased the concerns for the need to explore the system through modelling. Modeling can give insights into the whole system behaviour which other approaches cannot provide. Therefore modelling was carried out and it has provided valuable insights into the complex system. This thesis reports on the procedure of developing a groundwater model that is basic and exploratory based on limited data. Detailed conceptual model was developed using data from previous workers and from a fieldwork undertaken in this study. The conceptual model provided key hydrogeological information on the various physical processes and how they interact with the shallow Fadama alluvial aquifer. It describes the aquifer as around 10 m thick and about 4 km wide with the river partially penetrating it. The aquifer consists of areas that are confined and some that are unconfined. The river is ephemeral and its stage changes rapidly over 4 m. Recharge mechanisms to the aquifer consist of vertical recharge from rainfall and overland flooding through permeable topsoil, river to aquifer flow and 'leakage' through low permeability cover. The conceptual model was idealized and translated into a computational groundwater model using MODFLOW. The model investigated the role of each components of flow in determining the overall water balance of the system. The relationship between river stage and river coefficient in the study of river-aquifer interaction was investigated. Finally the response of the aquifer system to pumping was explored. Groundwater head output from the model was used in the calculation of the various flow components. The main findings and conclusions of the work are that: (i) a comprehensive conceptual model is fundamental in developing a numerical groundwater model; (ii) the exploratory model developed using limited data is plausible because it is hydrologically credible and fits the available data; (iii) the water balance shows that the river to aquifer flow dominates the recharge from rainfall and overland flooding. Contrary to initial belief, the largest river to aquifer flow occurs before the river reaches its peak; (iv) flows between river and aquifer are insensitive to variation of river coefficient with river stage. The limiting factor in the exchange of water between them is the hydraulic gradient and the transmissivity of the aquifer; (v) in representing the river with a constant river coefficient, the coefficient has a threshold value above which the river-aquifer interaction does not change significantly; (vi) over-pumping of the aquifer will decrease river flow to disadvantage of downstream users; (vii) the replenishment of the aquifer can be improved by pumping it at a modest rate.

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5

Barbour, Emily. "Quantitative modelling for assessing system trade-offs in environmental flow management." Phd thesis, Canberra, ACT : The Australian National University, 2015. http://hdl.handle.net/1885/109583.

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This research aims to better enable the management of environmental flows through exploring the opportunities and challenges in using quantitative models for decision making. It examines the development and application of ecological response models, river system models, and multi-objective optimisation for improved ecological outcomes and the identification of trade-offs. In doing so, the thesis endeavours to capture a deeper and more holistic understanding of uncertainty in the application of quantitative models, to assist in making more informed decisions in water resource management. The thesis includes three main components. Firstly, an ecological response model is developed to advance previous methods by: (1) adopting a systems approach to representing water availability for floodplain vegetation, considering rainfall and groundwater in addition to riverine flooding; (2) including antecedent conditions in estimating current ecological condition; and (3) including uncertainty in modelling ecological response through the use of upper and lower prediction bounds and multiple conceptual models derived through expert elicitation. Secondly, the ecological response model is evaluated using sensitivity and uncertainty analysis. Global sensitivity analysis was used to identify model components that are both uncertain and have critical impact on results, and demonstrated that conceptualisation of ecological response had the greatest impact on predicted ecological condition. A novel application of Bayesian analysis was then used to evaluate different expert derived models against observed data, considering multiple sources of uncertainty. The analysis demonstrates a number of remaining challenges in modelling ecological systems, where model performance depends upon assumptions that are highly uncertain. The third and final component evaluates opportunities and challenges in using multi-objective optimisation, to assist in water resource management and the improvement of ecological outcomes. This component begins with a synthesis of previous studies drawing upon literature from hydrology, ecology, optimisation and decision science, and identifies a number of strategies for improvement. The synthesis is followed by a case study on the Lachlan catchment of the Murray-Darling Basin, Australia. The case study uses multi-objective optimisation to explore different environmental flow rules using a river system model combined with the expert-based ecological models. In doing so, it addresses the challenges of objective setting and problem framing in the context of significant uncertainty. The case study evaluates results generated using the optimisation framework in terms of likely actual decision outcomes. The research identifies a need to revisit fundamental questions regarding system understanding and objective framing in the light of rapidly improving computational capacity and sophistication. This is particularly relevant in the case of ecological management, where objectives form an interplay between ecological science and social values. Modelling tools provide valuable pathways to system learning and communication, yet a deeper understanding and evaluation of model behaviour in the context of actual decisions is needed. The methods presented in this thesis aim to provide a step toward addressing the challenges of working with uncertain information, incomplete knowledge, and integration across multiple disciplines within a decision-making environment. Through the methods developed here, the research seeks to advance the science of model development and application.

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6

Tshimanga, Raphael Muamba. "Hydrological uncertainty analysis and scenario-based streamflow modelling for the Congo River Basin." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1006158.

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The effects of climate and environmental change are likely to exacerbate water stress in Africa over the next five decades. It appears obvious, therefore, that large river basins with considerable total renewable water resources will play a prominent role in regional cooperation to alleviate the pressure of water scarcity within Africa. However, managing water resources in the large river basins of Africa involves problems of data paucity, lack of technical resources and the sheer scale of the problem. These river basins are located in regions that are characterized by poverty, low levels of economic development and little food security. The rivers provide multiple goods and services that include hydro-power, water supply, fisheries, agriculture, transportation, and maintenance of aquatic ecosystems. Sustainable water resources management is a critical issue, but there is almost always insufficient data available to formulate adequate management strategies. These basins therefore represent some of the best test cases for the practical application of the science associated with the Predictions in Ungauged Basins (PUB). The thesis presents the results of a process-based hydrological modelling study in the Congo Basin. One of the primary objectives of this study was to establish a hydrological model for the whole Congo Basin, using available historical data. The secondary objective of the study was to use the model and assess the impacts of future environmental change on water resources of the Congo Basin. Given the lack of adequate data on the basin physical characteristics, the preliminary work consisted of assessing available global datasets and building a database of the basin physical characteristics. The database was used for both assessing relationships of similarities between features of physiographic settings in the basin (Chapters 3 and 4), and establishing models that adequately represent the basin hydrology (Chapters 5, 6, and 7). The representative model of the Congo Basin hydrology was then used to assess the impacts of future environmental changes on water resources availability of the Congo Basin (Chapter 8). Through assessment of the physical characteristics of the basin, relationships of similarities were used to determine homogenous regions with regard to rainfall variability, physiographic settings, and hydrological responses. The first observation that comes from this study is that these three categories of regional groups of homogenous characteristics are sensible with regards to their geographical settings, but the overlap and apparent relationships between them are weak. An explanation of this observation is that there are insufficient data, particularly associated with defining sub-surface processes, and it is possible that additional data would have assisted in the discrimination of more homogenous groups and better links between the different datasets. The model application in this study consisted of two phases: model calibration, using a manual approach, and the application of a physically-based a priori parameter estimation approach. While the first approach was designed to assess the general applicability of the model and identify major errors with regard to input data and model structure, the second approach aimed to establish an understanding of the processes and identify useful relationships between the model parameters and the variations in real hydrological processes. The second approach was also designed to quantify the sensitivity of the model outputs to the parameters of the model and to encompass information sharing between the basin physical characteristics and quantifying the parameters of the model. Collectively, the study’s findings show that these two approaches work well and are appropriate to represent the real hydrological processes of Congo Basin. The secondary objective of this study was achieved by forcing the hydrological model developed for the Congo Basin with downscaled Global Climate Model (GCMs) data in order to assess scenarios of change and future possible impacts on water resources availability within the basin. The results provide useful lessons in terms of basin-wide adaptation measures to future climates. The lessons suggest that there is a risk of developing inappropriate adaptation measures to future climate change based on large scale hydrological response, as the response at small scales shows a completely different picture from that which is based on large scale predictions. While the study has concluded that the application of the hydrological model has been successful and can be used with some degree of confidence for enhanced decision making, there remain a number of uncertainties and opportunities to improve the methods used for water resources assessment within the basin. The focus of future activities from the perspective of practical application should be on improved access to data collection to increase confidence in model predictions, on dissemination of the knowledge generated by this study, and on training in the use of the developed water resources assessment techniques.

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7

Crookes, Douglas John. "Modelling the ecological-economic impacts of restoring natural capital, with a special focus on water and agriculture, at eight sites in South Africa." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71628.

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Thesis (PhD)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The restoration of natural capital has ecological, hydrological and economic benefits. Are these benefits greater than the costs of restoration when compared across a range of dissimilar sites? This study examines the impact of restoration at eight case study sites distributed throughout South Africa. The benefits of restoration include improved grazing values and crop yields, improvements in water yield and quality, soil carbon improvements, wild products, lumber, fuelwood and electricity. The impact of restoration on all forms of natural capital (i.e. cultivated, replenishable, renewable and non-renewable) is therefore quantified. The costs of restoration include depreciation on capital expenditure, labour costs, equipment and bond refinancing costs. The literature review done during this study presents three frameworks. The first framework classifies social science using the classification scheme of Burrell and Morgan. It shows that system dynamics modelling and neoclassical economics share the same epistemological and ontological characteristics, both of these fall within the naturalistic paradigm, which also characterises most of scientific research. System dynamics modelling and neoclassical economics, however, digress in the Flood and Jackson classification scheme, which is the second framework for classifying social science. Neoclassical economics is characterised by a small number of elements and few interactions between the elements. Systems dynamics modelling, on the other hand, is characterised by a large number of elements and many interactions between the elements. The nature-freedom ground motive is subject to a number of criticisms, including the fact that it introduces dualistic thinking into the analysis, as well as that it does not adequately address normative or moral issues. The framework of Dooyeweerd, the third framework, is presented as a means of transcending the nature-freedom ground motive. Although the nature-freedom ground motive is largely utilised in this study, the analysis does transcend the traditional economic approach in a number of areas. These include, for example, a focus on transdisciplinary methods, disequilibria, adopting a case study approach, and empirical estimation instead of theoretical models. The restoration case studies in this study are examples of individual complex systems. Eight system dynamics models are developed to model interactions between the economic, ecological and hydrological components of each of the case studies. The eight system dynamics models are then used to inform a risk analysis process that culminates in a portfolio mapping exercise. This portfolio mapping exercise is then used to identify the characteristics and features of the different case study sites based on the risk profile of each sites. This study is the first known application of system dynamics, risk analysis and portfolio mapping to an environmental restoration project. This framework could potentially be used by policymakers confronted with budgetary constraints to select and prioritise between competing restoration projects.
AFRIKAANSE OPSOMMING: Die restorasie van natuurlike kapitaal het ekologiese, hidrologiese en ekonomiese voordele. Maar is hierdie voordele groter as die kostes verbonde aan restorasie wanneer dit oor verskeie ongelyksoortige terreine vergelyk word? Hierdie studie bestudeer die impak van restorasie op agt verskillende studie terreine versprei regoor Suid-Afrika. Die voordele van restorasie sluit die volgende in: beter weiding waardes en oes opbrengste, verbeterde water lewering en water kwaliteit, verbetering van grondkoolstof, wilde produkte, hout, brandstofhout en elektrisiteit. Die impak van restorasie op alle vorme van natuurlike kapitaal (gekultiveerd, aanvulbaar, hernubaar en nie-hernubaar) is daarom gekwantifiseer. Die kostes van restorasie sluit in ‘n vermindering in kapitaal uitgawes, arbeidskoste, toerusting en verband herfinansieringskoste. Die literatuurstudie hou drie raamwerke voor. Die eerste raamwerk klassifiseer sosiale wetenskappe volgens die Burrel en Morgan klassifikasie skema. Dit wys daarop dat dinamiese stelsel modellering en neoklassieke ekonomie dieselfde epistemologiese en ontologiese eienskappe deel; beide val binne die naturalistiese paradigma, wat dan ook meeste wetenskaplike navorsing tipeer. Stelseldinamiese modellering en neoklassieke ekonomie wyk egter af na die Flood and Jackson klassifikasie skema, wat die tweede raamwerk is waarvolgens sosiale wetenskappe geklassifiseer word. Neoklassieke ekonomie word gekenmerk aan 'n klein aantal elemente en 'n beperkte hoeveelheid interaksie. Stelseldinamiese modellering het egter 'n groot aantal elemente met veel meer interaksies tussen hierdie elemente. Die natuur-vryheid grondmotief is onderworpe aan 'n aantal punte van kritiek, insluitende die feit dat dit dualistiese denke in analise inbring. Verder spreek dit ook nie voldoende die normatiewe of morele kwessies aan nie. Die raamwerk van Dooyeweerd, wat dan die derde raamwerk is, word voorgestel as 'n wyse waarop die natuur-vryheid grond-motief getransendeer kan word. Alhoewel die natuur-vryheid grondmotief grootliks gebruik word in hierdie studie, transendeer die analise die tradisionele ekonomiese benadering op 'n aantal gebiede. Hierdie gebiede sluit die volgende in: 'n fokus op transdissiplinere metodes, onewewigtigheid, 'n gevallestudie benadering, en empiriese skatting in plaas van teoretiese modelle. Die restorasie gevallestudies wat in hierdie studie gebruik word is voorbeelde van individuele komplekse sisteme. Agt dinamiese stelsel modelle word ontwikkel om die interaksies tussen ekonomiese, ekologiese en hidrologiese komponente in elke gevallestudie te modelleer. Hierdie agt stelseldinamiese modelle word dan gebruik in 'n risiko analise proses wat uitloop op 'n portefeulje plot oefening. Hierdie portefeulje plot oefening word dan gebruik om eienskappe en kenmerke van verskeie gevallestudie terreine te identifiseer gebaseer op die risiko profiel van elke terrein. Hierdie studie is die eerste bekende toepassing van dinamiese stesels, risiko analise en portefeulje plot tot 'n omgewingsrestorasie projek. Hierdie raamwerk kan potensieël gebruik word deur beleidskrywers wat met begrotings beperkinge gekonfronteer word om tussen restorasie projekte te kies en om hulle te prioritiriseer.

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Emigh, Anthony James. "Predicting floods from space: a case study of Puerto Rico." Thesis, University of Iowa, 2019. https://ir.uiowa.edu/etd/6730.

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Floods are a significant threat to communities around the world and require substantial resources and infrastructure to predict. Limited local resources in developing nations make it difficult to build and maintain dense sensor networks like those present in the United States, creating a large disparity in flood prediction across borders. To address this disparity, I operated the Iowa Flood Center Top Layer model to predict floods in Puerto Rico without relying on in-situ data measurements. Instead, all model forcing was provided by satellite remote sensing datasets that offer near-global coverage. I used three datasets gathered via satellite remote sensing to build and operate watershed streamflow models: elevation data obtained by the Space Shuttle Endeavour through the Shuttle Radar Topography Mission (SRTM), rainfall estimates gathered by a constellation of satellites through the Global Precipitation Measurement Mission (GPM), and evapotranspiration rate estimates collected by Moderate Resolution Imaging Spectroradiometer (MODIS) sensors aboard the Aqua and Terra satellites. While these satellite remote sensing datasets make observations of nearly the entire world, their spatiotemporal resolution is coarse compared to conventional on-the-ground measurements. Hydrologic models were assembled for 75 basins upstream of streamflow gages monitored by the United States Geologic Survey (USGS). Model simulations were compared to real-time measurements at these gages. Continuous simulations spanning 58 months achieve poor Nash Sutcliffe Efficiency and Klinge Gupta Efficiency of -112.0 and -0.5, respectively. The sources of error that influence model performance were investigated, underlining some limitations of relying solely on satellite data for operational flood prediction efforts.

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9

Bohdanowicz, Paulina. "Responsible resource management in hotels : attitudes, indicators, tools and strategies." Doctoral thesis, Stockholm : Department of Energy Technology, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4131.

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10

Chong, Natalie. "Beyond Evidence-Based Decision Support : Exploring the Multi-Dimensional Functionality of Environmental Modelling Tools. Comparative Analysis of Tool." Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC1005.

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À l’heure où les horizons d’une croissance et d’une consommation infinies sont remis en cause, les appels aux développements de solutions de plus en plus robustes, flexibles et intégrées pour gérer les problèmes environnementaux inédits ont conduit à l’avènement d’un nouveau paradigme, transformant de manière radicale les pratiques de la science et de la gestion. L’importance accrue accordée aux approches collaboratives, intégrées et participatives a soutenu l’essor d’arrangements entre science, pratique et politique, tout en rendant nécessaire la création de nouveaux outils pour accompagner la mise en œuvre d’une réglementation de plus en plus exigeante. Dans le contexte de la gestion des ressources en eau, les modèles sont apparus comme des outils cruciaux, plébiscités par des scientifiques et des praticiens, pour leur capacité à faire avancer la compréhension scientifique du fonctionnement des systèmes hydrologiques à renseigner les politiques publiques et la planification de l’eau dans les bassins versants. Une grande diversité d’outils de modélisation a été développée pour analyser les processus physiques, chimiques et biologiques à l’œuvre, à des échelles spatiales et temporelles diverses et avec des degrés de complexité variés. Par ailleurs, les modèles sont censés fournir aux praticiens des outils concrets au service de politiques fondées sur des faits scientifiques (‘evidence-based policy’), en permettant de transposer des problèmes complexes en solutions techniques « gérables ». Pour autant, leur application pratique est loin d’être proportionnelle à l’investissement en temps et en ressources dédié à leur développement. Cette thèse vise à éclairer le fossé persistant entre science, pratique et politique dans le contexte d’un nouveau paradigme pour la science et la gestion, à travers le prisme des outils de modélisation et de leur rôle à l’interface science-pratique-politique. Nous utilisons une approche qualitative et nous nous appuyons sur deux exemples empiriques : le PIREN-Seine en France et le CRC for Water Sensitive Cities en Australie. Bien que les deux exemples partagent des défis, des méthodes et des objectifs similaires, la richesse de leur comparaison repose sur la différence fondamentale dans leurs approches et leurs stratégies.Ce faisant, nous explorons les moteurs, implications et conséquences potentielles des changements de paradigme parallèles à l’œuvre de la science et la gestion, en nous concentrant sur trois aspects : 1/ l’utilisation et l’utilité des outils de modélisation pour soutenir la gestion, la planification et les politiques publiques concernant les ressources en eau ; 2/ les différentes modalités qui permettent d’aborder l’incertitude dans l’aide à la décision reposant sur des modèles ; 3/ la signification ou la portée de nouveaux arrangements entre science, pratique et politique. En retraçant l’histoire de la production et de l’utilisation des outils de modélisation dans les deux exemples, nous cherchons tout d’abord à comprendre la relation nuancée entre « utilisation » et « utilité », en offrant un aperçu des facteurs qui les influencent. Nous nous intéressons ensuite à la question de l’incertitude en analysant la manière dont chercheurs et praticiens affrontent le défi fondamental de l’incertitude dans l’aide à la décision fondée sur les modèles. En considérant les processus complexes, socialement négociés, qui s’inscrivent dans le contexte de la prise de décision, nous nous concentrons sur la construction sociale de l’ignorance et sur sa fonction. Nous examinons enfin, à un niveau macro socio-économique, l’évolution des pratiques engendrée par le changement de paradigme dans la science et la gestion. Parmi ces changements, nous proposons une interprétation de l’émergence et des fonctions des « organisations frontières », et le rôle qu’elles sont amenées à jouer dans la recherche de solutions robustes, flexibles et durables
As the sun sets on the age of unlimited growth and consumption, the call for progressively robust, adaptive and integrated solutions to address ‘wicked’ environmental problems has ushered in a new paradigm that has fundamentally changed the practices of both science and management. Emphasis on collaborative, integrative and participative approaches has given rise to burgeoning science-practice-policy arrangements while necessitating new tools to support the implementation of increasingly demanding regulation. In the context of water resources, models have emerged as fundamental tools favoured by scientists and practitioners alike, owing to their ability to advance scientific understanding of water systems functioning, while at the same time supporting key decisions in the management, policy and planning of river basins. A wide range of modelling tools have been developed to study the numerous physical, chemical, and biological processes at work, on different spatial and temporal scales, with varying levels of complexity. At the same time, models provide practitioners with a practical tool for supporting ‘evidence-based’ policy by transposing complex problems into technical, ‘manageable’ solutions. Yet, their application in practice has proven far from proportional to the amount of time and resources that have been invested in their development.This thesis aims to elucidate the enduring divide between science, practice and policy in the context of a new paradigm of science and management through the lens of modelling tools and their role at the science-practice-policy interface. Using a qualitative approach, we draw from two empirical examples: the PIREN-Seine in France and the CRC for Water Sensitive Cities in Australia. While both share similar challenges, methods and objectives, the fundamental difference in their strategies and approaches offers a rich foundation for comparison. In doing so, we explore the driving forces, implications and potential consequences of the parallel paradigm shifts in science and management, focusing on three main aspects: 1/ the use and utility of modelling tools to support water management, policy and planning; 2/ the different modalities of addressing uncertainty in model-based decision support, and; 3/ the role of new science-practice-policy arrangements. By first retracing the history of production and use of modelling tools in both examples, we seek to understand the nuanced relationship between ‘use’ and ‘utility’, offering insight into influencing factors. Next, we turn to the question of uncertainty by analysing how researchers and practitioners reconcile the fundamental challenge of uncertainty in model-based decision support. Delving deeper into the complex, negotiated social process that comprises the decision-making context, we focus on the social construction of ignorance and its role in decision-making. Finally, we examine the macro-level changes brought about by the paradigm shift in science and management. Amidst these changes, we seek to understand the emergence and functions of ‘boundary organisations’ in this new epoch, and their role in the quest for robust, adaptive and sustainable solutions

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11

James, Tosin. "Changes in Land Use Land Cover (LULC), Surface Water Quality and Modelling Surface Discharge in Beaver Creek Watershed, Northeast Tennessee and Southwest Virginia." Digital Commons @ East Tennessee State University, 2020. https://dc.etsu.edu/etd/3747.

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Beaver Creek is an impaired streams that is not supporting its designated use for recreation due to Escherichia coli (E.coli), and sediment. To address this problem, this thesis was divided into two studies. The first study explored changes in Land Use Land Cover (LULC), and its impact on surface water quality. Changes in E.coli load between 1997-2001 and 2014-2018 were analyzed. Also, Landsat data of 2001, and 2018 were examined in Terrset 18.31. Mann-Whitney test only showed a significant reduction in E.coli for one site. Negative correlation was established between E.coli load, and Developed LULC, Forest LULC, and Cultivated LULC. The second study modelled discharge for Beaver Creek watershed using HEC-HMS. This study simulated discharge in an upstream sub-watershed of Beaver Creek, and the full Beaver Creek with a Nash-Sutcliffe of 0.007, and R2 0.20. Sub-basins with high discharge were identified for further examination for possible high sediment load.

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12

Clare, Evan. "DECOMPOSING A WATERSHED’S NITRATE SIGNAL USING SPATIAL SAMPLING AND CONTINUOUS SENSOR DATA." UKnowledge, 2019. https://uknowledge.uky.edu/ce_etds/87.

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Watershed features, physiographic setting, geology, climate, and hydrologic processes combine to produce a time-variant nutrient concentration signal at the watershed outlet. Anthropogenic influences, such as increased agricultural pressures and urbanization, have increased overall nutrient loadings delivered to the fluvial network. The impact of such increased nutrient loadings on Kentucky’s drinking water remains a potential threat to the region. By coupling spatial sampling of nitrate concentrations in surface water with contemporary nutrient and water quality sensor technology, a decomposition of the Upper South Elkhorn watershed’s nitrate signal and an estimation of source timing and loading in the watershed was completed. The goal of the project was the decomposition of the integrated nitrate signal observed at the outlet of the Upper South Elkhorn watershed into contributing runoff and groundwater sources from agricultural/pasture and urban/suburban land-uses. Decomposing the watershed’s nitrate signal yielded new knowledge learned about nitrate source, fate and transport in immature fluviokarst. This thesis discusses how mean, seasonal, and fluctuating nitrate behavior is related to soil processes, groundwater transfer, streambed removal, and event dynamics. It is expected that the decomposition of the nitrate signal will allow for the targeting of both the timing and sources for nutrient reductions in a watershed.

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13

Aronsson, Johanna. "Användning av tredimensionell geologisk modellering i hydrogeologiska utredningar : En fallstudie inför anläggandet av ett akviferlager i Brunkebergsåsen i Stockholm." Thesis, Stockholms universitet, Institutionen för naturgeografi, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-118515.

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Akviferlager är en form av geoenergi där solenergi lagrad i grundvattnet används för att värma och kyla byggnader. Inför anläggandet av ett akviferlager är det viktigt med grundläggande geologiska och hydrogeologiska utredningar för att säkerställa funktion och kapacitet hos akviferlagret, samt minimera eventuell miljöpåverkan. I denna studie utvecklas en tredimensionell geologisk modell för att öka kunskapen om rullstensåsens geologiska uppbyggnad samt bedöma hur geologin kan komma att påverka det planerade akviferlagret. För att undersöka vilken påverkan manuella justeringar och tolkningar av geologin har, togs två geologiska modeller fram för jämförelse. Utifrån de geologiska modellerna uppskattades effektiv hydraulisk konduktivitet för åsen, d.v.s. sammanlagd konduktivitet för hela akviferens mäktighet, samt transporttid mellan akviferlagrets brunnspoler. Studien visar att akviferen består av sammanhängande jordlager med hög hydraulisk konduktivitet. Beroende på tolkningar och justeringar i modelleringsprocessen visar de två olika modellerna på skillnader vad gäller jordlagrens utbredning och mäktighet. Detta medför skillnader i effektiv hydraulisk konduktivitet mellan modellerna, vilket resulterar i relativt stora skillnader vad gäller transporttider mellan brunnspolerna. Tredimensionella geologiska modeller bedöms bidra till förbättrade hydrogeologiska utredningar då det är ett enkelt och effektivt sätt att bygga upp ett områdes geologi för översikt, tolkning och vidare studier i form av exempelvis grundvattenmodellering.

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14

Said, Md Azlin b. Md. "Water resources modelling using remotely sensed data." Thesis, Cardiff University, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340765.

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15

Jarmander, Anna. "Modellering av grundvattendynamiken och transport av löst organisk kol i Uppsalaåsen." Thesis, Uppsala universitet, Luft-, vatten- och landskapslära, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447876.

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Uppsala esker is the main source of drinking water in Uppsala city and it provides the city with clean water all year around. The demand of drinking water is growing, and the municipality plans on increasing the artificial infiltration in order to meet future demands. During the last years, the concentration of organic carbon in Uppsala’s drinking water has increased which has raised concerns regarding the future drinking water quality. A decrease in the residence time as a result of increased infiltration may partly cause these increasing concentration levels. The aim of this master’s thesis was therefore to recreate the groundwater dynamics in the Uppsala esker with a model and hence, an improved understanding of the transport of organic carbon in order to predict the consequences of an increased artificial infiltration. The thesis also aimed to investigate the potential risk of the concentration of organic carbon in the drinking water to exceed the reference value from the Swedish food agency. The computer code used in this project was MODFLOW together with GMS which together helped creating a simplified, three-dimensional groundwater model of a delimited part of the Uppsala esker that covers Tunåsen infiltration facility down to the well area in Galgbacken. A conceptual model was constructed in GMS for the model domain and was then converted into a numerical MODFLOW steady-state model. The model was then calibrated after both measured groundwater levels with a 40 cm deviation and after the already known residence time for the distance Tunåsen – Galgbacken. Four scenarios with varying infiltration and outtake were then simulated. Each scenario was then simulated with three different incoming concentrations of organic carbon in the infiltration: 7, 15 and 50 mg/L. Results show that the groundwater dynamics can be reconstructed with a simplified model however, it is likely that the simplifications resulted in a less precise model. The transport simulations indicated that the residence time decreases with increased artificial infiltration and outtake. Transport simulations furthermore showed that residence time is the most crucial factor effecting the transport distance of the organic carbon. Lastly, the result indicated that there is a risk that the reference value for organic carbon will be exceeded for incoming concentrations of 15 and 30 mg/L respectively, mainly in scenario C where the maximum infiltration and outtake capacities were simulated. In addition, it was concluded that there may be a risk that the reference value will even be exceeded in the other scenarios with an increased simulation time.
I Uppsala är Uppsalaåsen central för vattenförsörjningen då den förser staden med rent dricksvatten året om. De senaste åren har det observerats en oroväckande ökande trend av halten löst organisk kol (DOC) i grundvattnet. Med ett ökande dricksvattenbehov finns det även planer på att öka den konstgjorda grundvattenbildningen vilket riskerat att öka halterna ännu mer. Examensarbetets syfte var att återskapa grundvattendynamiken med en modell och öka förståelsen för transport av organisk kol i Uppsalaåsen och därefter prediktera möjliga konsekvenser av ökad infiltration. Projektet ämnade dessutom att undersöka om det i framtiden finns en risk att gränsvärdet för organiskt kol i Uppsalas dricksvatten överskrids. I projektet användes modellkoden MODFLOW tillsammans med GMS för att skapa en förenklad, tredimensionell grundvattenmodell. Modelldomänet var en avgränsad del av Uppsalaåsen från Tunåsens infiltrationsanläggning till Galgbackens uttagsområde. Inledningsvis upprättades en konceptuell modell i GMS som sedan konverterades till en numerisk steady-state modell. Modellen kalibrerades efter uppmätta grundvattennivåer och efter tidigare känd transporttid för sträckan Tunåsen – Galbacken. Därefter utfördes simuleringar för fyra scenarion, 0, A, B och C, med varierande infiltration och uttag. För varje scenario utfördes sedan simuleringar med tre olika koncentrationer av halten löst organiskt material i infiltrationsvattnet; 7, 15 och 30 mg/L. I modellen togs det ej hänsyn till någon nedbrytning av DOC, tillskillnad från den nedbrytning på 50 % som har observerats i åsen. Resultatet visade att det är möjligt att återskapa den grundvattendynamik som observerats inom modelldomänet med en förenklad modell. För de olika scenariona visade resultaten att transporttiden minskar med ökad infiltration och ett ökat uttag. I förhållande till scenario 0 visade resultaten på en procentuell minskning av transporttiden på 24, 28 och 60 % för respektive scenario A, B och C. Den kortaste transporttiden erhölls således i scenario C på 183 dagar, jämfört med 293 dagar i scenario 0. Resultaten som erhölls visade även att transporttiden är den dominerande faktorn som påverkar det organiska materialets transportsträcka. Slutligen visade resultatet att det finns en risk att halten av organiskt material överstiger Livsmedelverkets gränsvärde för dricksvatten om koncentrationen av DOC i infiltrationsvattnet är hög i kombination med en kort transporttid.

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16

Syed, Mofazzal. "Data driven modelling for environmental water management." Thesis, Cardiff University, 2007. http://orca.cf.ac.uk/54592/.

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Management of water quality is generally based on physically-based equations or hypotheses describing the behaviour of water bodies. In recent years models built on the basis of the availability of larger amounts of collected data are gaining popularity. This modelling approach can be called data driven modelling. Observational data represent specific knowledge, whereas a hypothesis represents a generalization of this knowledge that implies and characterizes all such observational data. Traditionally deterministic numerical models have been used for predicting flow and water quality processes in inland and coastal basins. These models generally take a long time to run and cannot be used as on-line decision support tools, thereby enabling imminent threats to public health risk and flooding etc. to be predicted. In contrast, Data driven models are data intensive and there are some limitations in this approach. The extrapolation capability of data driven methods are a matter of conjecture. Furthermore, the extensive data required for building a data driven model can be time and resource consuming or for the case predicting the impact of a future development then the data is unlikely to exist. The main objective of the study was to develop an integrated approach for rapid prediction of bathing water quality in estuarine and coastal waters. Faecal Coliforms (FC) were used as a water quality indicator and two of the most popular data mining techniques, namely, Genetic Programming (GP) and Artificial Neural Networks (ANNs) were used to predict the FC levels in a pilot basin. In order to provide enough data for training and testing the neural networks, a calibrated hydrodynamic and water quality model was used to generate input data for the neural networks. A novel non-linear data analysis technique, called the Gamma Test, was used to determine the data noise level and the number of data points required for developing smooth neural network models. Details are given of the data driven models, numerical models and the Gamma Test. Details are also given of a series experiments being undertaken to test data driven model performance for a different number of input parameters and time lags. The response time of the receiving water quality to the input boundary conditions obtained from the hydrodynamic model has been shown to be a useful knowledge for developing accurate and efficient neural networks. It is known that a natural phenomenon like bacterial decay is affected by a whole host of parameters which can not be captured accurately using solely the deterministic models. Therefore, the data-driven approach has been investigated using field survey data collected in Cardiff Bay to investigate the relationship between bacterial decay and other parameters. Both of the GP and ANN models gave similar, if not better, predictions of the field data in comparison with the deterministic model, with the added benefit of almost instant prediction of the bacterial levels for this recreational water body. The models have also been investigated using idealised and controlled laboratory data for the velocity distributions along compound channel reaches with idealised rods have located on the floodplain to replicate large vegetation (such as mangrove trees).

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17

Harrison, Kenneth Watson. "Environmental and Water Resources Decision-Making Under Uncertainty." NCSU, 2002. http://www.lib.ncsu.edu/theses/available/etd-06042002-150804/.

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"Decision-making under uncertainty" is an important area of study in numerous disciplines. The variety of quantitative methods that have been proposed to address environmental and water resources problems reflects the importance of this subject. In a review of the literature, methods were compared and contrasted and promising areas for future research were identified. Conclusions drawn from the review were that 1) large gains may be realized from cross-disciplinary research, 2) significant benefits may be realized from considering uncertainty, 3) advanced algorithms?probabilistic search methods and efficient methods for Bayesian analysis?and increased computing power should greatly extend the applicability of existing methods, and 4) in particular, decision-theoretic methods that have wide application for sequential decision-making. A new decision-theoretic method, Bayesian programming (BP), was developed that takes advantage of the increased computing power and improvements in Bayesian analysis methods. The method has wide applicability, suitable for problems in which there is 1) uncertainty in the modeling, 2) stochastic behavior in the systems that are modeled, 3) the possibility to reduce uncertainty through data collection, and 4) the opportunity for a recourse decision after a period of data collection. The approach combines systematic search methods (mathematical programming) and Bayesian statistical analysis techniques (Markov chain Monte Carlo) in a decision analysis framework. The BP method is tested with application to a hypothetical, but realistic river basin management problem, using real data from the much-studied Athabasca River in Alberta, Canada. The management problem involves balancing the objectives of pulp mill development and water quality protection (dissolved oxygen). Results from application of the BP method were compared with those applying other methodologies. Examination of the results indicated that the BP method is a practical method worthy of additional research. Ultimately, it is hoped, this research will lead to computer-based tools that will improve environmental and water resources decision-making.

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18

Sigfridson, Marcus. "Skyddsinfiltrationens influensområde för en fallstudie : - modellering och osäkerheter." Thesis, Uppsala universitet, Luft-, vatten och landskapslära, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-390702.

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För att uppskatta influensområdet till följd av skyddsinfiltartion finns ett antal analytiska modeller att tillämpa. Dessa modeller tar hänsyn till parametrar så som hydraulisk konduktivitet och magasinkoefficient, men de följer också med en rad antaganden som i praktiken inte kan uppfyllas. En alternativ tillvägagång för att bestämma influensområdet är därför med hjälp av numeriska modeller, som i större grad kan göras platsspecifika. Numeriska modeller är till följd av detta mer tidskrävande och behöver mer indata. I denna studie undersöktes vilken metod som är bäst lämpad för att bestämma skyddsinfiltrationens influensområden för en fallstudie i Bromstens industriområde, belägen cirka 15 km nordväst om Stockholm centrum. Två numeriska modeller med varierande underlag av platsspecifika data utvecklades över områdets geologi och grundvattenmagasin för att kunna simulera grundvattennivåer med och utan infiltration. Utöver detta beräknades influensområdet med fyra analytiska modeller. Modellerna testades sedan utifrån olika scenarion, där såväl dataupplösning som den platsspecifika kännedomen över området stegvis ökades. Platsspecifika data tillkom till följd av geotekniska undersökningar och hydrogeologiska tester. Studien ämnar även att besvara vilken data som är av störst vikt för att bestämma influensområdet med de analytiska respektive numeriska modellerna samt vilka skillnader som uppstår mellan analytiskt beräknade influensområden och numeriskt simulerade influensområden. Resultaten visar att de numeriska modellerna i huvudsak är känsligast med avseende på den hydrauliska konduktiviteten, samt att den enklare numeriska modellen är känslig för magasinkoefficienten, något som indikerar att denna modell inte uppnår jämvikt i enlighet med vad som observerats i fält. Utöver detta stod det klart att vattenavgivningstalet inte hade någon nämnvärd inverkan på resultaten. Bland de analytiska modellerna råder den största känsligheten i magasinkoefficienten, följt av konduktiviteten. För Sichardts formel, som inte tar hänsyn till magasinkoefficienten var konduktiviteten den känsligaste parametern. Akvifärens mäktighet, vilken reviderades mellan scenario 2 och 3, hade ingen betydande inverkan på de analytiska modellerna. Vidare visade infiltrationstestet på stora skillnader i skyddsinfiltrationens influensområde med avseende på de olika modellerna och dataunderlaget. Den minsta avvikelsen mätt i residualer observerades för den komplexa numeriska modellen under scenario 4, vilket motsvarar det scenario då dataunderlaget var som störst. Trots att detta scenario tillsammans med modell anses vara det dyraste fallet, anses detta vara det bästa och samtidigt mest tillförlitligt metoden för att uppskatta skyddsinfiltrationens influensområde.
To evaluate the area of influence due to artificial infiltration several analytical models are available. Some of the parameters taken into account by these models are the hydraulic conductivity and storage coefficient, but with these models some assumptions, which in reality cannot be fulfilled, are made. An alternative approach to evaluate the area of influence is therefore with numerical models, which in a greater extent account for the site-specific conditions. Due to this, numerical models are more time consuming and require more input data. This project aims to investigate the most effective approaches to evaluate the area of influence due to artificial infiltration for a case study in Bromsten, located 15 kilometers northwest of Stockholm. Two numerical models, with different background data due to the extent of site knowledge, were developed to represent the site's geological settings and groundwater properties to simulate the groundwaterlevels with and without infiltration. Moreover the area of influence were calculated with four analytical models. All of the models were then applied on four different scenarios, in which the data resolution and the site knowledge increased. Site-specific data was added as a result of geological surveys and hydrogeological tests. The study also aims to answer which data is most important in order to determine the area of influence with analytical and numerical models and what differences there are between the analytical solutions compared with the numerical solutions. Among the methods investigated, constructing a more complex model with data from scenario 4, the scenario with the greatest data supply, resulted in the most reliable results and was therefore the best method and the method to choose for this case-study. Other results indicated that the numerical models first of all are sensitive to the conductivity and that the more simpel numerical model is sensitive to the storage coefficient as well. The last result shows that this model does not reach the steady state conditions as observed in field, which highlights the importance of goetechnical investigation for the numerical models. Moreover none of the numerical models were sensitive to the specific yield. Among the analytical models the storage coefficient was the most important followed by the conductivity. For one of the analytical models (Sichardts formula) the conductivity was the most sensitive parameter. The thickness of the aquifer had no significant impact on the analytical models.

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19

Shahjahan, Mosharefa. "Integrated management of water resources in Bangladesh /." Title page, table of contents and abstract only, 1999. http://web4.library.adelaide.edu.au/theses/09ENV/09envs525.pdf.

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20

Ricci, Edward D. "Environmental Hazard Evaluations." Arizona-Nevada Academy of Science, 1987. http://hdl.handle.net/10150/296376.

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From the Proceedings of the 1987 Meetings of the Arizona Section - American Water Resources Association, Hydrology Section - Arizona-Nevada Academy of Science and the Arizona Hydrological Society - April 18, 1987, Northern Arizona University, Flagstaff, Arizona

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21

Baresel, Christian. "Environmental management of water systems under uncertainty." Doctoral thesis, Stockholm : Mark- och vattenteknik, Kungliga Tekniska högskolan, 2007. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4396.

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22

Pourfathali, Kasmaei Leila. "Long Term Environmental Modelling of Soil-Water-Plant Exposed to Saline Water." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-99344.

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The impact of long term management strategies of irrigation with saline water in semi-arid region of Gordonia, South Africa is the highest interest to optimize water consumption, soil conservation, and crop yield for sustainable water allocations to human food production and ecosystem without irreversible damages to soil and water body. An integrated ecosystem assimilation, in shape of soil-water storage model based on physical approach for 30-year simulation run defined in form of digital ecosystem modelling with help of CoupModel tool to assemble together the most important underlying processes of soil hydraulics, irrigation demands, leaching fraction, evapotranspiration, salt transport. Two scenarios of water management strategy; surface as traditional and drip as subsurface irrigation considered to apply water and salt into the ecosystem model. Gaining high food production for human with respect to ecosystem sustainability, in each water management scenario studied by evaluating general and detailed result from water and salt balance for the entire simulation period plus long term nitrogen and carbon turnover as crop yield indicator. Non-productive water losses, salt accumulation in root zone, carbon and nitrogen turnover, salt transport to aquifer via deep percolation observed thoroughly. Decline in crop yield due to water and salt stress, conducted by monitoring biomass production with respect to water consumption and soil osmotic pressure in root zone. Drip scenario had better functionality to perform less water wastage by decreasing soil evaporation as non-productive water loss almost 40 %, however productive water consumption decreased 20 % due to insufficient leaching fraction and also salt accumulation increased in root zone. Precipitation had a significant role to accomplish leaching deficiency and removing salt from root zone. Salt accumulation flushed out from root zone by more leaching, though resulting more water wastage and more possibility of salinization threatening beneath aquifer. Ecosystem in terms of soil-water and plant responding differently facing salinity in different water management practices and salt as source of pollution could either stabilized in soil by accumulating in root zone causing anthropogenic soil desertification or percolate to beneath aquifer resulting aquifer salinization.

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23

Yarde, Richard Roy 1969. "State capacity for water resources planning." Thesis, The University of Arizona, 1997. http://hdl.handle.net/10150/291640.

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Since the end of federal funds from the Water Resources Planning Act of 1964, it has been largely the responsibility of the states to plan for their water resources. This study will report on the current status of state water planning, suggest some variables that may have an influence on a state's decision to prepare a state water plan, and test the variables through statistical analysis. Some of the variables that are suggested as having some influence on state water planning are precipitation, population density, large metropolitan areas, median per capita income (as a measure of state affluence), and percent of land irrigated. Among these, it is only precipitation that has a clearly significant correlation to the preparation of a state water plan. It is concluded that no single variable is an accurate predictor of state behavior, but that a combination of variables act together to influence state behavior.

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24

Robinson, Allan. "Integrated systems modelling of the interaction between water resources and agriculture." Thesis, Cranfield University, 1999. http://hdl.handle.net/1826/3903.

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Environmental problems associated with the use of water are inherently complex, involving the interaction of several different systems. Further, there is often limited data on the interaction, because of its location between disciplines. In order to study these problems in a quantitative, policy relevant way, a numerical model is required that integrates the different systems and is tailored to contain the processes important to the interaction. A numerical water resource system model is developed to study the problems associated with the interaction between agriculture and water. The model integrates an econometric model of farmer behaviour with a dynamic model of water flow and solute transport. The Argolid valley in Greece represents an area where severe environmental problems have arisen as a result of the overexploitation of groundwater for agriculture. When applied to the Argolid valley the water resource system model reproduces the evolution of the environmental problems that have arisen. It is then demonstrated that the model can be used to investigate some future scenarios and policy options related to the environmental problems that have developed. The main contribution of this research is to demonstrate that a properly designed numerical model that reproduces the dynamic interaction between human behaviour and the physical environment can enable the exploration of the evolution of environmental problems despite a lack of calibration data. Having achieved this the model can then be used in a policy relevant way to investigate the implications from a range of different, possible policy options.

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25

Counsell, Christian John Adam. "End-to-end ensemble modelling for water resources planning under uncertainty." Thesis, Open University, 2018. http://oro.open.ac.uk/56567/.

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A hydrological model ensemble, considering two model structures (CatchMOD and PDM), parameter uncertainty and two contrasting methods for estimating potential evapotranspiration (PET), is developed to investigate the relative significance of different sources of uncertainty for water resources planning in the Thames basin. This model ensemble is driven by an ensemble of UKCP09 probabilistic and Future Flows climate change projections, for the 2030s, 2050s and 2080s, to quantify the projected impacts on a range of metrics of relevance to water resources planners using a water resources system model of London. These sources of supply-side uncertainty are shown to be significant, with the uncertainty associated with the climate change scenarios the largest but hydrological modelling uncertainty, and the method used to estimate PET also shown to be considerable. In terms of overall impacts, the central estimates for the 2030s, 2050s and 2080s are reductions in available resource of around 7%, 11% and 14% respectively. These impacts are shown to equate to economic costs of the order of £360m, £610m and £735m respectively to mitigate such reductions in supply. The range of uncertainty within each time-horizon is large, greater than the differences between the time-horizons, presenting a significant challenge in deciding the level and timing of investments to mitigate emerging risks. As an example, impacts considered reasonably likely by the 2080s (e.g. a central estimate of 14% impact on deployable output using both PET methods) may be as likely by the 2030s (e. g. using only the modified Penman-Monteith PET method). The estimates of future supply reliability are contrasted with demand forecasts and whilst the pressure associated with the latter is shown to be greater, both are significant and subject to large degrees of uncertainty. This thesis also highlights the need for detailed examination of hydrological model structures to provide evidence as to their strengths and weaknesses in their representation of key processes, particularly during droughts. The limitations of the climate change products currently used in the industry, particularly with regards to droughts and estimating changes in PET, are also explored. Significant ongoing research is developing decision-making approaches to support the planning of robust and resilient systems under an uncertain future. This thesis demonstrates that alongside this development, more research is needed to understand, identify and quantify the significant sources of uncertainty that need to be considered as part of the decision-making process.

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26

Abbas, Salam A. A. "Hydrological modelling for integrated water resources management in a changing climate." Thesis, Swansea University, 2018. https://cronfa.swan.ac.uk/Record/cronfa43733.

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Hydrological models are a simplified representation of hydrological processes and can be very used for the water resources assessment and gain an integral view of the water resources status for integrated water resources management IWRM. Furthermore, they can be used to investigate the possible impacts and trends resulting from different types of scenarios, such as climate change impact studies. Accordingly, with IWRM as the future application, the primary objectives of this study is to use a hydrological model, SWAT for the modelling of a highly-regulated river basin through the physical flow control (reservoirs release in the upstream region), the Dee River Watershed in the United Kingdom. Moreover, an essential aspect of model input uncertainty, i.e. precipitation is investigated on the simulated streamflow where different methods of rainfall pre-processing are used. Furthermore, a quantile regression method is employed for analysing the long-term historical trend of rainfall, river flow and catchment water yields focusing on the patterns of the data close to 'extreme' regimes, to link them to the events of interests for the climate change impact studies. Additionally, a reliable simulation of both land surface and groundwater hydrological processes is a far important step for IWRM. One way to achieve such purpose is the coupling of surface and groundwater models. The land surface model (SWAT) is coupled with the groundwater flow model (MODFLOW) to improve the baseflow simulation of the SWAT standalone in the study area. Another critical aspect of this study is the investigation of parameter uncertainty of the coupled SWAT-MODFLOW. Finally, the climate projection data from the CMIP5 project is utilised with allocation model, Water Evaluation and Planning software WEAP to address climate change impact for future scenarios on water resources. All presented models performed well in demonstrating the study conditions, as indicated by the statistical performance. The research approach of the integrated models can generally apply to any catchment and inspired by the need of considering all aspects related to hydrological models for IWRM to bridge the gap of between stakeholder involvement and natural hydrological processes in building and applying integrated models to ensure acceptability and application in decision-making for IWRM.

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27

Manning, Jill Anna. "Water resources of west Cape Cod : an investigation of water supply and demand planning." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/43357.

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28

Buscemi, Pablo E. (Pablo Edgardo) 1964. "Integrating water resources management : analysis of the St. Thomas, U.S. Virgin Islands, water market." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29324.

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Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2003.
Includes bibliographical references (p. 103-105).
The purpose of this thesis is to contribute to the understanding of the water resources management of the St. Thomas water market. By applying the framework for Integrated Water Resources Management, the actual water resources situation in the island was analyzed. This framework requires meeting three criteria: economic efficiency in water use, environmental and ecological sustainability, and equity in the access to water for all the population. The study includes the assessment of available water supply and water demand by use, and the evaluation of alternative and feasible supply options to augment freshwater resources. Three potential main supply strategies for freshwater supply were identified and compared based on: 1) economic efficiency in water use, 2) environmental and ecological sustainability, and 3) equity in the access to water for all people. Four integrated strategies for future development and management of water resources in the island were recommended: 1) Gradually phasing out desalination based on distillation as the main strategy of water supply. This supply can be replaced with distributed reverse osmosis desalination and by importing water by submarine pipeline from Puerto Rico. 2) Gradually expanding the distribution system to the entire population, applying the funds saved by shifting to more cost-effective and sustainable freshwater supply alternatives. 3) Developing water trading policies within the island as well as with neighboring islands. 4) Improving accountability for available water supplies, which is a basic need for water managers and planners informed decision making.
by Pablo E. Buscemi.
M.Eng.

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29

Sahu, Reetik Kumar. "Multi-agent real-time decision making in water resources systems." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/120636.

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Thesis: Ph. D. in Computational Science and Engineering, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2018.
Cataloged from PDF version of thesis.
Includes bibliographical references (pages 77-83).
Optimal utilization of natural resources such as water, wind and land over extended periods of time requires a carefully designed framework coupling decision making and a mathematical abstraction of the physical system. On one hand, the choice of the decision-strategy can set limits/bounds on the maximum benefit that can be extracted from the physical system. On the other hand the mathematical formulation of the physical system determines the limitations of such strategies when applied to real physical systems. The nuances of decision making and abstraction of the physical system are illustrated with two classical water resource problems: optimal hydropower reservoir operation and competition for a common pool groundwater source. Reservoir operation is modeled as a single agent stochastic optimal control problem where the operator (agent) negotiates a firm power contract before operations begin and adjusts the reservoir release during operations. A probabilistic analysis shows that predictive decision strategies such as stochastic dynamic programming and model predictive control give better performance than standard deterministic operating rules. Groundwater competition is modeled as a multi-agent dynamic game where each farmer (agent) aims to maximize his/her personal benefit. The game analysis shows that uncooperative competition for the resource reduces economic efficiency somewhat with respect to the cooperative socially optimum behavior. However, the efficiency reduction is relatively small compared to what might be expected from incorrect assumptions about uncertain factors such as future energy and crop prices. Spatially lumped and distributed models of the groundwater system give similar pictures of the inefficiencies that result from uncooperative behavior. The spatially distributed model also reveals the important roles of the geometry and density of the pumping well network. Overall, the game analysis provides useful insight about the factors that make cooperative groundwater management beneficial in particular situations.
by Reetik Kumar Sahu.
Ph. D. in Computational Science and Engineering

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30

Al-Mohannadi, Hassan I. "Water resources in the State of Qatar : toward holistic management." Thesis, University of Huddersfield, 2001. http://eprints.hud.ac.uk/id/eprint/4752/.

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31

Yurdusev, Mehmet Ali. "Integration of environmental concerns into large-scale water-resources planning models." Thesis, University of Newcastle Upon Tyne, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388126.

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32

Herrera, Catalán Pedro, and Oscar Millones. "Estimating the Cost of Mining Pollution on Water Resources: Parametric and Nonparametric Resources." Economía, 2012. http://repositorio.pucp.edu.pe/index/handle/123456789/117289.

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This study estimates the economic costs of mining pollution on water resources for the years 2008 and 2009 based on the conceptual framework of Environmental Efficiency. This framework identifies such costs as the mining companies’ trade-off between increasing production that is saleable at market prices (desirable output) and reducing the environmental pollution that emerges from the production process (undesirable output). These economic costs were calculated from parametric and non parametric production possibility frontiers for 28 and 37 mining units in 2008 and 2009, respectively, which were under the purview of the National Campaign for Environmental Monitoring of Effluent and Water Resources, conducted by the Energy and Mining Investment Supervisory Agency (Osinergmin) in those years. The results show that the economic cost of mining pollution on water resources rose to U.S. $ 814.7 million and U.S. $ 448.8 million for 2008 and 2009, respectively. These economic costs were highly concentrated in a few mining units, within a few pollution parameters, and were also higher in mining units with average/low mineral production. Taking into consideration that at present the fine and penalty system in the mining sector is based on administrative criteria, this study proposes a System of Environmentally Efficient Sanctions based on economic criteria so as to establish a preventive mechanism for pollution. It is hoped that this mechanism will generate the necessary incentives for mining companies to address the negative externalities that emerge from their production process.
En este estudio se aproximan los costos económicos de la contaminación ambiental minera sobre los recursos hídricos para 2008 y 2009 en el marco conceptual de la Eficiencia Medioambiental, que interpreta dichos costos como el trade-off de los empresarios mineros entre incrementar su producción que es vendible a precios de mercado (output deseable) yreducir la contaminación ambiental que se desprende de su proceso productivo (output no deseable). Dichos costos económicos fueron calculados a partir de fronteras de posibilidades de producción paramétricas y no paramétricas para 28 y 37 unidades mineras en los años 2008 y 2009 respectivamente, las que estuvieron bajo el ámbito de la Campaña Nacional deMonitoreo Ambiental de Efluentes y Recursos Hídricos que realizó el Organismo Supervisor de Inversión Energía y Minería (Osinergmin) en dichos años. Los resultados indican que los costos económicos de la contaminación ambiental minera sobre los recursos hídricos ascendieron, en promedio, para los años 2008 y 2009, a US$ 814,7 millones,y US$ 448,8 millones, respectivamente. Dichos costos estuvieron altamente concentrados en pocas unidades productivas, así como en pocos parámetros de contaminación, y fueron mayores en unidades mineras con producción media/baja de minerales. Dado que en la actualidad el sistema de multas y sanciones en el sector minero se basa en criterios administrativos, el estudio propone un Sistema de Sanciones Ambientalmente Eficiente basado en criterios económicos

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33

Stubbs, Christopher M. (Christopher Michael). "Integrated water resources management in the Chao Phraya River basin, Thailand." Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/40593.

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34

Survis, Felicia D. "Beyond Water Restrictions| Informing Effective Lawn Watering Behavior." Thesis, Florida Atlantic University, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10300326.

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Evaluating trends of historical rainfall on a weekly and seasonal basis is needed for optimizing the design and implementation of lawn water conservation strategies like outdoor water restrictions. While “day of the week” water restrictions are a typical strategy to limit the frequency and duration of urban lawn water use, they may not necessarily result in more conservative behaviors from end-users. Because weekly rainfall and local climate variables are seldom taken into account in water restriction strategies, they are not connected to actual lawn water demand. However, since lawn water demand is directly related to weekly rainfall totals, not to a particular number of watering days per week, water restriction schedules have the potential to unintentionally promote overwatering. This study investigated the weekly patterns of average seasonal rainfall and evapotranspiration in South Florida to determine the typical variability of weekly net irrigation needs and found that typical wet season weekly rainfall often provides a significant amount of water to meet the demand of residential lawns and landscapes. This finding underscores opportunity to reduce supplemental overwatering in residential landscapes if watering guidelines were modified to recognize seasonal average weekly rainfall in this region.

This study also tested a rainfall-based water conservation strategy to determine if providing residents with information about how local rainfall could promote more effective lawn watering behavior than just water restrictions alone. Experimental households reduced lawn water use by up to 61% compared to the control group by the end of the study. These results demonstrate that the neighborhood “rain-watered lawn” signs helped experimental study group households become more aware of rainfall as the primary input of water to their lawns. This study also investigated the role that lawn irrigation from self-supplied sources plays in the urban lawn water demand and investigates how the lawn water use and lawn watering behaviors of households that source from self-supply differ from those who source from the public supply.

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35

Nechifor-Vostinaru, V. "Modelling freshwater resources use and the economic impacts of demand-driven water scarcity." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10049597/.

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Water deficits are increasingly perceived as a threat to future global prosperity. Given current projections of population growth and economic development, the pressure over the water resource base coming from human abstraction would continue to expand including in regions currently dealing with water scarcity. The aim of this thesis is to determine the implications of demand-driven water deficits for economic development and food security by accounting for three major factors influencing future water demand – income, population and climate change. The first main contribution of this thesis consists in the advance of the current state-of-the-art in the macroeconomic modelling of freshwater use and the endogenous mechanisms of adaptation to water scarcity. The second contribution is the development of knowledge regarding the sector-specific impacts of water scarcity under different water allocation regimes. The analyses are carried out through a global Computable General Equilibrium model (RESCU-Water) which considers the heterogeneity of water uses across the economy. Due to the importance of irrigation in global withdrawals, an emphasis is made on crop systems through a bottom-up representation of irrigated and rainfed crop production. The findings show that the aggregate economic effects of water scarcity highly depend on the choice of the water allocation method, with important trade-offs between food security and GDP impacts. Next, although the demand for irrigation water is slowing down in the next decades, any water allocation regime based on differences in sectoral water productivities will have a significant impact on crop production notably on staple crops. In this context, the demand-driven water deficits become an additional constraint for crop systems and further amplify the negative effects of climate change on crop output.

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36

Mekonnen, Kefyalew. "The economics of developing water resource projects in the Ethiopian Nile River basin : their environmental, and transboundary implications /." The economics of developing water resource projects in the Ethiopian Nile River basinRead the abstract of the thesis, 2003. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe17380.pdf.

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37

Khan, Adil A. "Race for water resources among Beaufort / Jasper, SC and Effingham / Chatham, GA counties." Thesis, Savannah State University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=1537007.

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The municipal and public officials in Beaufort/Jasper, South Carolina (SC) and Effingham/Chatham, Georgia (GA) counties in the lower Savannah River Basin (LSRB) are faced with a dilemma of supplying potable water on an equitable basis to their communities from the surface and groundwater that has been partially polluted and/or is not sustainable. State regulatory agencies have implemented strategies to protect the regional water resources from further degradation of ecosystems, but these remedies are not addressing a crucial issue. The potable water issue is more critical than simply affecting to protect the local ecosystem. Hence, the thesis question is:

Can current strategies, by the South Carolina Department of Health and Environmental Control (SCDHEC) and the Georgia Environmental Division (GAEPD), secure potable water sources from the lower Savannah River Basin in the region, potentially provide effective, efficient, and equitable results?

Economic development and demographic changes have equally impacted the surface and groundwater. Groundwater was the primary source of potable water in predevelopment (prior to industrial revolution) and even post development era, but gradually became unsustainable. The alternative surface water source has also been polluted by the industrial and domestic wastewater treatment plant discharges. Surface water contains natural organic compounds, and even that has been overwhelmed by the added pollutants in wastewater treatment plant effluent. This has further increased formation of potential carcinogenic disinfection and disinfection byproducts in potable water. The carcinogen removal process has become expensive, but the potential risk for contamination remains problematic.

To answer the research question, interviews and surveys were conducted. The population for this research consists of municipal and public officials and water treatment professionals. The samples were selected due to their expertise and responsibility to supply safe drinking water to their communities. Collected data analyzed using Microsfot Excel to arrange in matrixes, and explained in simple narratives. The results were summarized and recommendations were made.

Most of the subjects agreed that water resources are not sustainable at current usage rate in the region. Groundwater is not sustainable and surface water quality has deteriorated due to organic pollutants in the industrial and domestic wastewater treatment plant (WWTP) effluents. The cost of producing safe drinking water from partially or potentially polluted surface water is higher than the cost of processing groundwater. The cost of desalination of seawater or brackish well water is even higher than ground or surface water treatment.

Seawater desalination is not a cost effective option now. However, conflicting interests regarding the switch over to seawater desalination as long as surface water treatment operating cost remains lower than the seawater desalination, surface water will remain a sustainable source.

Although seawater desalination is a more sustainable strategy to produce potable water in the Low Country Region. Surface water treatment is less expensive and in turn, local professionals view it as the best option. This I believe is a limited short term viewpoint, which does not address longterm sustainability issues. Efforts regulatory agencies and utilities, to produce safe drinking water from surface water will continue in the Lower Savannah River Basin (LSRB).

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38

Wang, Lizhong. "Cooperative Water Resources Allocation among Competing Users." Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/867.

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A comprehensive model named the Cooperative Water Allocation Model (CWAM) is developed for modeling equitable and efficient water allocation among competing users at the basin scale, based on a multiperiod node-link river basin network. The model integrates water rights allocation, efficient water allocation and equitable income distribution subject to hydrologic constraints comprising both water quantity and quality considerations. CWAM allocates water resources in two steps: initial water rights are firstly allocated to water uses based on legal rights systems or agreements, and then water is reallocated to achieve efficient use of water through water transfers. The associated net benefits of stakeholders participating in a coalition are allocated by using cooperative game theoretical approaches.

The first phase of the CWAM methodology includes three methods for deriving initial water rights allocation among competing water uses, namely the priority-based multiperiod maximal network flow (PMMNF) programming, modified riparian water rights allocation (MRWRA) and lexicographic minimax water shortage ratios (LMWSR) methods. PMMNF is a very flexible approach and is applicable under prior, riparian and public water rights systems with priorities determined by different criteria. MRWRA is essentially a special form of PMMNF adapted for allocation under the riparian regime. LMWSR is designed for application under a public water rights system, which adopts the lexicographic minimax fairness concept. The second step comprises three sub-models: the irrigation water planning model (IWPM) is a model for deriving benefit functions of irrigation water; the hydrologic-economic river basin model (HERBM) is the core component of the coalition analysis, which searches for the values of various coalitions of stakeholders and corresponding optimal water allocation schemes, based on initial water rights, monthly net benefit functions of demand sites and the ownership of water uses; the sub-model cooperative reallocation game (CRG) of the net benefit of the grand coalition adopts cooperative game solution concepts, including the nucleolus, weak nucleolus, proportional nucleolus, normalized nucleolus and Shapley value, to perform equitable reallocation of the net benefits of stakeholders participating in the grand coalition. The economically efficient use of water under the grand coalition is achieved through water transfers based on initial water rights.

Sequential and iterative solution algorithms utilizing the primal simplex method are developed to solve the linear PMMNF and LMWSR problems, respectively, which only include linear water quantity constraints. Algorithms for nonlinear PMMNF and LMWSR problems adopt a two-stage approach, which allow nonlinear reservoir area- and elevation-storage relations, and may include nonlinear water quality constraints. In the first stage, the corresponding linear problems, excluding nonlinear constraints, are solved by a sequential or iterative algorithm. The global optimal solution obtained by the linear programming is then combined together with estimated initial values of pollutant concentrations to be used as the starting point for the sequential or iterative nonlinear programs of the nonlinear PMMNF or LMWSR problem. As HERBM adopts constant price-elasticity water demand functions to derive the net benefit functions of municipal and industrial demand sites and hydropower stations, and quadratic gross benefit functions to find the net benefit functions of agriculture water uses, stream flow demands and reservoir storages, it is a large scale nonlinear optimization problem even when the water quality constraints are not included. An efficient algorithm is built for coalition analysis, utilizing a combination of the multistart global optimization technique and gradient-based nonlinear programming method to solve a HERBM for each possible coalition.

Throughout the study, both the feasibility and the effectiveness of incorporating equity concepts into conventional economic optimal water resources management modeling are addressed. The applications of CWAM to the Amu Darya River Basin in Central Asia and the South Saskatchewan River Basin in western Canada demonstrate the applicability of the model. It is argued that CWAM can be utilized as a tool for promoting the understanding and cooperation of water users to achieve maximum welfare in a river basin and minimize the damage caused by water shortages, through water rights allocation, and water and net benefit transfers among water users under the regulated water market or administrative allocation mechanism.

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39

Scott, Robin M. "Development of environmental water monitors based on hydrostatic and flourescence detection techniques." Thesis, University of Hull, 2009. http://hydra.hull.ac.uk/resources/hull:2491.

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The research for this thesis led to the development of two environmental detectors, whose function was to identify predetermined threshold levels of the analyte. The research centred onto two types of analyte; immiscible and dissolved, both occurring in water based locations. The first detector was developed to detect the accumulation of oil within an oil/water interceptor. Pollution from oil spillages is a major contaminate of water systems and the control of this potentially hazardous material has legal obligations. This liquid, which naturally separates from water, accumulates within the interceptor enclosure and can be removed once the quantity of oil reaches the desired level. However, the often unpredictable nature of oil leaks and spillages means that the accumulation of oil within an interceptor is an irregular occurrence. Interceptor detectors based upon electrical techniques already exist. This research specifically developed a detection system that operated without any electrical devices within the interceptor. The research explored several possible avenues, eventually pursuing a technique based upon pressure change, based on the density differential between water and oil. The final system was capable of identifying when the oil had reached a depth of 200 to 250 mm within the interceptor. The second detection system, a portable microfluidic fluorimeter, was intended for placement in locations for the direct analysis of water. Glutathione was chosen as a model analyte, associated with a sex pheromone and prior to the onset of spawning may be found in high concentrations. The system that has been developed is capable of selectively sensing glutathione to below 10 μM. However, the threshold concentration in the proximity of its release as a pheromone is greater than 100 μM and within this range the fluorimeter produced a linear response. The fluorimeter used an LED light source with a PMT detector. An analysis could be made every seven minutes, using 150 μL each of analyte and reagent for every cycle. Through assessment of a pre-made standard, the viability of the microfluidic system could be assured with regards to blockages or other malfunctions of the system.

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40

Olagunju, Kehinde. "Drinking Water Quality Perception Survey in the SIUE Community." Thesis, Southern Illinois University at Edwardsville, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10685668.

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Water quality perception is borne out of various factors, which include taste, risk perception, water chemical and microbial parameters, trust in supplier, among others. This study addressed some of the factors that influence drinking water quality perception in the SIUE community for tap and bottled water. This was done through a survey that was delivered to the students, faculty, administration, staff, and alumni members of the university; a link to the online survey was provided via the school email, and a total number of 779 respondents participated in the survey. Some of the variables used in this study are based on general concern for taste, cost, water-chemicals (such as lead), drinking water behavior as well as demographic variables such as age, knowledge level and ethnicity. This study is based on data received from the survey conducted of the SIUE population for undergraduates, graduates, faculty, staff, administration, and alumni. Data were analyzed using several statistical methods including Spearman rank correlation coefficient and Kruskal-Wallis test. The results indicated that age and ethnicity have a significant impact on water quality perception. Drinking water behavior, age, and knowledge are well correlated in this study; therefore, they were not able to be separated.

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41

Buahin, Caleb A. "Advancing the Cyberinfrastructure for Integrated Water Resources Modeling." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/6901.

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Like other scientists, hydrologists encode mathematical formulations that simulate various hydrologic processes as computer programs so that problems with water resource management that would otherwise be manually intractable can be solved efficiently. These computer models are typically developed to answer specific questions within a specific study domain. For example, one computer model may be developed to solve for magnitudes of water flow and water levels in an aquifer while another may be developed to solve for magnitudes of water flow through a water distribution network of pipes and reservoirs. Interactions between different processes are often ignored or are approximated using overly simplistic assumptions. The increasing complexity of the water resources challenges society faces, including stresses from variable climate and land use change, means that some of these models need to be stitched together so that these challenges are not evaluated myopically from the perspective of a single research discipline or study domain. The research in this dissertation presents an investigation of the various approaches and technologies that can be used to support model integration. The research delves into some of the computational challenges associated with model integration and suggests approaches for dealing with these challenges. Finally, it advances new software that provides data structures that water resources modelers are more accustomed to and allows them to take advantage of advanced computing resources for efficient simulations.

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42

Mederer, Joachim. "Water Resources and Dynamics of the Troodos Igneous Aquifer-system, Cyprus - Balanced Groundwater Modelling -." Doctoral thesis, kostenfrei, 2009. http://www.opus-bayern.de/uni-wuerzburg/volltexte/2009/3730/.

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43

Assefa, Kibreab. "Groundwater recharge modelling: linkage to aquifers and implications for water resources management and policy." John Wiley & Sons, 2013. http://hdl.handle.net/1993/22212.

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The main goal of this research is to develop and test a groundwater recharge estimation method that can address some of the key research priorities in groundwater. In this context use is made of various modelling tools including ArcGIS, field data (in situ observations of soil temperature and soil moisture), and soil physics as represented by a physically based vadose zone hydrologic model (HYDRUS-1D). The research is conducted in a pilot watershed in north Okanagan, Canada. The public version of HYDUS-1D and another version with detailed freezing and thawing module are first used to investigate seasonal distribution of heat and water movement in the vadose zone. Model performance is evaluated in different scales by using field data, the gradient-based optimization algorithm of HYDRUS-1D, and ROSETTA derived prior information about soil hydraulic parameters. The latter are fitted to statistical distributions and used in Monte-Carlo experiments to assess the potential uncertainty in groundwater recharge due to model parameters. Next, the significance of the recharge estimation method for catchment scale transient groundwater modelling is demonstrated by applying uniform and variable flux boundary condition to a saturated zone transient groundwater model, MIKESHE. The results showed that the traditional uniform recharge assumption can lead to misleading decisions related to water resources management and pumping well network design. The effect of pumping well network and the provincial Water Act on water resources sustainability are further examined in an evolving climate. The results suggest potential water resource problem in the basin, which can possibly be attributed to the previously installed pumping well network (depth and screen level), and the provincial water use policy. The findings of this study demonstrate that such problems related to inappropriate well network and water resource management can greatly be minimised with the use of the recharge estimation method developed in this study.

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Kareem, Hayder. "Study of water resources by using 3D groundwater modelling in Al-Najaf region, Iraq." Thesis, Cardiff University, 2018. http://orca.cf.ac.uk/111826/.

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Groundwater is a vital water resource in many areas in the world, particularly in the Middle-East region where the water resources become scarce and depleting. Sustainable management and planning of the groundwater resources become essential and urgent given the impact of the global climate change. This research will use a new hydraulic conductivity estimation “Distributed Value Property Zones” approach, which is integrated into a state-of-the-art computer model—the Visual MODFLOW (version 4.6)—to assess the current state of groundwater resources and the risk of future water resource security in the region centred at Al-Najaf province, which is located in the mid-west of Iraq and adjacent to the Euphrates River. It will also explore and assess the groundwater aquifer-Euphrates River interaction. The impact of the interface soil layer located between the two soils of Al-Najaf region aquifer is studied, which is considered to be the second novelty in this research. The model is calibrated both statically and dynamically. The new hydraulic conductivity approach is highly improved the calibration process, particularly the dynamic process. Where, the application of the dynamic calibration with a 16.5 mm/year recharge rate shows the best correspondence with the field observations. After considering the new approach, sensitivity analysis and validation process are also carried out to evaluate the behaviour of the model, which reveals acceptable convergence. Ignoring the interface soil layer from the conceptualisation process and considering the aquifer as one layer only has affected the model’s results. Specifically, only 0.24 km2 dry area appears in the aquifer as compared with the current state’s results of the groundwater aquifer when the interface soil layer is modelled. In addition, the Euphrates River leakage results are different due to the impact of the interface soil layer when compared with those results when ignoring it from the modelling process. Calibration is also affected. The calculated heads were high and dispersed when compared with those heads when the interface soil layer is modelled. This affects the accuracy and acceptability of the model’s calibration results. The results of the current state of Al-Najaf region show a general flow pattern from the west to east of the study area, which agrees well with the observations and the gradient of the ground surface. With the current discharges taken from 69 wells in the study area, a dry area is found in the top and bottom layers, which equals 39 km2 and 1.32 km2, respectively. This indicated a degree of insufficiency of water resources in the study area because the groundwater aquifer supplies only 84% of the current water demand from the pumping schedules. The computed groundwater balance shows that the Euphrates River supplies water of 5354 m3/day into the groundwater aquifer, instead of gaining water from the recharge of 23527 m3/day if no water is pumped from the wells. The predicted impact of climate change cases concludes that the largest effect on the groundwater-Euphrates River connection is when reducing the recharge rate and the western constant head. In particular, the groundwater aquifer's dry area will increase dramatically and will reach 150 km2 and 120 km2 in the top and bottom layers, respectively. The Euphrates River will also suffer hugely through the loss of 14100 m3/day due to the reduction of either the recharge rate or the western constant head. Increasing the pumping schedule for future use will also impact on both the groundwater aquifer and the Euphrates River. Reducing the Euphrates River level by 0.5m or 1m will slightly affect the leakage from the river and the study area's dryness. To control the impact on the groundwater aquifer and its connection with the Euphrates River, it is highly recommended to remove some wells from the pumping schedule and reduce the pumping rate of the other wells, and constantly monitoring the behaviour of both over time. It is expected that the results obtained from the study can provide important information for the sustainable and effective planning and management of the groundwater resources for Al-Najaf City and the surrounding area.

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Al-Gunied, Hussien Alawi. "Environmental impact asssessment of wastewater management in the Republic of Yemen." Thesis, University of Salford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244833.

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Pagan, Brianna Rita. "Understanding the Potential Impacts of Climate Change on Water Resources in Southern California." Digital Commons at Loyola Marymount University and Loyola Law School, 2015. https://digitalcommons.lmu.edu/etd/889.

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Southern California is located in a semi-arid climate with finite natural supplies of water. Precipitation in the area generally occurs in the fall and winter months. Consequently, the region relies on imported water originating primarily from snowpack in northern areas of California and surrounding states including 1) the San-Joaquin River and Tulare Lake basins, 2) the Sacramento River basin, 3) Owens Valley and Mono Lake basins and 4) the Colorado River basin. This study provides an integrated approach to understanding and assessing climate change impacts on the hydrologic cycle for all water supplies to Southern California. A 10-member ensemble of coupled global climate models is dynamically downscaled forcing one regional and one hydrological model resulting in a high-resolution 4.17-km output for the region. Greenhouse gas concentrations are prescribed according to the IPCC Representative Concentration Pathway 8.5 using the present-day period of 1966-2005 as a baseline with a future period of 2011-2050. On the annual timescale, increases in precipitation and evaporation are projected throughout the majority of the study area with the exception of the Owens Valley and Mono Lake basins. As a result, only a minor runoff reduction in the California Sierra Nevada and a minor increase in the Colorado River basin are simulated. Although these changes in annual runoff are minimal, the interannual variability of runoff also increases across all basins indicating a higher probability of extreme wet or dry years and fewer average years. Furthermore, increased temperatures result in significant reductions in snow water equivalent along with earlier shifts in snowmelt timing. Precipitation that falls is less likely to fall as snow, decreasing snowpack and natural storage. On one hand, the escalating likelihood of runoff occurring earlier in the year poses a significant flood control risk to the region requiring the release of water from reservoirs to prevent flooding. On the other hand, the increased likelihood of drought necessitates additional multiyear storage solutions for Southern Californian water resources.

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Adams, Lauren. "Optimized Reservoir Management for Downstream Environmental Purposes." Thesis, University of California, Davis, 2019. http://pqdtopen.proquest.com/#viewpdf?dispub=10973511.

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In regulated rivers, reservoir operation decisions largely determine downstream river temperature and flow. Computational methods can minimize the risk and uncertainty of making regrettable environmental release decisions and aid operations planning and performance prediction. Mathematical modeling in particular can optimize the timing and magnitude of reservoir release decisions for downstream benefit while accounting for seasonal uncertainty, water storage impact, and competing water demands. This dissertation uses optimization and modeling techniques, modifying traditional optimization modeling to include temporal correlation in outcome variables and incorporating long-term planning and risk management into prescribed reservoir operations. The proposed method is implemented in one case, a) with a state variable that tracks outcome benefits over time (fish population size) and, in another case, b) with a maximin stochastic dynamic program solution algorithm that maximizes net operational benefit and minimizes worst-case outcomes (for cold water habitat delivery). This method is particularly useful for environmental flow management, when the water quality and quantity of the river and reservoir in one time step affect the quantity and quality in the reservoir and the river for later periods. Better solutions with these methods internalize risk and hedge releases at the beginning of an operating season to maximize downstream benefit and reduce the probability of catastrophe for the season and future years. Maximizing the minimum cold-water habitat area over months of a season or multiple years, or maximizing a river indicator variable explicitly, could likely help, for example, maximize an out-migrating salmon smolt population downstream. The method is demonstrated with a case study optimizing environmental releases from Folsom Dam and another optimizing temperature management from Shasta Dam in northern California. These results inform general rules for environmental flow management and temperature management of reservoirs, with specific policy recommendations for both Folsom and Shasta reservoirs. In both cases, the added value from employing hedging rules help reservoir operations minimize the risk of environmental catastrophe and conserve storage both within an operating season and across years.

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Voskaki, Asimina. "Modelling framework for evaluation environmental strategy and water management efficency at airports." Thesis, Cranfield University, 2011. http://dspace.lib.cranfield.ac.uk/handle/1826/6997.

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The growing concern about climate change and environmental protection represent significant barriers towards growth in the aviation sector. Currently, airport operators need to consider not only noise control and local air, soil and water pollution management, but also to control the consumption of nonrenewable natural resources and to minimise their impact on climate change. A detailed analysis of current applied practices pointed out that the main issues that airports need to manage, have to do principally with control of natural resources consumption, control of noise and management of emissions, water quality, waste and ecosystems. Although these issues in most of cases have been identified, airports’ priorities regarding their management were not easily acknowledged. The key findings of this research suggest that in the case of environmental management strategies, different patterns exist; thus, some airports seem to seek balance mostly between mitigating global and local environmental issues or resource consumption control and pollution management, while others obviously take measures aimed at managing one or the other impact. In the case of water management efficiency, while many airports seem to have applied measures to sustain water quality, only a few of them have applied sufficient consumption control measures.

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Mukheibir, Pierre. "Water, climate change and small towns." Doctoral thesis, University of Cape Town, 2007. http://hdl.handle.net/11427/4785.

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Includes abstract.
Includes bibliographical references (leaves 205-223).
This thesis examines the interrelationship between “water, climate change and small towns”. The research question is framed in three parts: 1) can climate change be integrated into existing planning frameworks? 2) can small towns build resilient strategies against projected climate change impacts? and, 3) is adaptation to climate change an economic issue? It is evident that very little synergy exists between the different sectors dealing with water access. A holistic view of access and the impact of climate change does not exist in the sustainable development, urban planning and water resources management sectors. It is therefore proposed that the successful delivery of accessible water services lies with the integration of the urban planning, water resources management and climate change adaptation responses. In order to achieve this, a planning framework is introduced.

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Dube, Renias Admore. "Appropriate positioning of modelling as a decision support tool for surface water resources planning in South Africa." Thesis, Pretoria : [s.n.], 2006. http://upetd.up.ac.za/thesis/available/etd-08242006-122230.

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Thesis (Ph.D) (Microbiology and Plant Pathology)--University of Pretoria, 2006.
Summaries in Afrikaans and English. Includes bibliographical references. Available on the Internet via the World Wide Web.

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