Water scarcity is a prevalent issue all over the world. Growing water abstractions combined with uncertain effects of climate increase competition for scarce water resources worldwide, especially in arid and semiarid regions. It is crucial to assess and manage available water resources to ensure its sustainability. There is a need for integrated water management at a watershed scale. Watershed models are a useful tool to support sustainable water management and investigate effects of hydrologic responses at various scales under climate change conditions and to simulate effects of the management decisions. This study aims to assess the sustainability of water resources in the Tuul River Basin in Mongolia using SWAT (Soil Water Assessment Tool) model to understand ecohydrological processes in the basin. The model is used to analyze the trends in water usage on a watershed and subwatershed basis. The water supply and demand dynamics at each sub watershed levels are analyzed to develop a sustainability index based on specific criteria of water sustainability. Sustainability index was used for better water management by targeting areas of the watershed. Using the analysis, strategies for water demand management for the Tuul River basin area were developed. I expect the results of the study with transform water resource situation in the region through better information on the dynamics of the system and will help in alleviating water issues in similar regions of the country and of the world. The model can be a useful tool to support decision makers and to simulate and analyze the effects of water management practices.

No description available.

No description available.

No description available.

No description available.

No description available.

<p dir="ltr">Reservoirs play a vital role in water resource management, serving essential functions such as flood mitigation, water supply, power generation, and environmental conservation. In the U.S., many of these structures were constructed in the 1900s, and were primarily designed as single purpose facilities for flood risk reduction. Facing increasing threats of water shortages and groundwater depletion, the transition of these reservoirs to multi-purpose operations has never been more imperative. Operational modifications and optimizations emerge as a promising solution, offering cost-effectiveness, swift implementation, and minimal ecological disruption.</p><p dir="ltr">This dissertation advances the theory and framework of modification and optimization of reservoir operations to facilitate their transition from single to multi-purpose use. This dissertation begins with targeted optimization of static operations and progressively advances to dynamic strategies across complex multi-reservoir-river systems. This dissertation sets three primary objectives: (1) To develop a comprehensive framework for assessing the conversion potential of single-purpose reservoirs and optimizing static operation strategies for enhanced multi-purpose functionality. (2) To devise dynamic control strategies that bolster reservoir performance during extreme events through the implementation of inflow-based pre-release operations. (3) To employ a Multi-Objective Simulation-Optimization (MOSO) framework that integrates large-scale datasets and advanced optimization algorithms, optimizing multi-purpose, multi-reservoir operations in complex systems and enhancing decision-making through Multi-Criteria Decision-Making (MCDM) methods.</p><p dir="ltr">In the first objective, a robust framework is developed to evaluate and facilitate the conversion of single-purpose reservoirs into multi-purpose systems. Leveraging historical data, the proposed framework establishes Maximum Safe Water Levels (MSWLs) to optimize flood control while enhancing water supply capabilities. The methodology incorporates numerical reservoir simulation models alongside historical inflow data analysis of 15 reservoirs operated by the U.S. Army Corps of Engineers, Louisville District, all originally designed exclusively for single-purpose flood control. The findings reveal opportunities for some reservoirs to significantly increase their water supply without compromising flood management efficiency.</p><p dir="ltr">The second objective delves into dynamic control strategies for reservoir operation, with a focus on pre-release mechanisms. This objective utilizes inflow-based forecasting models to assess the impacts of different pre-release timings on flood mitigation. This study focuses on 11 of the reservoirs identified in the first objective as having potential for transition to multi-purpose use, exploring dynamic operational adjustments necessary for enhanced performance. The results show that a 72-hour pre-release lead time markedly enhanced flood control effectiveness, whereas a 24-hour lead time provides a practical compromise, achieving substantial flood mitigation with minimal adverse impacts.</p><p dir="ltr">The third objective involves developing an advanced framework utilizing the Multi-Objective Simulation-Optimization (MOSO) model and extensive datasets to optimize pre-release operations in multi-purpose reservoirs. Implementing the Non-dominated Sorting Genetic Algorithm II (NSGA-II) and Multi-Criteria Decision-Making (MCDM) methods, the framework integrates reservoir simulation models and flow routing to refine operations based on projected flood forecasts. Applied to the Green River watershed in Kentucky, this method produces Pareto-optimal solutions, elucidating the trade-offs between flood control, water supply reliability, and downstream channel performance. The results underscore the framework’s potential to significantly refine operational strategies, bolstered by sensitivity analyses that explore the effects of varying storage levels and inflow conditions, thus fostering adaptive, data-driven management for sustainable water resource optimization.</p><p dir="ltr">This dissertation contributes to the field of water resource management by demonstrating and developing innovative strategies and frameworks for the transition of single purpose reservoirs to multi-purpose systems, modifying flood control and enhancing water supply capabilities. This dissertation provides practical solutions with available data, simulation models, and optimization tools, which enable effective decision-making and operational adjustments under varying conditions. Overall, this dissertation presents a foundation for more resilient, reliable, and adaptive water management practices for reservoirs, that can meet diverse demands in a changing environmental landscape.</p>

Master of Landscape Architecture / Department of Landscape Architecture, Regional and Community Planning / Tim Keane / During a 75-year building boom starting in the early to mid 1900's we built most of the stormwater and sewage infrastructure that sustains us today. As these infrastructural systems begin to meet their life expectancy, and with our cities being impacted by flooding, rapid urbanization, and water quality concerns there is a need for designers to begin rethinking these infrastructural systems. With rapid urbanization cities are seeing increased peak flow discharge volumes within their river systems and combined sewer overflow occurrences. The River des Peres located in the City and County of Saint Louis, Missouri, is an urban waterway that is affecting the natural ecosystem and community well-being. The main stem of the River des Peres is a heavily degraded concrete trapezoidal channel that in 1988 became a National Historic Civil Engineering landmark for its sewerage and drainage works. Which leads to the question of why a historic civil engineering landmark, such as the River des Peres, is such a wreck today? In compliance with the Clean Water Act the Metropolitan St. Louis Sewer District is proposing to implement enhanced green infrastructure and stormwater/sewer storage tanks to reduce the amount of Combined Sewer Overflow (CSO) occurrences in the River des Peres watershed. However, through review of literature, site inventory and analysis, a watershed stormwater BMP plan, and corresponding site design developments it has been found that return frequency flow can be reduced as much as 56% in the watershed, reducing the need for storage tanks and reducing CSO occurrences. Through the incorporation of stormwater best management practices (BMPs) the River des Peres responds to recurrence flow, wildlife habitat, and to the well-being of the community.

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Stacy L. Hutchinson / Precipitation impacts hydrologic structures, agricultural production, water resources management, and recreational activities, all of which significantly affect a state’s economy. Water control structure design is based on the maximum runoff rate resulting from storms with a specific return period and duration. The Rainfall Frequency Atlas (National Weather Service Technical Paper 40, 1961) (TP-40) provided statistical rainfall analysis as the basis for hydrologic structure design until the information was updated for Kansas in February 2013 (National Oceanic and Atmospheric Administration Atlas 14, volume 8) (Atlas-14). With growing concern about the effects of global climate change and predictions of more precipitation and extreme weather events, it is necessary to explore rainfall distribution patterns using the most current and complete data available. In this work, the changes in rainfall patterns were studied using the daily rainfall data from 23 stations in Kansas and 15 stations from adjacent states with daily rainfall data of 1890 through 2012. Analysis showed an increase in extreme precipitation events in Kansas with increase in magnitude from the northwest to southeast part of the state. A comparison of results of the TP-40 analysis to period 1980–2009, showed that approximately 84% of the state had an increase in short-term rainfall event magnitudes. In addition, trend analyzes on the total annual rainfall indicated a gradual increase at 21 out of 23 stations, including eight statistically significant trends. A change-point analysis detected a significant sudden change at twelve stations as early as 1940 and as recently as 1980. The increasing trend, particularly after the significant change-points, is useful in updating water management plans and can assist with agricultural production decisions such as crop selection and new plant variety development. A comparison between 10-yr, 24-hr storms from TP-40 and Atlas-14 indicated a change of -12% to 5% in Kansas. However, the number of exceedances from the 10-yr, 1-, 2-, 3-, 4-, 7-, and 10-day storms demonstrated a tendency towards more exceedances, particularly in the last five decades. Results of this study are useful for hydrologic structure design and water resources management in order to prevent accepting additional risk of failure because of the current changing climate.

Water is an essential element for life and crucial to survival. South Africa is a semi-arid country and therefore water should be protected and managed effectively by all residents of the country. In the 1830s the Mooi River was the key reason for the Voortrekkers to establish Potchefstroom at a locality adjacent to this river. The Voortrekkers noticed the dolomitic outcroppings in the vicinity, but still opted to reside next to the river for it provided easily accessible water and fertile soil. Since the 1830s water legislation regulating the management and use of the water in the Mooi River has been amended innumerable times to bring us to the current situation of Potchefstroom’s water (mis)management by the role-players and stakeholders of the water source. As a resident of Potchefstroom, the researcher has a keen interest in the origin of the city’s water sources, the re-routing of the water from the origin to the water purification unit via the open-on-top cement canal system, and the overall management of these canals and their servitudes. In order to conduct a research study on the Mooi River’s water re-routing canals and servitudes, the following research methods were applied: The researcher performed a comprehensive literature review, conducted fieldwork, held interviews with landowners and experts in the geographical area of the Mooi River Valley, and performed statistical analyses as well as content analyses of the findings. Some of the most alarming findings include the lack of co-operative governance between water users and – authorities, and the current public management and disaster risk management challenges in the re-routing of water from Klerkskraal Dam down to the water purification plant of Potchefstroom. It is recommended that the major stakeholders of the Mooi River Valley, e.g. the disaster management centre in Potchefstroom, the Department of Water and Sanitation’s (DWS) regional offices in Potchefstroom, as well as the Tlokwe Local Municipality need to join forces for a combined effort to accomplish the overarching research objective of achieving improved cooperative municipal governance and Integrated Water Resources Management (IWRM) to eventually ensure the safe and effective re-routing of water from the Klerkskraal Dam to the Potchefstroom water purification plant. Note: Since July 2014 the Department of Water Affairs (DWA) has changed to the Department of Water and Sanitation (DWS). / MA (Public Management and Governance), North-West University, Potchefstroom Campus, 2015