Thesis (Ph. D.)--University of California, San Diego, 1993. / Photocopy. Ann Arbor, Mich. : University Microfilms International, 1994. 21 cm. Includes bibliographical references (p. 577-592).

Thesis (Ph. D.)--University of California, San Diego, 2005. / Vita. Includes bibliographical references (leaves 296-314).

Thesis (Ph. D.)--University of Queensland, 2003. / Includes bibliographical references.

Thesis (doctoral)--Lund University, 2003.

Thesis (Ph. D. in Economics)--Vanderbilt University, Aug. 2007. / Title from title screen. Includes bibliographical references.

Water systems in the Sultanate of Oman are inevitably exposed to varied threats and hazards due to both natural and man-made hazards. Natural disasters, especially tropical cyclone Gonu in 2007, cause immense damage to water supply systems in Oman. At the same time water loss from leaks is a major operational problem. This research developed an integrated approach to identify and rank the risks to the water sources, transmission pipelines and distribution networks in Oman and suggests appropriate mitigation measures. The system resilience was evaluated and an emergency response plan for the water supplies developed. The methodology involved mining the data held by the water supply utility for risk and resilience determination and operational data to support calculations of non-revenue water. Risk factors were identified, ranked and scored at a stakeholder workshop and the operational information required was principally gathered from interviews. Finally, an emergency response plan was developed by evaluating the risk and resilience factors. The risk analysis and assessment used a Coarse Risk Analysis (CRA) approach and risk scores were generated using a simple risk matrix based on WHO recommendations. The likelihoods and consequences of a wide range of hazardous events were identified through a key workshop and subsequent questionnaires. The thesis proposes a method of translating the detailed risk evaluations into resilience scores through a methodology used in transportation networks. A water audit indicated that the percentage of NRW in Oman is greater than 35% which is similar to other Gulf countries but high internationally. The principal strategy for managing NRW used in the research was the AWWA water audit method which includes free to use software and was found to be easy to apply in Oman. The research showed that risks to the main desalination processes can be controlled but the risk due to feed water quality might remain high even after implementing mitigation measures because the intake is close to an oil port with a significant risk of oil contamination and algal blooms. The most severe risks to transmission mains were found to be associated with pipe rather than pump failure. The systems in Oman were found to be moderately resilient, the resilience of desalination plants reasonably high but the transmission mains and pumping stations are very vulnerable. The integrated strategy developed in this study has a wide applicability, particularly in the Gulf area, which may have risks from exceptional events and will be experiencing NRW. Other developing countries may also experience such risks but with different magnitudes and the risk evaluation tables could provide a useful format for further work.

Orientador: Paulo Vatavuk / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-26T05:26:13Z (GMT). No. of bitstreams: 1 SouzaJunior_JosedoCarmode_M.pdf: 6575151 bytes, checksum: ab067f578f53eb5139546f4f0f2c13e2 (MD5) Previous issue date: 2014 / Resumo: O volume global de perdas de água é significativo. Cada ano, mais de 32 bilhões de m3 de água tratada são perdidos por vazamentos em redes de distribuição. Tendo em vista a complexidade dos sistemas de abastecimento de água, a divisão em sistemas menores permite analisar individualmente cada componente do sistema e definir ações que proporcionem uma gestão mais adequada. O presente trabalho tem por objetivo apresentar as ferramentas para gestão de perdas de água através da utilização dos Distritos de Medição e Controle (DMC's), que são áreas menores e mais gerenciáveis e possibilitam um controle efetivo de pressões e vazões nas redes de distribuição, proporcionando a redução dos volumes de água perdidos. A metodologia de utilização dos DMC's é internacionalmente aceita como uma das melhores práticas para redução de perdas de água, entretanto, sua aplicação é relativamente recente no campo de redes de distribuição. As áreas de abrangência dos DMC's são definidas tomando-se por base parâmetros como número de ligações de água, requisitos de pressão mínima e máxima, nível atual de vazamentos, limites do sistema de abastecimento, como áreas de bombeamento e áreas de válvulas redutoras de pressão, ou limites definidos através de estudos que identificam locais estratégicos para implantação de medidores de vazão. Após a implantação dos DMC's é realizado o gerenciamento das perdas de água, através do monitoramento das pressões e vazões. Os efeitos positivos do gerenciamento das pressões são reais para diminuir as perdas de água através da redução de pressões. A medição de vazão em redes de distribuição é outro fator importante no controle de perdas de água, pois sua correta utilização tem influência direta nos índices de perdas, onde é possível identificar áreas com níveis elevados de vazamentos. O trabalho apresenta um estudo de caso da implantação de DMC's no município de Bragança Paulista, operado pela Companhia de Saneamento Básico do Estado de São Paulo ¿ SABESP, demonstrando as ferramentas utilizadas para o gerenciamento das pressões e vazões, e propõe uma metodologia para intensificar os trabalhos de redução de perdas em DMC's, através de um sistema de informações geográficas, indicadores de desempenho adotados pela International Water Association (IWA) e da elaboração do balanço hídrico com o software gratuito do Banco Mundial WB-EasyCalc. Os resultados demonstram que a ferramenta possibilita uma gestão efetiva, através de uma ação mais focada nos DMC's que apresentam os maiores índices de perdas de água. Palavras-chave: Distrito de Medição e Controle (DMC), Rede de Distribuição de Água, Perdas de Água / Abstract: The overall volume of water losses is considerable. Each year, more than 32 billion m3 of drinking water are lost through leakage in water distribution networks. Given the complexity of water supply systems, the division into smaller structures allows the analysis of individual components and define actions that provides better management. This study presents the tools for managing water losses using District Metered Areas (DMAs), which are smaller and more manageable areas and enable effective control of pressures and flows in water distribution networks, providing a reduction in the volume of water losses. The methodology of using DMAs is internationally accepted as one of the best practices for reducing water losses, however, it¿s application is relatively new in the field of water distribution networks. The areas covered by the DMAs are defined by taking into consideration parameters like number of connections, minimum and maximum pressure requirements, current leakage level, limits of the water supply system as pump areas, and pressure reducing valves areas, or boundaries defined by studies that identify strategic locations for deployment of flowmeters. After having established DMAs, management of water losses is performed supervising the pressures and flow rates. The pressure management result in positive effects reducing water losses through reduced pressures. The measurement of flow in water distribution networks is another important factor in water loss control, because it¿s proper use has a direct influence on loss rates, where can identify areas with high levels of leakage. This study presents a case study about implementation of DMAs in the city of Bragança Paulista, operated by the Water Sanitation & Company of the State of São Paulo - SABESP, showing the tools used to manage pressures and flow rates, and proposes a methodology to improve works about water losses reduction in DMAs, through a Geographic Information System, performance indicators used by the International Water Association (IWA) and the development with the free water balance software from the World Bank, WB EasyCalc. The results shows that the tool allows effective management of water losses through actions in DMAs wich have the highest water losses. Keywords: District Metered Area (DMA), Water Distribution Network (WDN), Water Loss / Mestrado / Recursos Hidricos, Energeticos e Ambientais / Mestre em Engenharia Civil

This research study addresses the problem of whether local government can afford free basic water in rural areas. To achieve this objective a comprehensive literature study was performed, which included: · Lessons in water sector approaches from international experience and how these experiences compare with the South African situation. 1.The current basic water supply legislation in South Africa and how this legislation affects the subsidy arrangements and the financing of free basic water. 2.The operation and maintenance cost and the benefits of effective operation and maintenance of water supply schemes. A model was developed that could estimate the cost of rural water supply per household per month from the operation and maintenance data that was collected over a period of twenty-two months from a water supply scheme. As part of the provision of free basic water, a nine-step flow chart was developed to determine rural water operation and maintenance subsidy and a free basic water policy to help local government make informed decisions. The model was tested on different water supply schemes to verify the accuracy of the models estimation of the cost of rural water supply per household per month. The information obtained from the literature and from the test of the model resulted in various recommendations and conclusions.

A conceptual end use model for residential water demand and return flow is presented in this thesis. The model requires a unique description of a single residential stand in terms of all its end-uses. The end-uses include toilet flushing, bathing and showering, garden watering, leaks, et cetera. Various parameters describe each of the end-uses. The model predicts five components relating to water demand and wastewater flow at a residence: indoor water demand, outdoor water demand, hot water demand, wastewater flow volume and concentration of solutes in the wastewater. Twelve monthly results are calculated, for each of the five components, to provide a typical seasonal pattern as well as an annual value. The large number of input parameters in an end-use model allows for powerful and detailed analysis. The parameters required to populate the model are discussed and guideline values are presented. The end-use model is used to conduct a sensitivity analysis of each independent parameter for each of the five individual model components. The elasticity and sensitivity is determined at a base point with respect to each parameter for all five results. A research significance index is also devised to integrate the elasticity and availability of data for each parameter. The result is a prioritised list of the most critical parameters for each of the five components, which are the ones that should receive the focus for future study and data recording. The parameters are combined to obtain a list of the overall most important parameters in the model for all components combined, and based on a combination of the elasticity-based rank and the sensitivity based rank. The five most important parameters are the household size, toilet flush frequency, toilet flush volume, the washing machine event frequency and the volume of leaks on a stand. The practical application of the model is illustrated. The researchers first apply the model to mimic a few commonly accepted characteristics of water demand. The effectiveness of some specific water demand management measures are evaluated by adjusting selected model parameters. The measures include xeriscaping, the installation of dual-flush toilets, low-flow showerheads, pool ownership and pool cover use. The model also enables practitioners to obtain an insight into the water use habits of homeowners. The model forms the basis for further research work in the field. Its relatively simple structure and realistic data requirement encourages its integration into existing commercially available software suites for water and sewer system analysis and -management in the civil engineering industry in South Africa, as well as abroad. / Prof. J. Haarhoff

Magister Philosophiae - MPhil / This thesis examined a pre-paid water metering pilot project which was implemented in Klipheuwel , Cape Town, South Africa in 2001. It was anticipated that the implementation of pre-paid water meters would help improve the management of water service delivery in the Cape Metropolitan Area. However, just four years after its implementation the project has collapsed. / South Africa