Dissertations / Theses on the topic 'Water management; climate change'

Thesis (Ph.D)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007.<br>Committee Chair: Georgakakos, Aris; Committee Member: Fu, Rong; Committee Member: Peters-Lidard, Christa; Committee Member: Roberts, Phil; Committee Member: Sturm, Terry; Committee Member: Webster, Don.

This study evaluated the impacts of shallow and deep open drains on groundwater levels and drain performance under varying climate scenarios and irrigation application rates. The MIKE SHE model used for this study is an advanced and fully spatially distributed hydrological model. Three drain depths, climates and irrigation application rates were considered. The drains depths included 0, 1 and 2 m deep drains. The annual rainfall and meteorological data were collected from study area from 1976 to 2004 and analysed to identify the typical wet, average and dry years within the record. Similarly three irrigation application rates included 0, 10 and 16 ML/ha-annum. All together twenty seven scenarios (3 drains depths, 3 climates and 3 irrigation application rates) were simulated. The observed soil physical and hydrological data were used to calibrate and validate the model. Mean square error (R[superscript]2) of the simulated and observed water table data varied from 0.7 to 0.87. Once validated the MIKE SHE model was used to evaluate the effectiveness of 1 and 2 metre deep drains. The simulated water table depth, unsaturated zone deficit, exchange between unsaturated and saturated zones, drain outflow and overland flow were used to analyse their performance. The modeling results showed that the waterlogging was extensive and prolonged during winter months under the no drainage and no irrigation scenario. In the wet climate scenario, the duration of water logging was longer than in the average climate scenario during the winter months. In the dry climate scenario no waterlogging occurred during the high rainfall period. The water table reached soil surface during the winter season in the case of wet and average climate. For the dry climate, the water table was about 0.9 metres below soil surface during winter.<br>One and 2 metre deep drains lowered the water table up to 0.9 and 1.8 metres in winter for the wet climate when there was no irrigation application. One metre deep drains proved effective in controlling water table during wet and average climate without application of irrigation water. One metre deep drains were more effective in controlling waterlogging a in wet, average and dry years when the irrigation application rate was 10 ML/ha-annum. With 16 ML/ha-annum irrigation application, 1 metre deep drains did not perform as efficiently as 2 metre deep drains in controlling the water table and waterlogging. In the dry climate scenario, without irrigation application, 1 metre deep drains were not required as there was not enough flux from rainfall and irrigation to raise the water table and create waterlogging risks. Two metre deep drains lowered the water table to greater depths in the wet, average and dry climate scenarios respectively when no irrigation was applied. They managed water table better in wet and average climate with 10 and 16 ML/ha-annum irrigation application rate. Again in the dry climate, without irrigation application 2 metre deep drains were not required as there was a minimal risk of waterlogging. The recharge to the groundwater table in the no drainage case was far greater than for the 1 and 2 metre deep drainage scenarios. The recharge was higher in case of 1 metre deep drains than 2 metre deep drains in wet and average climate during winter season.<br>There was no recharge to ground water with 1 and 2 metre deep drains under the dry climate scenarios and summer season without irrigation application as there was not enough water to move from the ground surface to the unsaturated and saturated zones. When 10 ML/ha-annum irrigation rate was applied during wet, average and dry climate respectively, 1 metre deep drains proved enough drainage to manage the recharge into the groundwater table with a dry climate. For the wet and average climate scenarios, given a 10 ML/ha-annum irrigation application rate, 2 metre deep drains managed recharge better than 1 metre deep drains. Two metres deep drains with a 10 ML/ha-annum irrigation application rate led to excessive drainage of water from the saturated zone in the dry climate scenario. Two metres deep drains managed recharge better with a 16 ML/ha-annum irrigation application rate in the wet and average climate scenarios than the 1 metre deep drains. Two metres deep drains again led to excessive drainage of water from the saturated zone in dry climate. In brief, 1 metre deep drains performed efficiently in the wet and average climate scenarios with and without a 10 ML/ha-annum irrigation application rate. One metre deep drains are not required for the dry climate scenario. Two metre deep drains performed efficiently in the wet and average climate scenarios with 16 ML/ha-annum irrigation application rate. Two metre deep drains are not required for the dry climate scenario.

Water is recognised as a key driver for social and economic development in the Zambezi basin. The basin is riparian to eight southern African countries and the transboundary nature of the basin’s water resources can be viewed as an agent of cooperation between the basin countries. It is possible, however, that the same water resource can lead to conflicts between water users. The southern African Water Vision for ‘equitable and sustainable utilisation of water for social, environmental justice and economic benefits for the present and future generations’ calls for an integrated and efficient management of water resources within the basin. Ensuring water and food security in the Zambezi basin is, however, faced with challenges due to high variability in climate and the available water resources. Water resources are under continuous threat from pollution, increased population growth, development and urbanisation as well as global climate change. These factors increase the demand for freshwater resources and have resulted in water being one of the major driving forces for development. The basin is also vulnerable due to lack of adequate financial resources and appropriate water resources infrastructure to enable viable, equitable and sustainable distribution of the water resources. This is in addition to the fact that the basin’s economic mainstay and social well-being are largely dependent on rainfed agriculture. There is also competition among the different water users and this has the potential to generate conflicts, which further hinder the development of water resources in the basin. This thesis has focused on the Zambezi River basin emphasising climate variability and climate change. It is now considered common knowledge that the global climate is changing and that many of the impacts will be felt through water resources. If these predictions are correct then the Zambezi basin is most likely to suffer under such impacts since its economic mainstay is largely determined by the availability of rainfall. It is the belief of this study that in order to ascertain the impacts of climate change, there should be a basis against which this change is evaluated. If we do not know the historical patterns of variability it may be difficult to predict changes in the future climate and in the hydrological resources and it will certainly be difficult to develop appropriate management strategies. Reliable quantitative estimates of water availability are a prerequisite for successful water resource plans. However, such initiatives have been hindered by paucity in data especially in a basin where gauging networks are inadequate and some of them have deteriorated. This is further compounded by shortages in resources, both human and financial, to ensure adequate monitoring. To address the data problems, this study largely relied on global data sets and the CRU TS2.1 rainfall grids were used for a large part of this study. The study starts by assessing the historical variability of rainfall and streamflow in the Zambezi basin and the results are used to inform the prediction of change in the future. Various methods of assessing historical trends were employed and regional drought indices were generated and evaluated against the historical rainfall trends. The study clearly demonstrates that the basin has a high degree of temporal and spatial variability in rainfall and streamflow at inter-annual and multi-decadal scales. The Standardised Precipitation Index, a rainfall based drought index, is used to assess historical drought events in the basin and it is shown that most of the droughts that have occurred were influenced by climatic and hydrological variability. It is concluded, through the evaluation of agricultural maize yields, that the basin’s food security is mostly constrained by the availability of rainfall. Comparing the viability of using a rainfall based index to a soil moisture based index as an agricultural drought indicator, this study concluded that a soil moisture based index is a better indicator since all of the water balance components are considered in the generation of the index. This index presents the actual amount of water available for the plant unlike purely rainfall based indices, that do not account for other components of the water budget that cause water losses. A number of challenges were, however, faced in assessing the variability and historical drought conditions, mainly due to the fact that most parts of the Zambezi basin are ungauged and available data are sparse, short and not continuous (with missing gaps). Hydrological modelling is frequently used to bridge the data gap and to facilitate the quantification of a basin’s hydrology for both gauged and ungauged catchments. The trend has been to use various methods of regionalisation to transfer information from gauged basins, or from basins with adequate physical basin data, to ungauged basins. All this is done to ensure that water resources are accounted for and that the future can be well planned. A number of approaches leading to the evaluation of the basin’s hydrological response to future climate change scenarios are taken. The Pitman rainfall-runoff model has enjoyed wide use as a water resources estimation tool in southern Africa. The model has been calibrated for the Zambezi basin but it should be acknowledged that any hydrological modelling process is characterised by many uncertainties arising from limitations in input data and inherent model structural uncertainty. The calibration process is thus carried out in a manner that embraces some of the uncertainties. Initial ranges of parameter values (maximum and minimum) that incorporate the possible parameter uncertainties are assigned in relation to physical basin properties. These parameter sets are used as input to the uncertainty version of the model to generate behavioural parameter space which is then further modified through manual calibration. The use of parameter ranges initially guided by the basin physical properties generates streamflows that adequately represent the historically observed amounts. This study concludes that the uncertainty framework and the Pitman model perform quite well in the Zambezi basin. Based on assumptions of an intensifying hydrological cycle, climate changes are frequently expected to result in negative impacts on water resources. However, it is important that basin scale assessments are undertaken so that appropriate future management strategies can be developed. To assess the likely changes in the Zambezi basin, the calibrated Pitman model was forced with downscaled and bias corrected GCM data. Three GCMs were used for this study, namely; ECHAM, GFDL and IPSL. The general observation made in this study is that the near future (2046-2065) conditions of the Zambezi basin are expected to remain within the ranges of historically observed variability. The differences between the predictions for the three GCMs are an indication of the uncertainties in the future and it has not been possible to make any firm conclusions about directions of change. It is therefore recommended that future water resources management strategies account for historical patterns of variability, but also for increased uncertainty. Any management strategies that are able to satisfactorily deal with the large variability that is evident from the historical data should be robust enough to account for the near future patterns of water availability predicted by this study. However, the uncertainties in these predictions suggest that improved monitoring systems are required to provide additional data against which future model outputs can be assessed.

It is no longer a question of scientific debate that research declares our climate is changing. One of the most important and visible impacts of this phenomenon is sea level rise which has impacts on coastal cities and island communities. Sea level rise also magnifies storm surges which can have severely damaging impacts on different human made infrastructure facilities near the shorelines in coastal zones. In this research we are concerned about the proximity of water systems as one of the most vulnerable infrastructures in the coastal zones because of the impact of stormwater combining with sewage water. In Canada, the government has plans to address these issues, but to date, there needs to be further attention to stormwater management in coastal zones across the country. This research discusses the impacts of severe environmental events, e.g., hurricanes and storm surge, on the water systems of selected coastal communities in Canada. The purpose of this research is to model coastal zone water systems using the open source StormWater Management Modelling (SWMM) software in order to manage stormwater and system response to storms and storm surge on water treatment plants in these areas. Arichat on Isle Madame, Cape Breton, one of the most sensitive coastal zones in Canada, is the focal point case study for this research as part of the C-Change International Community-University Research Alliance (ICURA) 2009-2015 project.

Climate change is experienced most through the medium of water. The ability of water institutions and the factors that enable or hinder them to purposefully adapt to the new and additional challenges brought by climate change require better understanding. Factors that influence their perception of climate change impacts and initiatives being taken for adaptation are shaped by various enabling factors and barriers through the interaction with both governmental and non-governmental institutions across administrative scales. Better understanding of these adaptation enablers and barriers is essential for devising adaptation strategies. This research aims to identify and expound the characteristics that enable or hinder institutions to adapt for water management, and hence, it evaluates the involvement of key governmental and non-governmental institutions in India and the inter-institutional networks between them. It surveyed webpages and online documents of sixty Union Government institutions and interviewed representatives from twenty-six governmental, non-governmental, research and academic institutions operating at the national level and another twenty-six institutions operating within the State of Himachal Pradesh in India to assess the characteristics that enable or hinder adaptation. While the online projection of institutional involvement and interaction among key Union Government institutions on climate change and water indicate a more centralized network pointing to Planning Commission and Ministry of Environment and Forest, the interview responses indicated a more distributed network with both Ministries of Water Resources and Environment and Forest recognized as key institutions thereby indicating a potential variation in perception of who is in-charge. Moreover, online documents show institutions that are involved in water have less mention of climate change compared to Union Government ministries involved in less climate-sensitive sectors indicating that impacts of climate change on water are potentially ignored. While it is evident that research and consulting institutions engaging with both national and state level institutions play a key role in enabling adaptation, various barriers pertaining to data and information accessibility, inadequacy of resources and implementation gaps exist particularly due to inter-institutional network fragmentations. Although barriers identified in this study bear resemblance to barriers identified by other researchers in other contexts, this research shows similar barriers can emerge from different underlying causes and are highly interconnected; thereby indicating the need for addressing adaptation barriers collectively as a wider governance issue. Since many of the adaptation barriers emerge from wider governance challenges and are related to larger developmental issues, the findings have important policy implications. Among the various issues that the government needs to address is improving the inter-institutional networks between water institutions so that information dissemination, sharing of learning experiences and data accessibility is improved and prescriptive legislations are seen to be inadequate in this regard. Restructuring the way officials in government water institutions are recruited and deployed is suggested as a potential solution for improving the inter-institutional networks. The research elucidates that inter-institutional networks and transboundary institutions are two pillars that supports adaptation and also bridges the gap between adaptive capacity and adaptation manifestation that enable water institutions to cross the chasm of adaptation barriers. Thus the thesis presents an important analysis of key characteristics that enable or hinder water management institutions to adapt to climate change which have been so far under acknowledged by other studies through the analysis of the state of climate change adaptation in India. Therefore, this study provides valuable insights for developing countries, particularly, facing similar challenges of adapting water management for climate change.

Environmental management is plagued with uncertainty, despite this, little attention has until recently been given to the sensitivity of management decisions to uncertain environmental projections. Assuming that the future climate is stationary is no longer considered valid, nor is using a single or small number of potentially incorrect projections to inform decisions. Instead, it is recommended that decision makers make use of increasingly available probabilistic projections of future climate change, such as those from perturbed physics ensembles like United Kingdom Climate Projections 2009 (UKCP09), to gauge the severity and extent of future impacts and ultimately prepare more robust solutions. Two case studies focussing on contrasting aspects of local water management; namely irrigation demand and urban drainage management, were used to evaluate current approaches and develop recommendations and improved methods of using probabilistic projections to support decision making for climate change adaptation. A quantitative understanding of the impact of uncertainty to decision making for climate change adaptation was obtained from a literature review; followed by a comparison of using (1) the low medium and high emission scenarios, (2) 10,000 sample ensemble and 11 Spatially Coherent Projections (11SCP), (3) deterministic and probabilistic climate change projections, (4) the complete probabilistic dataset and sub-samples of it using different sampling techniques, (5) the change factor (or delta change) and stochastic (or UKCP09 weather generator) downscaling techniques and (6) different decision criteria using two contrasting case studies at three UK sites. This research provides an insight into the impact of different sources of uncertainty to real-world adaptation and explores whether having access to more data and a greater appreciation of uncertainty alters the way we make decisions. The impact of the “envelope of uncertainty” to decision making is explored in order to identify those factors and decisions that have the greatest impact on what we perceive to be the “best” solution. An improved novel decision criterion for use with probabilistic projections for adaptation planning is presented and tested using simplified real-world case studies to establish whether it provides a more attractive tool for decision makers compared to the current decision criteria which have been advocated for adaptation planning. This criterion explicitly incorporates the unique risk appetite of the individual into the decision making process, acknowledging that this source of uncertainty and not necessarily the climate change projections, had the greatest impact on the decisions considered by this research. This research found the differences between emission scenarios, projection datasets, sub-sampling approaches and downscaling techniques, each contributing a different source of uncertainty, tended to be small except where the decision maker already exhibited an extremely risk seeking or risk adverse appetite. This research raises a number of interesting questions about the “decision significance” of uncertainty through the systematic analysis of several different sources of uncertainty on two contrasting local water management case studies. Through this research, decision makers are encouraged to take a more active role in the climate change adaptation debate, undertaking their own analysis with the support of the scientific community in order to highlight those uncertainties that have significant implications for real world decisions and thereby help direct future efforts to characterise and reduce them. The findings of this research are of interest to planners, engineers, stakeholders and adaptation planning generally.

xi, 129 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.<br>Climate change is disrupting the underpinnings of effective water management by profoundly impacting hydrological patterns. Political entities mandated with freshwater management must respond to society's water needs as availability fluctuates and, in doing so, will encounter difficult ethical dilemmas because existing water laws are ill-equipped to resolve such problems. This thesis takes Chile's water laws as representative of the challenges in addressing ethical disparities arising from freshwater management in a changing climate and proposes that "water ethics" can effectively be used to manage freshwater resources. I examine the 1981 Water Code with a critical eye towards ethical shortcomings and also examine distributive impacts upon indigent farmers and indigenous communities. I conclude that Chile's existing water laws are inequitable because they deny legitimacy to diverse socio-cultural norms regarding water use. Principles of modern water laws must incorporate diverse cultural water laws using a legally pluralistic and ethical approach to management.<br>Committee in Charge: Dr. Anita M. Weiss, Chair; Professor Derrick Hindery; Professor Stuart Chinn

While much attention has been given to the ways local communities may be impacted by climate change, this dissertation focuses ethnographically on the local agencies decision-making processes, a less-studied aspect of this topic. The primary purpose of this dissertation research is to understand how government agencies in southern Florida integrate climate change into their decision-making processes while dealing with political resistance. This research expands our understanding on the cultural politics of a new kind of environmental change, where national and international climate-change politics is brought into local water politics to illuminate how new and not so new visions about life in the contemporary metropolis collide and collude. Using multiple research methods including ethnographic fieldwork, participant observation, semi-structured interviews, and document research, I analyze the activities of the Miami-Dade County Climate Change Advisory Task Force Committee (MDC-CCATF) as well as the water management practices of the regional water management agency, the South Florida Water Management District (SFWMD). My findings include the following: (1) the Task Force activities have spearheaded Miami’s institutional adaptation to climate change; (2) historic legacies have expanded and complicated decision-making processes at the District; (3) a focus on the certainties of climate-change science allows climate change to persist in politically contentious planning contexts. My dissertation concluded that while planning for potential climate-change impacts can be difficult due to multiple institutional constraints that resource agencies like the District have, scientists and policy-makers have crafted an innovative culture that is particularly visible at sites where science and decision making intersect.

Recent prolonged droughts make the urgent need to revise the criteria for water use permits in Brazil, especially in basins under conflicts for water use. Mechanisms for water risks transfer are an important adaptation tool. However, in Brazil, there is no established methodology that adapts this technique to assist the water use permit instrument. Moreover, there is no water risk insurance methodology with uncertainty analysis that complements its effectiveness in reducing losses from extreme events. Hydrologic modelling is the basis for development of these tools, which carries uncertainties that must be considered in decision-making. The objectives of this project were: i&#41; coupling climatic, hydrologic and water insurance models to evaluate the use permit decision-making; ii&#41; analyse sensitivity of performance indicators of a water risk insurance model through the application of different hydrologic models driven by climate change projections. The methodology was applied in donor basins of the Cantareira Water Supply System, which supplies water to an important metropolitan region that showed itself vulnerable to hydrologic extremes in the last years. The MHD-INPE and SWAT hydrologic models were applied, driven by the Eta- HadGEM2-ES climate model projections to characterize the future hydrologic regime in the region and also to compare the structure, performances and gaps of the models. Structural differences are most likely the greater responsible for the results differences, though no result could be identified as \"more certain\". With the hydrologic models outputs fitted the the Gumbel extreme values distribution, a proposed insurance fund simulator, MTRH-SHS, was run with 100 equiprobable scenarios of 50-year annual low-flow events to calculated an optimized premium capable of paying all indeminities of hydrologic drought. Besides the future hydrologic regimes, water demand scenarios were also tested. The optimized premiums were compared to the local GDP to assess the apparent affordability of the insurance, with some premium representing up to 0.54&#37; of local GDP, but in the water resources management framework, the decision should be made collectively by several actors within the basin&#39;s committee.<br>Recentes estiagens fazem reconsiderar a necessidade de aperfeiçoar critérios de outorga de água no Brasil, especialmente em bacias com conflitos pelo uso da água. Seguros &#40;transferência de risco&#41; são importante ferramenta de adaptação. Contudo, no Brasil ainda não há metodologia consolidada que adapte esta técnica para auxiliar o instrumento de outorga de recursos hídricos. Ainda, não há metodologia de seguros hídricos com análise de incertezas, complementando sua efetividade ao reduzir os prejuízos advindos de eventos extremos. Modelos hidrológicos são a base de desenvolvimento destas ferramentas e carregam incertezas que devem ser integralizadas nos processos de decisão. Os objetivos deste projeto foram: i&#41; acoplar modelos: climático, hidrológico e de seguros hídricos para a avaliação do processo de decisão de outorga; ii&#41; realizar análise de sensibilidade dos indicadores de desempenho de modelo de seguros hídricos com diferentes modelos hidrológicos sob cenários de mudanças do clima. A metodologia foi aplicada nas bacias doadoras do Sistema Cantareira, que abastece importante região metropolitana e mostrou-se vulnerável a extremos hidrológicos nos últimos anos. Os modelos hidrológicos MHD-INPE e SWAT foram aplicados, forçados pelas projeções climáticas do modelo Eta-HadGEM2-ES a fim de caracterizar o regime hidrológico future na região, assim como comparar a estrutura, diferenças e performances dos modelos hidrológicos. As diferenças estruturais são provavelmente as maiores responsáveis pela diferença nos resultados, embora não seja possível apontar um modelo &#34;melhor&#34; que o outro. As saídas dos modelos foram ajustadas na distribuição de Gumbel e utilizada no modelo proposto de simulação de fundo de seguros, MTRH-SHS, rodado com 100 séries equiprováveis de 50 anos de eventos mínimos anuais. A cada série um prêmio otimizado é calculado para cobrir todas as indenizações de seca hidrológica. Além das projeções hidrológicas, cenários de demanda foram testados. Os prêmios otimizados foram comparados com o PIB local para demonstrar a viabilidade em implementar o seguro. Os valores representam até 0.54&#37; do PIB local em um dos casos, mas na gestão de recursos hídricos, a decisão final pela implementação deve ser feita no âmbito do comitê de bacias por múltiplos atores.

Forecasted changes to climate and land use were used to model variations in the streamflow characteristics of Occoquan watershed and water quality in the Occoquan reservoir. The combination of these two driving forces has created four themes and an integrated complexly-linked watershed-reservoir model was used to run the simulations. Two emission scenarios from the fourth assessment report of the Intergovernmental Panel on Climate Change (IPCC), along with four General Circulation Models (GCMs) by using two statistical downscaling methods, were applied to drive the Hydrological Simulation Program - Fortran (HSPF) and CE-QUAL-W2 (W2) in two future time periods (2046-2065 and 2081-2100). Incorporation of these factors yielded 68 simulation models which were compared with historical streamflow and water quality data from the late 20th century. Climate change is projected to increase surface air temperature and precipitation depth in the study area in the future. Using climate change only, an increase in high and median flows and decrease in low flows are projected. Changes in flow characteristics are more pronounced when only future land use changes are considered, with increases in high, median and low flows. Under the joint examination of the driving forces, an amplifying effect on the high flows and median flows observed. In contrast, climate change is projected to dampen the extreme increases in the low flows created by the land use change. Surface water temperatures are projected to increase as a result of climate change in the Occoquan reservoir, while these changes are not very noticeable under the effect of land use change only. It is expected that higher water temperatures will promote decreased oxygen solubility and greater heterotrophy. Moreover, longer anoxic conditions are projected at the bottom of the reservoir. Results indicate that higher water temperature will increase the denitrifying capacity of the reservoir, especially during summer months, further reducing the nitrate concentration in the reservoir.<br>PHD

This thesis examines how climate change is being integrated within India's national and state government water policy and management practices. Climate change poses significant challenges to the management of non-stationary hydro-meteorological conditions, whilst meeting rising water demand. The nature and orientation of the Indian government's water institutional approach compounds this challenge, due to the1r focus on large-scale infrastructure-based supply-side water management. This research takes an interdisciplinary political ecology approach to examine the Indian hydrocracy's response, namely, the Ministry of Water Resources' (MWR) policy response to climate change, and the state level response by the Andhra Pradesh (AP) Irrigation Department. The analysis is based on policy documents and other government reports, interviews with policy makers and water managers, and non-government water experts 1n India, conducted between 2008 and 2011. The research draws on theoretical groundings of the linear and interactive models to understand public policy processes, water management paradigms including the hydraulic mission, river basin trajectory and institutional reform theory to understand the process and pace of government change. The Indian water policy experience will generate insights into the use of water policy to respond to climate change. The results indicate that climate change is being integrated within policy and water management practices as a continuation of infrastructure-based supply approaches to water management. This approach is facilitated by the uncertainty of climate change projections and impacts, which provide plasticity for it to be used to strengthen a sanctioned 'water for food' government discourse and hence continue India's hydraulic mission. The MWR and AP Irrigation Department appear resistant to change their strategic approach to water management. However, certain reformist actors within the margins of government are endeavouring to operationalise demand management strategies and institutional reform measures, broadly representing a reflexive modernity stage of water management. Insights into the Indian water policy process highlight numerous challenges to implementation, consistent with an interactive theoretical model of public policy. Implementation challenges of paramount importance include the politically contested nature of water management which serves vested political and financial interests, and the inertia of government, characterised by centralised and hierarchical structures and procedures. The government appears to be operating within the limits of a linear theoretical model of public policy, recommending demand management and institutional reform 'statements of policy intent', but without offering a suitable institutional approach to address implementation challenges. The hydrocracy is largely permitted to continue its approach within the wider political context in India, with other actors implicitly supporting and benefiting from large-scale water infrastructure. In conclusion, this research finds that both continuity and change co-exist within government water management in India. Resistance to change endures, whilst at the same time, certain reformist actors are intent to navigate the complex and uncertain nature of institutional reform.

Water managers for the City of Phoenix face the need to make informed policy decisions regarding long-term impacts of climate change on the Salt-Verde River basin. To provide a scientifically informed basis for this, we estimate the evolution of important components of the basin-scale water balance through the end of the 21st century. Bias-corrected and spatially downscaled climate projections from the Phase-3 Coupled Model Intercomparison Project of the World Climate Research Programme were used to drive a spatially distributed variable infiltration capacity model of the hydrologic processes in the Salt-Verde basin. From the many Global Climate Model's participating in the IPCC fourth assessment, we selected a five-model ensemble, including three that best reproduce the historical climatology for our study region, plus two others to represent wetter and drier than model average conditions; the latter two were requested by City of Phoenix water managers to more fully represent the full range of GCM prediction uncertainty. For each GCM, data for three emission scenarios (A1B, A2, B1) was used to drive the hydrologic model into the future. The model projections indicate a statistically significant 25% decrease in streamflow by the end of the 21st century. Contrary to previous assessments, this is not caused primarily by changes in the P/E ratio, but is found to result mainly from decreased winter precipitation accompanied by significant (temperature driven) reductions in storage of snow. The results show clearly the manner in which water management in central Arizona is likely to be impacted by changes in regional climate.

This dissertation explores the impact of climate change and extreme weather events on critical infrastructures as defined by US Department of Homeland Security. The focus is on two important critical infrastructure systems – Water and Transportation. Critical infrastructures are always under the risk of threats such as terrorist attacks, natural disasters, faulty management practices, regulatory policies, and defective technologies and system designs. Measuring the performance and risks of critical infrastructures is complex due to its network, geographic and dynamic characteristics and multiplicity of stakeholders associated with them. Critical infrastructure systems in crowded urban and suburban areas like the Washington Metropolitan Area (WMA) are subject to increased risk from geographic proximity. Moreover, climate is challenging the assumption of stationary (the idea that natural systems fluctuate within an unchanging envelope of variability) that is the foundation of water resource engineering and planning. Within this context, this research uses concepts of systems engineering such as 'systems thinking' and 'system dynamics' to understand, analyze, model, simulate, and critically assess a critical infrastructure system's vulnerability to extreme natural events and climate change. In most cases, transportation infrastructure is designed to withstand either the most extreme or close to the most extreme event that will add abnormal stresses on a physical structure. The system may fail to perform as intended if the physical structure faces an event larger than what it is designed for. The results of the transportation study demonstrate that all categories of roadways are vulnerable to climate change and that the magnitude of bridge vulnerability to future climate change is variable depending on which climate model projection is used. Results also show that urbanization and land use patterns affects the susceptibility of the bridge to failures. Similarly, results of the water study indicate that the WMA water supply system may suffer from water shortages accruing due to future droughts but climate change is expected to improve water supply reliability due to an upward trend in precipitation and streamflow.<br>Ph. D.

The exponential growth of the world population led by the geographic expansion of urban areas in developing countries has put massive pressure on natural resources especially land and water. Water supply and water scarcity remain one of the major challenges facing the industrializing world. The United Nations forecast further increase in population which, in the absence of management and policies, will inevitably put more resources at risk. Changing climatic conditions causing more frequent and intense rainfall will also affect water management systems in the vulnerable urban areas of developing countries. The goal of this study was twofold; first analyze the patterns of water consumption in the rapidly growing city of Lagos, Nigeria and use them in a System Dynamics (SD) model to make projections about future demand. The second part used remote sensing to quantify the contribution of extensive land use/cover change to urban flooding. Land use/cover dynamics over the past decade was analyzed using satellite imagery provided by Landsat Thematic Mapping (TM). Unsupervised classification was performed with false color composite using the Iterative Self-Organizing Data Analysis (ISODATA) technique in a Geographic Information Systems (GIS). The study area was divided into four different land use types during image classification: bare land, built-up area, water bodies, and vegetation. For water demand, two different scenarios of population growth including 5.5% and 2.75 % annual increase were considered. The results showed that water demand dropped by 67% of its current value when losses in distribution were reduced by 20% and population annual growth rate kept at 2.75% over the study period. Bare land and water bodies lost 1.31% and 1.61% of their current area respectively while built-up area grew by 1.11%. These changes in land use/cover changes led to a 64% increase in average surface runoff, mostly attributable to increasing surface imperviousness and the absence of an adequate urban drainage system. This paper intends to assist the authorities of the city of Lagos who adopted a master plan in 2010 as a road map to reduce to city’s vulnerability to flooding and close the gap between water demand and water supply by 2050.

Applications of the SWAT model typically involve delineation of a watershed into subwatersheds/subbasins that are then further subdivided into hydrologic response units (HRUs) which are homogeneous areas of aggregated soil, landuse, and slope and are the smallest modeling units used within the tool. In a standard SWAT application, multiple potential HRUs (farm fields) in a subbasin are usually aggregated into a single HRU feature. In other words, the standard version of the model combines multiple potential HRUs (farm fields) with the same landuse/landcover (LULC), soil, and slope, but located in different places within a subbasin (spatially non-unique), and considers them as one HRU. In this study, ArcGIS pre-processing procedures were developed to spatially define a one-to-one match between farm fields and HRUs (spatially unique HRUs) within a subbasin prior to SWAT simulations to facilitate input processing, input/output mapping, and further analysis at the individual farm field level. Model input data such as LULC, soil, crop rotation and other management data were processed through these HRUs. The SWAT model was then calibrated/validated for the Raccoon River watershed in Iowa for 2002 to 2010 and the Big Creek River watershed in Illinois for 2000 to 2003. SWAT was able to replicate annual, monthly and daily streamflow, as well as sediment, nitrate and mineral phosphorous within recommended accuracy in most cases. The one-to-one match between farm fields and HRUs created and used in this study is a first step in performing LULC change, climate change impact, and other analyses in a more spatially explicit manner. The calibrated and validated SWAT model was then used to assess agricultural scenario and climate change impacts on watershed water quantity, quality, and crop yields. Modeling impacts of agricultural scenarios and climate change on surface water quantity and quality provides useful information for planning effective water, environmental, and land use policies. Despite the significant impacts of agriculture on water quantity and quality, limited literature exists modeling the combined impacts of agricultural scenarios and climate change on crop yields and watershed hydrology. Here, SWAT, was used to model the combined impacts of five agricultural scenarios and three climate scenarios downscaled using eight climate models. These scenarios were implemented in a well calibrated SWAT model for the Raccoon River watershed (RRW), IA. We run the scenarios for the historical baseline, early-century, mid-century, and late-century periods. Results indicate that historical and more corn intensive agricultural scenarios with higher CO2 emissions consistently result in more water in the streams and greater water quality problems, especially late in the 21st century. Planting more switchgrass, on the other hand, results in less water in the streams and water quality improvements relative to the baseline. For all given agricultural landscapes simulated, all flow, sediment and nutrient outputs increase from early-to-late century periods for the RCP4.5 and RCP8.5 climate scenarios. We also find that corn and switchgrass yields are negatively impacted under RCP4.5 and RCP8.5 scenarios in the mid and late 21st century. Finally, various agricultural best management practice (BMP) scenarios were evaluated for their efficiency in alleviating watershed water quality problems. The vast majority of the literature on efficiency assessment of BMPs in alleviating water quality problems base their scenarios analysis on identifying subbasin level simulation results. In the this study, we used spatially explicit HRUs, defined using ArcGIS-based pre-processing methodology, to identify Nitrate (NO3) and Total Suspended Solids (TSS) hotspots at the HRU/field level, and evaluate the efficiency of selected BMPs in a large watershed, RRW, using the SWAT model. Accordingly, analysis of fourteen management scenarios were performed based on systematic combinations of five agricultural BMPs (fertilizer/manure management, changing cropland to perennial grass, vegetative filter strips, cover crops and shallower tile drainage systems) aimed to reduce NO3 and TSS yields from targeted hotspot areas in the watershed at field level. Moreover, implications of climate change on management practices, and impacts of management practices on water availability and crop yield and total production were assessed. Results indicated that either implementation of multiple BMPs or conversion of an extensive area into perennial grass may be required to sufficiently reduce nitrate loads to meet the drinking water standard. Moreover, climate change may undermine the effectiveness of management practices, especially late in the 21st century. The targeted approach used in this study resulted in slight decreases in watershed average crop yields, hence the reduction in total crop production is mainly due to conversion of croplands to perennial grass.

Climate change is projected to impact the hydrological cycle and have a negative effect on water supply. In South Africa, water to the end user is supplied by local municipalities, and thus municipalities are likely to benefit from adapting to these climate impacts. This research aims to understand the views and behaviours of local municipal actors towards water management and climate change, and how these views and behaviours influence the resilience of their water supply system in the face of climate change. A secondary aim of the thesis was to determine if the advice networks, where the actors receive the bulk of their information from, influenced the actor’s views and behaviours around water management, climate change, and adaptation, using a social network approach. The study area focused on five local municipalities in the West Coast District of South Africa. This research made use of a mixed methods approach, utilising both qualitative and quantitative data, obtained using semi-structured interviews with a structured component. Qualitative data were used to collect water management-related views and behaviours of municipal actors, whilst quantitative data were collected to determine social network characteristics. The views and behaviours on water demand and supply management of the actors interviewed tended to differ. Actors’ views on ideal water management approaches were more concerned with the long-term sustainability of water resources through raising awareness and managing existing infrastructure better. Actor’s preferred behaviours however focused on immediate relief to water shortages, by augmenting existing supply and enforcing restrictions. These findings imply that actors respond reactively to drought, and not proactively. In terms of climate change, actors showed a clear understanding of climate change and its risks to water management. Actors understood how climate change adaptation could be used to make their municipalities’ water supply more resilient, by utilising sustainable sources of water or through ecosystem-based adaptation, however it was found that municipal plans and behaviours did not generally reflect these views. Social network characteristics such as strengths of ties, and the existence of multiplex ties, did not appear to influence the sharing of behaviours or views between the actor and their given advice network. It was thus theorised that institutional lock-in and hierarchical governance might play a larger role in influencing views and behaviours than the actors’ social networks. The reactive responses by actors to issues of water demand or supply can lead to poor resilience in the face of climate change, where cases of drought and water shortages may become more frequent. Whilst municipal actors are aware of these changing conditions and risks, the limitations placed on them by governance structures and lock-in impact their ability to be proactive. More work needs to be done to ensure sustainable and resilient water management interventions are implemented at the local municipal level. Additionally, lockin, both institutional and technological, could usefully be challenged to allow for innovative ideas to enter the realm of water management at the local municipal level.

Water management plans are typically developed using historical data records and historical return periods for extreme events, such as floods or droughts. Since these analyses of return periods typically assume a certain degree of stationarity (constant mean, standard deviation, distribution) in hydrologic variables, the potential future impacts of climate change are excluded. In developing water management plans, predicted changes to climate variables should be considered to evaluate the degree of non-stationarity that may exist in the future. In this way, regions most sensitive to climate change can be identified and managed appropriately. This study performed such a task by using predicted climate data that were downscaled from general circulation models (GCM) by regional climate models (RCM) to compare climate variables in the historical period of 1971-1998 to the future period of 2041-2068. The study evaluated the precipitation and minimum/maximum temperature data from five different GCM/RCM combinations: 1) CCSM/CRCM; 2) CCSM/WRFG; 3) CGCM3/CRCM; 4) CGCM3/WRFG; and 5) HadCM3/HRM3. The five datasets were then used to calculate drought indices and drive a calibrated PRMS model of the Molalla Pudding river basin in order to evaluate changes in droughts and streamflow. The predicted changes in droughts and streamflow were then evaluated with social/economic factors for twelve cities in the Molalla Pudding river basin by two different water vulnerability indices. The index values were used to determine a rank for each city that indicated its relative vulnerability to water scarcity as compared to the other cities. In this study, three out of the five datasets predicted increased precipitation (+97-115 mm/year) over the Molalla Pudding basin and the two datasets using the CCSM GCM data predicted either no change or slightly decreased precipitation (-60 mm/year) over the Molalla Pudding basin in 2041-2068. All datasets predicted increased minimum and maximum average temperature of +1.5°C and +1.4°C respectively, and all datasets displayed increasing trends in temperature. The drought indices predicted fewer drought events (-2.4 events) over 2041-2068 with no change in duration, and no change to the number of serious drought events over 2041-2068 but with increased durations (+1.9 months). Results from the hydrologic modeling predicted increased streamflow (+4-249 cfs) in four out of the five future datasets. Using the predicted changes in hydrologic variables and social/economic census data from 2000, two types of water vulnerability indices were calculated for the twelve cities of interest. The results suggested that cities in the western portion of the basin would be more susceptible to current and future water vulnerability due to high irrigation demands for water and high social vulnerability as determined by minority populations and higher poverty, while the small cities with less dependence on agriculture would be less vulnerable.

Climate change impacts hydrology, nutrient cycling, agricultural conservation practices, and greenhouse gas (GHG) emissions. The Chesapeake Bay and its watershed are subject to the largest and most expensive Total Maximum Daily Load (TMDL) ever developed. It is unclear if the TMDL can be met given climate change and variability (e.g., extreme weather events). The objective of this dissertation is to quantify the impact of climate change and climate on water resources, nutrient cycling and export in agroecosystems, and agricultural conservation practices in the Chesapeake Bay watershed. This is accomplished by developing and employing a suite of modelling tools. GHG emissions from agroecosystems, particularly nitrous oxide (N2O), are an increasing concern. To quantify N2O emissions a routine was developed for the Soil and Water Assessment Tool (SWAT) model. The new routine predicts N2O and di-nitrogen (N2) emissions by coupling the C and N cycles with soil moisture, temperature, and pH in SWAT. The model uses reduction functions to predict total denitrification (N2 + N2O production) and partitions N2 from N2O using a ratio method. The SWAT nitrification routine was modified to predict N2O emissions using reduction functions. The new model was tested using GRACEnet data at University Park, Pennsylvania, and West Lafayette, Indiana. Results showed strong correlations between plot measurements of N2O flux and the model predictions for both test sites and suggest that N2O emissions are particularly sensitive to soil pH and soil N, and moderately sensitive to soil temperature/moisture and total soil C levels. The new GHG model was then used to analyze the impact of climate change and extreme weather conditions on the denitrification rate, N2O emissions, and nutrient cycling/export in the 7.4 km2 WE38 watershed in Pennsylvania. Climate change impacts hydrology and nutrient cycling by changing soil moisture, stoichiometric nutrient ratios, and soil temperature, potentially complicating mitigation measures. To quantify the impact of climate change we forced the new GHG model with downscaled and bias-corrected regional climate model output and derived climate anomalies to assess their impact on hydrology, nitrate (NO3-), phosphorus (P), and sediment export, and on emissions of N2O and N2. Model-average (± standard deviation) results indicate that climate change, through an increase in precipitation, will result in moderate increases in winter/spring flow (2.7±10.6 %) and NO3- export (3.0±7.3 %), substantial increases in dissolved P (DP, 8.8±19.8 %), total P (TP, 4.5±11.7 %), and sediment (17.9±14.2 %) export, and greater N2O (63.3±50.8 %) and N2 (17.6±20.7 %) emissions. Conversely, decreases in summer flow (-12.4±26.7 %) and the export of P (-11.4±27.4 %), TP (-7.9±24.5 %), sediment (-4.1±21.4 %), and NO3- (-12.2±31.4 %) are driven by greater evapotranspiration from increasing summer temperatures. Increases in N2O (20.1±29.3 %) and decreases in N2 (-13.0±14.6 %) are also predicted in the summer and driven by increases in soil moisture and temperature. In an effort to assess the impact of climate change at a regional level, the model was then scaled-up to the entire Susquehanna River basin and was used to evaluate if agricultural best management practices (BMPs) can offset the impact of climate change. Agricultural BMPs are increasingly and widely employed to reduce diffuse nutrient pollution. Climate change can complicate the development, implementation, and efficiency of BMPs by altering hydrology, nutrient cycling, and erosion. We select and evaluate four common BMPs (buffer strips, strip crop, no-till, and tile drainage) to test their response to climate change. We force the calibrated model with six downscaled global climate models (GCMs) for a historic period (1990-2014) and two future scenario periods (2041-2065) and (2075-2099) and quantify the impact of climate change on hydrology, NO3-, total N (TN), DP, TP, and sediment export with and without BMPs. We also tested prioritizing BMP installation on the 30% of agricultural lands that generate the most runoff (e.g., critical source areas-CSAs). Compared against the historical baseline and excluding the impact of BMPs, the ensemble model mean (± standard deviation?) predictions indicate that climate change results in annual increases in flow (4.5±7.3%), surface runoff (3.5±6.1%), sediment export (28.5±18.2%) and TN (9.5±5.1%), but decreases in NO3- (12±12.8%), DP (14±11.5%), and TP (2.5±7.4%) export. When agricultural BMPs are simulated most do not appreciably change the overall water balance; however, tile drainage and strip crop decrease surface runoff generation and the export of sediment, DP, and TP, while buffer strips reduced N export substantially. Installing BMPs on critical source areas (CSAs) results in nearly the same level of performance for most practices and most pollutants. These results suggest that climate change will influence the performance of BMPs and that targeting BMPs to CSAs can provide nearly the same level of water quality impact as more widespread adoption. Finally, recognizing that all of these model applications have considerable uncertainty associated with their predictions, we develop and employ a Bayesian multi-model ensemble to evaluate structural model prediction uncertainty. The reliability of watershed models in a management context depends largely on associated uncertainties. Our Objective is to quantify structural uncertainty for predictions of flow, sediment, TN, and TP predictions using three models: the SWAT-Variable Source Area model (SWAT-VSA), the standard SWAT model (SWAT-ST), and the Chesapeake Bay watershed model (CBP-model). We initialize each of the models using weather, soil, and land use data and analyze outputs of flow, sediment, TN, and TP for the Susquehanna River basin at the Conowingo Dam in Conowingo, Maryland. Using these three models we fit Bayesian Generalized Non - Linear Multilevel Models (BGMM) for flow, sediment, TN, and TP and obtain estimated outputs with 95% confidence intervals. We compare the BGMM results against the individual model results and straight model averaging (SMA) results using a split time period analysis (training period and testing period) to assess the BGMM in a predictive fashion. The BGMM provided better predictions of flow, sediment, TN, and TP compared to individual models and the SMA during the training period. However, during the testing period the BGMM was not always the best predictor; in fact, there was no clear best model during the testing period. Perhaps more importantly, the BGMM provides estimates of prediction uncertainty, which can enhance decision making and improve watershed management by providing a risk-based assessment of outcomes.<br>Ph. D.

This study assesses the effects of a changing climate and population growth on water resources by modeling groundwater supplies in the Tucson Active Management Area. The finite-difference flow model, Modflow, is used to incorporate agricultural, municipal, and industrial well pumping along with natural and artificial recharge. This study expands on a Modflow model created by the Arizona Department of Water Resources to determine the impacts from limited water supplies and increased demand (Mason and Bota, 2006). Groundwater conditions and pumping in the Upper Santa Cruz and Avra Valley sub-basins are modeled starting in the year 1940 and continue to 2009. The model predicts pumping and recharge for the period of 2010 to 2050. During this projection period, nine scenarios based on various climate and population conditions are evaluated. Climate impacts are reflected in the amount of recharge entering the groundwater system. Local and regional climate conditions are incorporated since a large portion of the Tucson water supply is provided by the Colorado River water delivered along the Central Arizona Project (CAP). A decrease of 10% to the mean natural flow in the Colorado River over the next 50 years is used to predict Colorado River flows and shortages. Additionally, a 20% streamflow reduction case and two scenarios that evaluate the local and regional shortages individually are presented. Operational rules for the deliveries of the CAP water during shortage conditions are utilized to represent the system. The percentage of population growth is varied around the current case, which is extrapolated from data provided by the Arizona Department of Water Resources. Water demand is based upon the initial population, annual population growth, and gallons per capita day, which is a measurement of water use per person. The three population scenarios are limited growth, current case, and high growth. Results indicate groundwater depletion conditions are the worst during the high growth/shortage scenarios and best for the limited growth scenario. The change in storage of the aquifer is greatly driven by the pumping, which is dependent on population. For the shortage condition, the decline in natural recharge has a much larger effect on the change in water storage compared to the artificial recharge reductions due to shortages of CAP water.

The energy-food-water nexus is of fundamental significance in the goal towards sustainable development. The Zambezi River Basin, situated in southern Africa, currently offers vast water resources for social and economic development for the eight riparian countries that constitute the watershed. Hydropower generation and agriculture are the main water users in the watershed with great potential of expansion, plus urban water supply materialise the largest consumers of this resource. Climate and social changes are pressuring natural resources availability which might show severe alterations due to enhances in the variability of precipitation patterns. This study thus examines the present water resources in the transboundary basin and executes low and high case future climate change incited scenarios in order to estimate the possible availability of water for the period 2060-2099 by performing water balances. Along with projections of water accessibility, approximations on water demands from the main consumer sectors are performed. Results show an annual positive balance for both projected scenarios due to an increase in precipitation during the wet season. They also present a severe increase in overall temperature for the region contributing to a strong increase in evapotranspiration. Projections further inform of an acute increase in water demand for irrigation and urban supply, nevertheless, evaporation from hydropower storage reservoirs continues to exceed water with drawals in volume. Acknowledging the uncertainty contained in this report allows a broader offer of recommendations to be considered when planning for future developments with a sustainable approach. Improvement of hydrological collection systems in the Zambezi basin is indispensable to accomplish a deeper and cohesive understanding of the watershed waterresources. Cooperation and knowledge communication between riparian countries seems to be the right beginning towards social and economic sustainable development for the Zambezi River Basin.

Water management in the Washington Metropolitan Area (WMA) is challenging because the system relies on flow in the Potomac river, which is largely uncontrolled and augmented by the Jennings-Randolph reservoir, located 9-10 days travel time upstream. Given this lag, release decisions must be made collectively by federal, state and local stakeholders amid significant uncertainty, well in advance of accurate weather forecasts with no ability to recapture excess releases. Adding to this uncertainty are predictions of more severe and sporadic rainfall over the next century, caused by anthropogenic climate change. This study aims to evaluate the potential impacts of demand and climate change on the WMA water supply system, identifying changes in system vulnerability over the next century and developing adaptation strategies designed to maximize efficiency in a nonstationary system. A daily stochastic streamflow generation model is presented, which succesfully replicates statistics of the historical streamflow record and can produce climate-adjusted daily time-series. Using these time series, a multi-objective evolutionary algorithm is used to optimize the system's operating rules given current and future conditions, considering several competing objectives.<br>Ph. D.

This is a thesis about water efficiency, a particular set of practices in the water industry of England and Wales designed to reduce end-use water demand in homes and businesses. Broadly, the thesis aims to understand how water efficiency activities organised and funded by water companies might more effectively support the development of sustainable patterns of domestic demand, in order to contribute to long-term sustainable water management. To achieve this aim, mixed qualitative methods are used to; a) evaluate the extent to which two non-conventional water efficiency activities engage with the collective elements of everyday consumption that existing research deems necessary to steer demand (Strengers, 2012, Macrorie et al., 2014, Shove, 2014, Geels et al., 2015); b) develop a conceptual understanding of demand management as a professional practice, to understand how Water Company activities are shaped, sustained and stifled; and c) develop an understanding of what future water efficiency activities might look like that take account of the findings from this research. Central to this research and analysis is the notion of 'collective', a term that denotes a conceptual perspective on demand that departs from a focus on individuals, towards the shared social, technological and natural relations that structure everyday activity (Browne et al., 2014). The analysis uses this notion of collectives to examine the impacts and limitations of Save Water Swindon, a large-scale 'whole-town' approach to water efficiency (Case Study 1); to explore how Care for the Kennet contributes to demand management by reconfiguring relations between water in the home and water in the river (Case Study 2); and to uncover the collective context of the professional practices of managing demand (Case Study 3). The findings illustrate that demand is shaped by routines that extend far beyond the spaces in which water is used, both intentionally and unintentionally, and therefore highlight a distributed web of people and practices that might be involved in demand management. The findings from these empirical enquiries are used to as the basis to work with the water industry to reimagine interventions that engage in the collective context of demand, and elicit conceptual understandings of the processes and actors involved in governing social change. Overall, the approach taken in this thesis demonstrates the vitality of practice-based enquiry that provides deep analytical detail to better understand the mundane yet complex processes that sustain everyday water use. Supplementing the analysis with ideas from a variety of social science disciplines and working alongside the water industry, facilitated by the CASE studentship, pushes the analysis beyond the confines of domestic practices typical of practice-based research. Subsequently this research offers contributions to policy, practice and theoretical developments as it explores the intersections between demand and professional practices and local environments, evaluates interventions, examines practices of demand management, and unravels the possibilities for future intervention. Consequently, though focused on water management in the UK, this research offers insights for other resource agendas and regional contexts, expanding discussions in these spaces to think creatively about avenues for future policy and management practice.

Frequent climatic shocks have presented challenges for rainfed agriculture in sub-Saharan Africa. Appropriate water management practices are among the solutions to the challenges. The role of water harvesting in achieving sustainable agricultural intensification and specified resilience was explored. Suitable areas for water harvesting in the Upper Blue Nile basin were identified. The usefulness of the Curve Number method for surface runoff estimation was evaluated, and was found to perform satisfactorily. The impact of climate change in the Lake Tana sub-basin was studied. A decision support system was developed for locating and sizing of water harvesting ponds in the SWAT model. Methodological developments enabled analysis of the implications of water harvesting intensification in a meso-scale watershed in the Lake Tana sub-basin. Results suggest that water harvesting can increase agricultural productivity, sustain ecosystems and build specified resilience, and thereby contribute to sustainable agricultural intensification. There is considerable potential for water harvesting in the Upper Blue Nile Basin. Rainfall may increase in the Lake Tana sub-basin due to climate change. Supplementary irrigation from water harvesting ponds and better nutrient application increased staple crop production by up to three-fold. Moreover, a substantial amount of cash crop was produced using dry seasonal irrigation. Water harvesting altered the streamflow regime, and reduced sediment loss from the watershed.       Water harvesting can play an important role in food security. It showed potential to buffer climatic variability. In the watershed studied, water harvesting will not compromise the environmental water requirements. Instead, increased low flows, and reduced flooding and sediment loss may benefit the social-ecological systems. The adverse effects of disturbance of the natural flow variability and sediment influx to certain riverine ecosystems warrant detailed investigation.<br><p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Manuscript. Paper 3: Manuscript. Paper 5: Epub ahead of print. Paper 6: Manuscript.</p><br>Water resources management and social-ecological resilience

La modélisation hydrologique est un moyen pratique de quantifier les réactions du débit des rivières au changement climatique et à la gestion humaine de l’environment et de l’eau. Cependant, il existe des incertitudes à la fois dans les entrées des modèle s(par exemple, les variables atmosphériques) et les modèles eux même(par exemple, les structures de modèle et les paramètres de modèle), qui peuvent affecter la précision du modèle et les conclusions. En se concentrant sur différentes sources d'incertitude, cette thèse passe en revue les études antérieures et propose de nouvelles approches pour estimer et comparer les incertitudes avec leurs applications concentrées sur la Chine. Cette thèse propose d’abord une approche tridimensionnelle de la partition de la variance qui estime l’incertitude des multiples produits de précipitation de types différents. La nouvelle estimation utilise des informations complètes dans les dimensions temporelle et spatiale et constitue donc un indicateur plus complet pour l'évaluation de l'incertitude, en particulier pour plusieurs jeux de données. Cette thèse propose ensuite un cadre ORCHIDEE-Budyko permettant d'attribuer le biais de décharge entre la simulation du modèle (fournie par le modèle de surface ORCHIDEE) et les observations aux sources d'incertitude des variables atmosphériques et de la structure du modèle. Le cadre qualifie la possibilité d'incertitudes différentes avec l'hypothèse de Budyko basée sur des facteurs physiques et le soutien de littératures existante. Cette thèse passe enfin en revue les activités humaines et leur impact sur le débit des rivières en Chine, ainsi que les approches associées utilisées pour la quantification. L’impact humain qui a été quantifié par la différence entre le débit fluvial observé et celui qui a été naturalisé est ensuite comparé à des simulations multi-modèles conduites par différents forçages. Les résultats montrent que l’incertitude dans les variables atmosphériques (par exemple, les précipitations) est grande, en particulier pour les modèles de circulation générale (GCMs). L'incertitude des précipitations est très probablement supérieure à celle de l'incertitude du modèle. L'incertitude associée au débit modélisé avec différents forçages est supérieure à l'ampleur de l'impact humain pour la plupart des régions, en particulier dans le sud de la Chine, ce qui rend la la quantification de l'impact humain pour ces régions difficile. Cette compréhension des incertitudes dans le cycle naturel de l'eau et de la gestion que lui imposent les hommes est une condition préalable à toute tentative de modélisation des pressions anthropiques<br>Hydrological modeling is a practical means to quantify responses of river discharge to climate change and human management. However, there are uncertainties in both the model input (e.g., atmospheric variables) and the models (e.g., model structures and model parameters), that can affect the model accuracy and the conclusions. Focusing on different uncertainty sources, this thesis reviews the past studies and provides new approaches for estimating and comparing the uncertainties with their applications concentrated over China. This thesis first proposes a three-dimensional variance partitioning approach that estimates the uncertainty among multiple precipitation products with different types. The new estimation uses full information in temporal and spatial dimensions and thus is a more comprehensive metric for uncertainty assessment especially for multiple datasets. This thesis then proposes a ORCHIDEE-Budyko framework that helps attribute the discharge bias between model simulation (provided by land surface model ORCHIDEE) and observations to uncertainty sources of atmospheric variables and model structure. The framework qualifies the possibility of different uncertainties with physical-based Budyko hypothesis and support of related literatures. This thesis finally reviews the human activities and their impact on river discharge over China regions as well as the related approaches that used for the quantification. The human impact that quantified as the difference between observed river discharge and the naturalized ones is then compared with multi-model simulations driven by different forcing inputs. Results show that the uncertainty in atmospheric variables (e.g., precipitation) is large especially for General Circulation Models (GCMs). Precipitation uncertainty is very likely larger than that of the model uncertainty. The uncertainty in the modeled discharge with different forcing is larger than the magnitude of human impact for most of the regions especially in south China, which impedes the credibility of human impact quantification for those regions. This understanding of uncertainties in the natural water cycle and the management humans impose on it is a prerequisite before attempting to model the anthropogenic pressures

<p> This dissertation is a study of two water management systems and their respective potential for adaptive change. It compares the principles of traditional common-pool resource communities with the policies and practices of contemporary acequias and the Middle Rio Grande Conservancy District. A review of the biophysical environment and relevant water laws and institutions provides a historical and environmental perspective on how the two distinct systems evolved into their current forms. The respective systems' capacities to continue to function in their basic forms in the face of climate change are evaluated through the conceptual lenses of resilience theory and the adaptive change cycle. The severe and extended drought that New Mexico is experiencing is causing a sharpened focus on how to limit water use. Shortage sharing is a traditional practice in common-pool resource cultures, as are other measures to manage a limited and vital resource, including monitoring, sanctions, exclusion of free-riders, equity of use, and reliance on democratic institutions to ensure collective decisions. These principles and practices are present to varying degrees in both systems and provide solid bases upon which to innovate and adapt to new conditions. The challenge will be to mobilize the will to change sufficiently to adapt while honoring the cultural values represented in each system; in other words, to build resilience into the systems. Opportunities to do so are explored and evaluated for their potential positive effects and possible downsides</p>

Climate change is a global concern as it may affect many aspects of life, including water supply. A tool used to model climate change’s impacts is called a General Circulation Model (GCM). GCMs project future scenarios including temperature and precipitation, but these are designed at a coarse resolution and require downscaling for employment for regional hydrologic modeling. There is a vast amount of research on downscaling and bias-correcting GCMs data, but it is unknown whether these techniques alter precipitation signals embedded in these models or reproduce climate states that are viable for water resource planning and management. Using the Tampa, Florida region for the case study, the first part of the research investigated 1) whether GCM and the downscaled, bias-corrected data were able to replicate important historical climate states; and 2) if climate state and/or transition probabilities in raw GCMs were preserved or lost in translation in the corrected downscaled data. This has an important implication in understanding the limitations of bias-correction methods and shortcomings of future projection scenarios. Results showed that the GCM, and downscaled and bias-corrected data did a poor job in capturing historical climate states for wet or dry states as well as the variability in precipitation including some extremes associated with El Niño events. Additionally, the corrected products ended up creating different cycles compared to the original GCMs. Since the corrected products did not preserve GCMs historical transition probabilities, more than likely similar types of deviations will occur for “future” predictions and therefore another correction could be applied if desired to reproduce the degree of spatial persistence of atmospheric features and climatic states that are hydrologically important. Furthermore, understanding the sustainability of water supply systems in a changing climate is required for undertaking adaptation measures. Many water suppliers employ GCMs to examine climate change’s effect on hydrologic variables such as precipitation, but little is known on the propagation of mismatch errors in downscaled products through cascade of hydrologic and systems models. The second study examined how deviations in downscaled GCMs precipitation propagated into streamflow and reservoir simulation models by using key performance metrics. Findings exhibited that simulations better reproduced the resilience metric, but failed to capture reliability, vulnerability and sustainability metrics. Discrepancies were attributed to multiple factors including variances in GCMs precipitation and streamflow cumulative distribution functions, and divergences in serial correlation and system memory. Finally, the last study examined multiple models, emission scenarios and an ensemble to obtain a range of possible implications on reservation operations for time periods 2030-2053, 2054-2077 and 2077-2100 since the future emission trajectory is uncertain. Currently there are four Representative Concentration Pathways (RCPs) as defined by the IPCC’s fifth Assessment Report which provides time-dependent projections based on different forecasted greenhouse gas emission and land use changes. For this research Representative Concentration Pathways (RCPs) 4.0, 6.0 and 8.5 were examined. Scenarios were evaluated utilizing reliability, resilience, vulnerability and sustainability performance metrics and compared to a historical baseline. Findings exhibited that RCP 4.5, the lower end of emission scenario, improved reservoir reliability and resilience over time. Conversely, RCP 8.5, highest emissions, resulted in a steady decline of all metrics by 2100. Although vulnerability increased by 2100 for all emission scenarios, on average RCP 4.5 was less vulnerable. Investigation of permits and adjustments to capture extreme flows might be necessary to combat climate changes and precipitation inputs along with improvements to atmospheric emissions, which correlated with system recuperation with time.

Doctor of Philosophy<br>Department of Biological & Agricultural Engineering<br>Stacy L. Hutchinson<br>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.

Doctor of Philosophy<br>Department of Agricultural Economics<br>Jeffrey M. Peterson<br>Water scarcity is already a critical issue in many regions across the world and in many places water supplies are likely to be further threatened by climate change (Bates et al., 2008). Climate change will affect water availability in these areas both directly and indirectly. The direct effects come about because increased temperature (accompanied by changes in wind, humidity, and solar radiation) may increase evaporative losses from surface water bodies, and also because reduced precipitation lowers the rate of water inflows. In the case of groundwater, these factors will reduce the rate of aquifer recharge (Bates et al., 2008). The indirect effects arise from the biophysical impacts of climate change on vegetation, which are induced from rising temperatures, changing precipitation regimes, and increased atmospheric carbon dioxide levels. As a result of climate change, significant changes are expected in the hydrological cycle. This research is focused in how climate change can affect crop, land, and water allocation over time. The specific issue of this research comes from the following question: Is climate change likely to have a significant impact on the effectiveness of different water conservation policies in the High Plains aquifer region? This study is focused on the American High Plains, one of the most important water-scarce agricultural regions in North America. The study region for this research is a 31-county area overlying the Ogallala aquifer in western Kansas. This region encompasses approximately the western third of Kansas. Across these counties, the estimated remaining usable lifetime for aquifer water ranges from 50 to over 200 years (KGS), representing the range of water available in various parts of the aquifer. A Positive Mathematical Programming (PMP) model (Howitt, 1995) was developed and calibrated to land- and water-use data in the thirty one county area for a base period of 2000-2008. The PMP simulation uses inputs of price conditions and the aquifer level in a given year to predict the acreages planted to each of the major crops and the water use by crop. Decision makers are assumed to maximize profits, given the limited availability of water and arable land. The major crops in the model include wheat, corn, sorghum, soybeans, and alfalfa; the vast majority of historical planted acreage in the case counties is comprised of these five crops. The model was run for each of the case regions after calibrating the PMP model to data from 2000-2008. Calibration ensures that the model predictions fall within a small tolerance of the base period observations. This step avoids the problem of over-specialization (where the model places all of the acreages under one or two of the most profitable crops), and gives realistic acres and water use figures with which to work. The results suggest that the effects of the use of water conservation policies such as water use restriction and permanent conversion to dryland crops have positive effects on the trends of the different variables studied. With the implementation of these two policies, lower levels of total water use and higher levels of saturated thickness result but with a consequence of lower levels of net returns. However, the positive effects are lower in almost all cases if the effects of climate change on the same policies are taken into consideration. The scenarios of higher levels of temperature and lower precipitation levels projected for the region imply a greater demand for water for irrigated crops that results in lower levels of saturated thickness and simultaneously lower levels of net returns.

Studies of climate change impacts on water resources show that some regions may experience negative impacts and additional strain on the ability to meet future demand. However, few practitioners have incorporated climate change into their water planning initiatives. To do so practitioners must first recognize climate change as a concern, acquire climate impacts information specific to their issues and scales, and then assess the potential impacts and adaptation options within the context of the system. Participatory modeling, in which stakeholders are actively involved in the construction of a computer model, is an effective method for accomplishing these tasks. The collaborative process fosters a shared learning experience and the model helps assess future conditions and policies. A year-long participatory modeling exercise was conducted in the Okanagan Basin in south-central British Columbia, Canada. The region's arid, snowmelt-dominated hydrology combined with recent rapid development make its water resources susceptible to climate change impacts. Participants, including water-related professionals, researchers, and representatives of non-governmental organizations, assisted in all stages of model development, from goal setting and issues identification to model calibration and testing. The completed model, constructed in STELLA™, conducts thirty-year monthly simulations of water supply and agricultural, residential, and conservation flow demands for a historic period and for the 2020's and the 2050's, using statistically downscaled climate information from the Hadley, CGCM2, and CSIRO general circulation models. The model suggests that climatic changes could impact the system more severely than population growth. Current projections show reduced ability of the system to meet demand, particularly during the dry month of August, when demand peaks. Adaptation strategies could play a role in maintaining system reliability. Participants found both the process and the resulting model valuable. They found the model to be a relevant and legitimate tool for exploring long-term water management in the Okanagan when used with the appropriate audience and with minor refinements. The model could support further dialogue with the Okanagan community to determine appropriate management options. This methodology is not limited to this case study, but is well-suited for other applications of resource management, policy development, collaborative learning and negotiation.<br>Science, Faculty of<br>Resources, Environment and Sustainability (IRES), Institute for<br>Graduate

This research examines the application of a Classic Glaserian Grounded Theory methodology to the phenomenon of drought when viewed from the perspective of household water users in southern England. The resulting conceptual work calls into question the effectiveness of water-wise messaging and current Government policies on water management, by highlighting the double assurances afforded to the public through their own observations of the natural cycling of water resources between atmosphere and land, and the continuous operation of the regulated water industry, that together sustain blind belief in the ongoing availability of potable water resources. To establish a clear separation between the development of substantive theory and mixed method studies that claim to take a grounded theory approach that are generally more popular within the discipline of Human Geography, the theory is presented alongside two pieces of work; a collection of modern drought histories and a questionnaire. Developed as part of the necessary process of cycling alternate projects to enable a theory to emerge from the data whilst the researcher is distracted from forcing her own ideas onto it, both these pieces can be viewed separately or as supportive companions to the theory. Additionally, in acknowledging the difficulty in presenting a Classic Grounded Theory in the traditional discussional form, for the benefit of the reader the theory is preceded by an autoethnography, which incorporates descriptive elements taken from field notes and the author’s personal water diary. These works draw data from subjects in three counties in England (Norfolk, Kent, and Devon), following the northwest – southeast rainfall gradient. Supplementary material for the drought histories is drawn from local and national archives and recorded oral histories. The primary emphasis of this work is placed on assessing the merits of each of the methods deployed in addressing environmental social science issues in the context of climate change, which hitherto have been focused on perception questionnaires and the development of popular cultural typologies.

Stormwater runoff is one of the leading causes of water quality impairment in the U.S. Bioretention systems are ecologically engineered to treat stormwater pollution and offer exciting opportunities to provide local climate change resiliency by reducing peak runoff rates, and retaining/detaining storm volumes, yet implementation is outpacing our understanding of the underlying physical, biological, and chemical mechanisms involved in pollutant removal. Further, we do not know how performance will be affected by increases in precipitation, which are projected to occur in the northeastern U.S. as a result of climate change, or if these systems could act as a source or sink for greenhouse gas emissions. This research examines the design, construction, and development of monitoring methods for bioretention research, using the University of Vermont (UVM) Bioretention Laboratory as a case study. In addition, this research evaluates mobilization patterns and pollutant loads from road surfaces during the "first flush" of runoff, or the earlier part of a storm event. Finally, this research analyzes the comparative pollutant removal performance of bioretention systems on a treatment by treatment basis. At the UVM Bioretention Laboratory, eight lined bioretention cells were constructed with monitoring infrastructure installed at the entrance and at the subterranean effluent. A conventional, sand and compost based, bioretention soil media was compared to a proprietary media engineered to remove phosphorus, called Sorbtive Media™, under simulated increases in precipitation. Two drought tolerant vegetation mixes, native to the northeast, were compared for sediment and nutrient retention. Each treatment was sampled for soil gas emissions to determine if it was a source or a sink. The monitoring infrastructure designs used in this research allowed for the effective characterization of pollutant mass loads entering and exiting bioretention. Cumulative mass loads from stormwater were found to be highest for total suspended solids, followed by total Kjeldahl nitrogen, nitrate, non-labile phosphorus and soluble reactive phosphorus, in descending order by mass. Total suspended solids, total Kjeldahl nitrogen, and non-labile phosphorus mass were well retained by all bioretention treatments. However, the compost amendment in the conventional soil media was found to release labile nitrogen and phosphorus, far surpassing the mass loads in stormwater. When compared with conventional media, Sorbtive Media™ was highly effective at removing labile phosphorus and was also found to enhance nitrate removal. Systems containing deep-rooted vegetation (Panicum virgatum) were found to be particularly effective at retaining both labile and non-labile constituents. Overall, none of the bioretention treatments were found to be a significant source of N2O and were small sinks for CH4 in most treatments.

The purpose of this thesis is to examine the projected future changes in the global and Sub-Saharan Africa climate. These changes are expected to have varying effects depending on the region of the globe being examined. Sub-Saharan Africa is expected to be one of the most vulnerable regions in the future because of the already-variable and unpredictable climate. Population growth and lack of financial and informational resources further exacerbates the climate problems, making it even more difficult for African farmers to respond to their changing environment. In order to respond to these climate changes within an already dry and nutrient-lacking environment, farmers must be given the necessary adaptation information and aid from outside investors. However, without the proper information available to investors, regarding future expectations about precipitation, temperature, extreme weather events, soil nutrients, and available adaptation strategies, investors cannot efficiently allocate capital or other forms of aid. Therefore, I stress the importance of developing accurate climate models on a regional scale that investors can use to better allocate aid. Each region is affected in very different ways by the climate as a result of local topographical factors and global factors, such as the Intertropical Convergence Zone. Therefore, tools, such as models and simulations must be able to take these factors into account in order to accurately project future changes. This thesis examines a wide range of existing literature in the area of climate change and food security on both a global and regional scale. I investigate the current and future climate of Sub-Saharan Africa, as well as the farming culture, in order to provide an in-depth understanding of the various factors that are interacting. Although many steps have been made to develop models and provide aid to Sub-Saharan Africa farmers, the lack of food security is only expected to become worse as the environment becomes harsher on food crops. Therefore, in order to respond to the expanding population and harsher farming environment, farming adaptations must continue to be intensified.

<p> Dominica has been recognized for its landscape containing hundreds of rivers and receiving high rainfall, and "our water belongs to the world," or so says many Dominican citizens, and their government. A schism exists in the understanding of the water resources of Dominica. Local perceptions are in conflict with regional climate change data. Where climate change research has found Dominica to be high risk for water quality and quantity, locals maintain the mindset that there is an overabundance of the resource. Local epistemologies influence governmental water management practices, which presently focus on exportation of the resource. In efforts of economic development, while trusting that there is a surplus of water, Dominica leases billions of gallons of water each year to foreign companies. A popular conception on the island is that there is an abundance of water, and therefore, it should be shared globally. This unique social construction of Dominican water has been a foundation leading to the sale of billions of gallons of fresh water to international corporations. However, the bulk exportation of water is occurring in the context of climate change, and thus, the availability of water will be impacted by changes in annual rainfall, sea level rise, increased temperatures, and more severe hurricanes. The purpose of this study is to gain a better understanding of how the social understanding of water in Dominica was constructed, and what this means in relation to resource exportation and climate change. This research-based paper explores Dominican perceptions of water abundance and sustainability.</p>

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.

The energy consumption and greenhouse gas (GHG) emissions associated with urban water systems have come under scrutiny in recent times, as a result of increasing interest in climate change, to which urban water systems are particularly vulnerable. The approach most commonly taken previously to modelling these results has been to consider various urban water system components in great detail, but in isolation from the rest of the system. This piecewise approach is suboptimal, since it systematically fails to reveal the relative importance of the energy consumption and GHG emissions associated with each system component in the context of the entire urban water system. Hence, it was determined that a new approach to modelling the energy consumption and GHG emissions associated with urban water systems was necessary. It was further determined that the value derived from such a model would be greatly enhanced if it could also model the water consumption and wastewater generation associated with each system component, such that integrated policies could be developed, aimed at minimising water consumption, wastewater generation, energy consumption and GHG emissions concurrently. Hence, the following research question was posed: How should the relationships between the water consumption, wastewater generation, energy consumption and GHG emissions associated with the operation of urban water systems be modelled such that the impact of various changes to the system configuration made at different spatial scales can be determined within the context of the entire system? In this research project, life cycle assessment ideas were employed to develop such a new modelling methodology. Initially, the approach was developed at the building-scale, such that the end uses of water present in a selected building and any associated appliances could be modelled, along with the fraction of the citywide water supply and wastewater systems directly associated with providing services to that building. This vast breadth of scope was delivered by considering only the operational life cycle stage of each urban water system component, excluding both the pre- and post-operational life cycle stages of the associated infrastructure. The value of this pilot model was illustrated by several case studies, focused on residential buildings connected to the centralised water supply and wastewater systems in Melbourne, Australia. Later, the approach was extended to the city-scale by using probabilistic distributions of each input parameter, such that all of the end uses of water present in a city, and all of the associated building-scale appliances could be modelled, along with the associated complete water supply and wastewater systems. The value of this city-scale model was illustrated by applying it to model a hypothetical case study city, resembling Melbourne, Australia in many ways. Due to a lack of data, this application was limited to the residential sector of the case study city, along with the fraction of the citywide water supply and wastewater systems directly associated with providing services to that sector. The results generated by the pilot and city-scale models showed that the new modelling methodology could be employed at a wide range of scales to assess the relative importance of each modelled urban water system component in terms of the specified results. Importantly, the high resolution of those results enabled the identification of the underlying causes of the relative importance of each urban water system component, such that efficient and effective approaches to reducing each result for each system component could be developed. Interestingly, for the specific case studies investigated, it was revealed that some commonly neglected system components were actually extremely important, such as domestic hot water services, a trend found to be largely driven by hot water consumption in showers.

[EN] First chapter uses California's drought to identify the economic threats of water scarcity on food, energy and environmental systems as a way to introduce the multiple interactions between these resources. The second part of this first chapter introduces the focus of the dissertation, the water-energy nexus, presents a literature review identifying gaps, states the main and specific research objectives and the research questions, explains the research approach, and describes the organization of the dissertation. Second chapter develops an end-use model for water use and related energy and carbon footprint using probability distributions for parameters affecting water consumption in 10 local water utilities in California. Statewide single-family water-related CO2 emissions are 2% of overall per capita emissions, and locally variability is presented. The impact of several common conservation strategies on household water and energy use are assessed simulating different scenarios. Based on the this model, Chapter 3 introduces a probabilistic two-stage optimization model considering technical and behavioral decision variables to obtain the most eco-nomical strategies to minimize household water and water-related energy bills and costs given both water and energy price shocks. Results can provide an upper bound of household savings for customers with well-behaved preferences, and show greater adoption rates to reduce energy intensive appliances when energy is accounted, result-ing in an overall 24% reduction in indoor water use that represents a 30 percent reduc-tion in water-related energy use and a 53 percent reduction in household water-related CO2 emissions. To complete the urban water cycle, Chapter 4 develops first an hourly model of urban water uses by customer category including water-related energy consumption and next I calibrate a model of the energy used in water supply, treatment, pumping and wastewater treatment by the utility, using real data from East Bay Municipal Utility District in California. Hourly costs of energy for the water and energy utilities are assessed and GHG emissions for the entire water cycle estimated. Results show that water end-uses account for almost 95% of all water-related energy use, but the 5% managed by the utility is still worth over $12 million annually. Several simulations analyze the potential benefits for water demand management actions. The total carbon footprint per capita of the urban water cycle is 405 kg CO2/year representing 4.4% of the total GHG emissions per capita in California. Accounting for the results obtained in Chapters 2 to 4, Chapter 5 describes a simple but powerful decision support system for water management that includes water-related energy use and GHG emissions not solely from the water operations, but also from final water end uses, including demands from cities, agriculture, environment and the energy sector. The DSS combines a surface water management model with a simple groundwater model, accounting for their interrelationships, and also includes explicitly economic data to optimize water use across sectors during shortages and calculate return flows from different uses. Capabilities of the DSS are demonstrated on a case study over California's intertied water system over the historic period and some simulations are run to highlight water and energy tradeoffs. Results show that urban end uses account for most GHG emissions of the entire water cycle, but large water conveyance produces significant peaks over the summer season. The carbon footprint of the entire water cycle during this period, according to the model, was 21.43 millions of tons of CO2/year, what was roughly 5% of California's total GHG emissions. The last two chapters discus and summarize the thematic and methodological contribu-tions and looks for further research presenting and discussing the research gaps and research questions that this dissertation left open.<br>[ES] El primer capítulo utiliza la sequía de California para identificar las amenazas económicas de la escasez de agua en los sistemas de producción de alimentos, energético y medioambiental para presentar las múltiples interacciones entre estos recursos. La segunda parte del primer capítulo centra el objetivo de la tesis, la relación entre el agua y la energía, presenta la revisión de la literatura identificando los vacíos, describe los objetivos y las cuestiones que busca responder esta investigación, explica la metodología seguida, y describe la organización de la tesis. En el segundo capítulo se desarrolla un modelo de usos finales de agua, contando con la energía y las emisiones de GEI asociados utilizando distribuciones de probabilidad para los parámetros que afectan al uso del agua en 10 ciudades en California. Como resultados principales se obtiene que las emisiones de GEI asociadas al consumo residencial de agua representan el 2% del total de emisiones per cápita, y se presenta la variabilidad debida a las condiciones locales. Los impactos de algunas prácticas comunes de ahorro de agua y energía son calculadas simulando diferente escenarios. Basado en ese modelo, el Capítulo 3 se presenta un modelo de optimización probabilísticos en dos periodos considerando variables de decisión de modificaciones técnicas y de comportamiento en relación al consumo de agua para obtener las estrategias más económicas para minimizar las facturas de agua y energía. Los resultados proporcionan un límite superior para el ahorro doméstico, y muestran mayores tasas de adopción para reducir usos de agua que son más intensivos en consumo energético cuando la energía se incluye, resultando en una reducción del 24% de uso de agua adentro de las casas, que representa un 30% en reducción de energía y un 53% de emisiones de GEI, ambos relacionados con el consumo de agua. Para completar el ciclo urbano del agua, el Capítulo 4 desarrolla primero un modelo horario de usos de agua incluyendo la energía asociada y después se calibra un modelo de agua y energía en el abastecimiento, tratamiento y bombeo de agua, y el tratamiento de agua residual, utilizando datos reales de East Bay Municipal Utility District en California. Los costes horarios de energía para las compañías de agua y energía, así como las emisiones de GEI son estimadas. Los resultados muestran que los usos finales son responsables del 95% de la energía relacionada con el uso del agua, pero que el 5% restante tiene un coste de 12 millones de dólares anualmente. Teniendo en cuenta los resultados obtenidos en los capítulos 2, 3 y 4, el Capítulo 5 describe un sistema de apoyo de decisión (SSD) para gestión de recursos hídricos incluyente energía y emisiones de GEI no sólo de la gestión del agua, sino también de usos finales del agua, incluyendo demandas urbanas, agrícolas, ambientales y del sector energético. El SSD combina un modelo de agua superficial con uno de agua subterráneo, incluyendo sus interacciones, y también incluye explícitamente datos económicos para optimizar el uso del agua durante periodos de sequía. Las posibilidades del SSD son demostradas en un caso de estudio aplicado a un modelo simplificado del sistema de recursos hídricos de California. Los resultados muestran que los usos finales del agua en zonas urbanas son responsables de la mayoría de las emisiones de GEH, pero que las grandes infrastructures de transporte de agua producen importante picos en verano. De acuerdo con el modelo, la huella de carbón del ciclo del agua en California es de 21.43 millones de toneladas de CO2/año, lo que significa aproximadamente el 5% del total de emisiones de GEI del estado. Los últimos dos capítulos resumen y discuten las contribuciones temáticas y metodológicas de esta tesis, presentando nuevas líneas de investigación que se derivan de este trabajo.<br>[CAT] El primer capítol utilitza la sequera de Califòrnia per a identificar les amenaces econòmiques de l'escassesa d'aigua en els sistemes de producció d'aliments, energètic i mediambiental per a presentar les múltiples interaccions entre estos recursos. La segona part del primer capítol centra l'objectiu de la tesi, la relació entre l'aigua i l'energia, presenta la revisió de la literatura identificant els buits, descriu els objectius i les qüestions que busca respondre esta recerca, explica la metodologia seguida, i descriu la organització de la tesi. Al segon capítol es desenvolupa un model d'usos finals d'aigua, comptant amb l'energia i les emissions de GEH associats utilitzant distribucions de probabilitat per als paràmetres que afecten a l'ús de l'aigua en 10 ciutats en Califòrnia. Com a resultats principals s'obté que les emissions de GEH associades al consum residencial d'aigua representen el 2% del total d'emissions per càpita, i es presenta la variabilitat deguda a les condicions locals. Els impactes d'algunes pràctiques comunes d'estalvi d'aigua i energia són calculades simulant diferent escenaris. Basat en eixe model, al Capítol 3 es presenta un model d'optimització probabilístics en dos períodes considerant variables de decisió de modificacions tècniques i de comportament en relació al consum d'aigua per a obtindre les estratègies més econòmiques per a minimitzar les factures d'aigua i energia. Els resultats proporcionen un límit superior per a l'estalvi domèstic, i mostren majors taxes d'adopció per a reduir usos d'aigua que són més intensius en consum energètic quan l'energia es incluïda, resultant en una reducció del 24% d'ús d'aigua a dins de les cases, que representa un 30% en reducció d'energia i un 53% d'emissions de GEH, ambdós relacionats amb el consum d'aigua. Per a completar el cicle urbà de l'aigua, el Capítol 4 desenvolupa primer un model horari d'usos d'aigua incloent l'energia associada i després es calibra un model d'aigua i energia en l'abastiment, tractament i bombeig d'aigua i al tractament d'aigua residual, utilitzant dades reals de East Bay Municipal Utility District en Califòrnia. Els costs horaris d'energia per a les companyies d'aigua i energia, així com les emissions de GEH són estimades. Els resultats mostren que els usos finals són responsables del 95% de l'energia relacionada amb l'ús de l'aigua, però que el 5% restant té un cost de 12 milions de dolars anualment. Algunes simulacions analitzen els beneficis econòmics potencials de mesures de gestió de demanda d'aigua. La petjada de carbó total del cicle urbà de l'aigua s'estima en 405 kg CO2/any representant el 4.4% de les emissions per càpita en Califòrnia. Tenint en compte els resultats obtesos en els capítols 2, 3 i 4, el Capítol 5 descriu un sistema de suport de decisió (SSD) per a gestió de recursos hídrics incloent energia i emissions de GEH no sols de la gestió de l'aigua, sinó també del úsos finals de l'aigua, incloent demandes urbanes, agrícoles, ambientals i del sector energètic. El SSD combina un model d'aigua superficial amb un d'aigua subterrànea, incloent les seues interrelacions, i també inclou explícitament dades econòmiques per a optimitzar l'ús de l'aigua durant períodes de sequera. Les possibilitats del SSD són demostrades en un cas d'estudi aplicat a un model simplificat del sistema de recursos hídrics de Califòrnia. Els resultats mostren que els usos finals de l'aigua en zones urbanes són responsables de la majoria de les emissions de GEH, però que les grans infrastructures de transport d'aigua produïxen important pics a l'estiu. D'acord amb el model, la petjada de carbó del cicle de l'aigua a Califòrnia és de 21.43 milions de tones de CO2/any, el que significa aproximadament el 5% del total d'emissions de GEH a l'estat. Els últims dos capítols resumeixen i discuteixen les contribucions temàtiques i metodològiques d'esta tesi, presentan<br>Escrivà Bou, À. (2015). The Water-Energy Nexus: a bottom-up approach for basin-wide management [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/59451<br>TESIS<br>Premiado

The irrigated world area has been increased dramatically from the mid of 20th century. Freshwater use and its consumption have emerged as areas of high environmental concern. Although agricultural lands represent only 12% of the world’s land area, roughly 70% of water withdrawn from aquifers, streams and lakes are for irrigated agriculture. Climate change is a truly global problem around the world and the contribution from the agricultural sector is significantly high. Consequently, the environmental impacts from the use of water by agricultural activities and their relative contribution to Greenhouse Gas emissions should be properly addressed. The present thesis aims mainly to assess the environmental performance of different agricultural systems through the application of Life Cycle Assessment and other complementary methods. Two main environmental impacts were considered: Global Warming and Water Footprint. The objective is to provide farmers with methodological and practical decision- making tools to help them to practice in sustainable agriculture.<br>La superficie mundial de regadío ha aumentado drásticamente desde la segunda mitad del siglo XX. El uso de agua dulce y su consumo se han convertido en áreas de interés ambiental. Aunque las tierras agrícolas representan sólo el 12% de la superficie terrestre del mundo, aproximadamente el 70% del agua extraída de los acuíferos, ríos y lagos se utiliza para la agricultura de regadío. El cambio climático es un conocido problema global en todo el mundo y la contribución del sector agrícola es significativamente alta. Consiguientemente, los impactos ambientales procedentes del uso del agua debido a las actividades agrícolas y su relativa contribución en la emisión de Gases de Efecto Invernadero deben ser tratados adecuadamente. La presente tesis tiene como objetivo principal evaluar el perfil ambiental de los diferentes sistemas agrícolas a través de la aplicación del Análisis de Ciclo de Vida y otras herramientas complementarias. Principalmente, se consideraron dos impactos ambientales: el Calentamiento Global y la Huella Hídrica. El objetivo es proporcionar a los agricultores herramientas metodológicas y prácticas para la toma de decisiones y poder así practicar una agricultura sostenible.

Human impacts on the Chesapeake Bay through increased nutrient run-off as a result of land-use change, urbanization, and industrialization, have resulted in a degradation of water quality over the last half-century. These direct impacts, compounded with human-induced climate changes such as warming, rising sea-level, and changes in precipitation, have elevated the conversation surrounding the future of water quality in the Bay. The overall goal of this dissertation project is to use a combination of models and data to better understand and quantify the impact of changes in nutrient loads and climate on water quality in the Chesapeake Bay. This research achieves that goal in three parts. First, a set of eight water quality models is used to establish a model mean and assess model skill. All models were found to exhibit similar skill in resolving dissolved oxygen concentrations as well as a number of dissolved oxygen-influencing variables (temperature, salinity, stratification, chlorophyll and nitrate) and the model mean exhibited the highest individual skill. The location of stratification within the water column was found to be a limiting factor in the models’ ability to adequately simulate habitat compression resulting from low-oxygen conditions. Second, two of the previous models underwent the regulatory Chesapeake Bay pollution diet mandated by the Environmental Protection Agency. Both models exhibited a similar relative improvement in dissolved oxygen concentrations as a result of the reduction of nutrients stipulated in the pollution diet. A Confidence Index was developed to identify the locations of the Bay where the models are in agreement and disagreement regarding the impacts of the pollution diet. The models were least certain in the deep part of the upper main stem of the Bay and the uncertainty primarily stemmed from the post-processing methodology. Finally, by projecting the impacts of climate change in 2050 on the Bay, the potential success of the pollution diet in light of future projections for air temperature, sea level, and precipitation was examined. While a changing climate will reduce the ability of the nutrient reduction to improve oxygen concentrations, that effect is trumped by the improvements in dissolved oxygen stemming from the pollution diet itself. However, climate change still has the potential to cause the current level of nutrient reduction to be inadequate. This is primarily due to the fact that low-oxygen conditions are predicted to start one week earlier, on average, in the future, with the primary changes resulting from the increase in temperature. Overall, this research lends an increased degree of confidence in the water quality modeling of the potential impact of the Chesapeake Bay pollution diet. This research also establishes the efficacy of utilizing a multiple model approach to examining projected changes in water quality while establishing that the pollution diet trumps the impact from climate change. This work will lead directly to advances in scientific understanding of the response of water quality, ecosystem health, and ecological resilience to the impacts of nutrient reduction and climate change.

Sub-Saharan Africa is today facing a big challenge regarding food deficiency and water scarcity due to climate change. One of these countries is Rwanda, a small landlocked country in the middle of Africa. Rwanda strongly depend on agriculture, both in the aspect of reducing poverty and hunger but also because their economy security depend on it. Because of increasingly fluctuating rainfalls their agriculture becomes more dependent on irrigation and the availability to water resources. To investigate how the climate change will affect the amount of water resources in the coming decades, this study is focusing on the watershed and marshland of Muvumba P8 in Nyagatare, Rwanda. A hydrological model was created, in a software called Soil and Water Assessment Tool (SWAT), with soil, land use and slope maps for the watershed. Calibrating the model was done with help of Climate Forecast System Reanalysis (CFSR) data and run for nine different climate model datasets. An uncertainty had to be taken into account regarding both the measured local data and the downloaded data. To be able to compare the amount of water resources and the irrigation requirements for the rice crop the farmers were growing on the marshland, the crop water requirements for rice was estimated with FAO’s program called CROPWAT. The irrigation system on the marshland allows a double cropping of rice every year and consist of a system depending on elevation differences to create natural fall. There was three reservoirs along the marshland but to limit the project, only the first reservoir was taken into account. This was complemented with existing data and field survey. Six out of nine climate models showed a decrease in median discharge over the coming 30 years compared to the CFSR historical median discharge. This means that less water in general will reach the outlet of the watershed in the years to come. At the same time all climate models indicate an increase in irrigation requirements for the rice crops. The seasons are probably going to change, a longer and drier season between June and August and a rainier season between September and November are projected.

Pour répondre à la demande de la population croissante, la production de riz doit être augmentée de 40% d’ici 2030. Cependant cette production émet des gaz à effet serre (GES), tel que le méthane (CH4), qui contribue au réchauffement climatique. Les stratégies de gestion, telles que le drainage des sols et la gestion durable des résidus, sont essentielles pour diminuer les émissions de GES des rizières, mais cela entrent souvent en conflit avec les pratiques de gestion des riziculteurs. L'objectif de ce projet était d'étudier le potentiel d'atténuation des GES par des pratiques de drainage et de gestion des résidus et par l’identification des opportunités et les contraintes auxquelles sont confrontés les petits exploitants dans la mise en œuvre des pratiques. Le projet a été élaboré en utilisant une approche interdisciplinaire incluant mésocosme en chambre climatique, des campagnes sur le terrain et une enquête après des agriculteurs au Vietnam. La première étude sur le mésocosme a été menée pour identifier l'impact du drainage en début et mi-saison sur les émissions de CH4 et de N2O par des sols amendés avec des résidus frais et compostés à différents niveaux de sol C (article I). La deuxième étude sur le mésocosme incluait des résidus de riz enrichis en 13C pour comprendre l'effet de la pré-plantation, d’un drainage précoce et à mi-saison sur la contribution des résidus C aux émissions de CH4 (article III). Des expériences de terrain ont été menées pendant deux saisons (printemps et été) pour documenter l'effet de la pré-plantation, du drainage en début et à mi-saison sur les émissions de CH4 et de N2O par des sols modifiés par l’apport de résidus dans deux systèmes de gestion d’eau: un système efficace de gestion de l'eau et un système de contrôle d'eau conventionnel (article II). Trente-cinq petits producteurs de riz ont été interviewés pour évaluer la diversité des pratiques de gestion des terres dans la région et comprendre leurs pratiques de culture, leurs défis et leurs contraintes à l'échelle de la rizière. Quatre ateliers ont été menés avec des agriculteurs, des conseillers agricoles locaux et régionaux pour concevoir et évaluer les pratiques de production de riz adaptées au climat, basées sur la gestion de l'eau et des résidus (article IV). Les études de laboratoire et de terrain ont montré que les pratiques de drainage (pré-plantation et drainage précoce) pouvaient atténuer les émissions de GES sans compromettre le rendement du riz. Au laboratoire, le drainage avant plantation a considérablement réduit les émissions de CH4 de 70 à 80%, alors que sur le terrain, le drainage se montre moins efficace dans la réduction des émissions de CH4 en raison des activités opérées par les agriculteurs avant transplantion. Dans l’étude de terrain, le drainage précoce et en mi-saison a diminué les émissions de CH4 de 67% et 43% dans les systèmes comprenant une gestion de l’eau efficaces et inefficaces. Au laboratoire, l’addition d’un drainage en début et mi-saison a réduit les émissions de CH4 de 75 à 90%. Sur le terrain, le système efficace de contrôle de l'eau associé avec une bonne aération des sols a considérablement augmenté le potentiel de diminution du CH4 des sols drainés et modifiés par les résidus. L'étude isotopique a indiqué que l'aération des sols au stade précoce (pré-plantation ou début de saison) réduit les émissions de CH4 dérivés des résidus de 57 à 87%. Cependant, les résultats ont mis en évidence que l’amélioration des pratiques de drainage impactaient très peu les émissions de N2O. Les résultats de l'étude participative ont souligné l'importance d'impliquer les agriculteurs et les acteurs locaux dans la conception des systèmes d'atténuation des GES. Ces résultats ont mis en évidence les contraintes et les opportunités possibles pour la mise en œuvre réussie des stratégies d'atténuation des GES dans les rizières des petits exploitants<br>Rice production needs to increase by 40% to meet the demand of the world’s growing population by 2030, yet rice production contribute to global warming with elevated GHG emissions, particularly of methane (CH4). Management strategies, such as drainage of paddy soils &amp; sustainable residue management are essential in order to mitigate GHG emission from rice systems, but they often conflict with the practical management preferences of rice farmers. The objective of this project was to investigate the GHG mitigation potential of drainage practices and residue management techniques, and to identify the constraints and opportunities faced by smallholders in the implementation of mitigation practices under local conditions. The project was formulated using an interdisciplinary approach that included two mesocosm studies in growth chamber, two field campaigns and a field survey of farmers in Vietnam. First mesocosm study was conducted to verify the impact of early season drainage and midseason drainage on CH4 and N2O emissions from fresh and composted residue-amended soils at different soil C levels (Paper I). Then second mesocosm study was conducted using 13C-enriched rice residue to understand the effect of pre-planting, early-season and midseason drainage on the residue carbon contribution to CH4 emissions (Paper III). Field experiments based on farmers’ field conditions were conducted for two seasons (spring and summer) to document the effect of pre-planting, early-season and midseason drainage on CH4 and N2O emissions from residue-amended soils under two field water management systems: an efficient field water control system and a conventional, inefficient field water control system (Paper II). Thirty-five smallholder rice farmers were interviewed to capture the diversity of different land management practices in the area and understand their cropping practices, challenges and constraints faced at field scale. Four workshops were conducted with farmers, local agricultural advisors and regional stakeholders to design and assess the climate-smart rice production practices, based on water and residue management (Paper IV). The lab and field studies showed that drainage practices (pre-planting and early season drainage) had the potential to mitigate GHG emissions without compromising rice yield. Pre-planting drainage greatly reduced CH4 emissions in the lab experiment by 70-80%, while in field condition pre-planting drainage had less effect on CH4 emission reduction due to constraints with farmers’ field operations before transplanting. Early season drainage reduced CH4 emissions in both lab and field experiments. In field study, early plus midseason drainage lowered the CH4 emissions by 67% and 43% in the efficient and inefficient field water management systems respectively. In lab, early plus midseason drainage lowered CH4 emissions by 75-90 %. The efficient field water control system and good soil aeration significantly increased the CH4 mitigation potential of the drainage regimes from residue-amended soils. The isotopic study in lab indicated that soil aeration in the early stage (pre-planting or early season) reduced the residue-derived CH4 emissions by 57-87%. The results highlighted that the effects of improved drainage practices on N2O emissions were very low when considering the total GHG effects of CH4 and N2O. The results of the participatory study highlighted the importance of involving farmers and local stakeholders in the process of designing the mitigating systems. The active involvement of farmers and local stakeholders in the process of designing, testing and assessing the water management systems highlighted the constraints and feasible options for successful implementation of GHG mitigation strategies in smallholders’ rice fields

Rainwater harvesting (RWH) in the UK has seen a low level of uptake relative to similar settings such as Australia and Germany. The relatively low cost of municipal water in the UK limits the financial savings associated with RWH systems, especially in a domestic setting. Although financial benefits can be relatively low (in terms of reduced water bills), academic and practitioner studies have demonstrated the potential for RWH to significantly reduce potable water demands at typical UK houses. Hence, increased uptake of RWH has potential to contribute to mitigating droughts in water scarce regions. Stormwater management in the UK is receiving increasing attention at all levels; from grass-roots sustainable drainage systems (SuDS) such as downpipe disconnections and raingardens; through to implementation of urban realm attenuation schemes and continued development of guidance from UK policy makers. The public realm nature of most SuDS presents a need for partnership approaches to be fostered between infrastructure mangers and the general public. The application of RWH as a technology within the SuDS management train has been limited in the UK as policy makers have taken the view that RWH tanks may be full at the start of a design storm, and thus the potential for attenuation and peak discharge reduction has been largely ignored. However, in the last few years there has been a shift in emphasis; from RWH perceived purely as a water demand management technology to a focus on its wider benefits e.g. mitigating surface water flooding through improved stormwater management. RWH systems examined in this thesis are now available which offer multiple benefits to both end-users and water service providers. The application of RWH in a dual purpose configuration (to displace potable water demands and control stormwater discharges) has seen increasing interest during the development of this thesis. However, the successful design of RWH as a stormwater management tool requires a series of calculations to be completed. To date, practitioners have frequently relied upon low-resolution heuristic methods which lead to a small range of configurations being deployed, with minimal demonstrable stormwater control benefits. In this thesis, full details of novel and traditional RWH technologies were identified and described. Empirical data was collected, both in laboratory conditions and at field sites, to identify the real world operating characteristics of a range of RWH configurations. Additionally a new time series evaluation methodology was developed to enable RWH systems to be designed and analysed. This method quantifies water demand benefits and also focusses on stormwater management metrics (i.e. largest annual discharge and total discharge volume per year). The method was developed to enable a range of RWH configurations to be evaluated at a given site. In addition, a decision support tool (RainWET) was developed and tested which enabled the methods to be deployed in real world settings. The application of the RainWET software allowed a UK-wide, time series analysis of RWH configurations to be completed and the holistic benefits of a range of dual purpose RWH systems to be analysed and described. Evidence from the UK study suggests that a traditional RWH installation (3000l storage, 300l/day demand and 60m2 roof) installed at a house in a water scarce region (London, SAAR 597mm) was able to fully mitigate stormwater overflows over a 20 year analysis whilst providing a mean water saving of 31,255l/annum. An equivalent system located in the wettest region studied (Truro, SAAR 1099mm) saw mean reductions in the largest annual storm of 62% (range 35-86%) whilst satisfying a mean rainwater demand of 50,912l/annum. The study concluded that suitably designed dual purpose RWH systems offered better stormwater management benefits than those designed without a stormwater control device. In addition, the integration of smart RWH controls were shown to maximise stormwater control benefits with little or no reduction in a system’s ability to satisfy non-potable water demands.