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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Simultaneous minimisation of water and energy within a water and membrane network superstructure

Buabeng-Baidoo, Esther January 2016 (has links)
A dissertation submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science in Engineering, 2015 / The scarcity of water and strict environmental regulations have made sustainable engineering a prime concern in the process and manufacturing industries. Water minimisation involves the reduction of freshwater use and effluent discharge in chemical plants. This is achieved through water reuse, water recycle and water regeneration. Optimisation of the water network (WN) superstructure considers all possible interconnections between water sources, water sinks and regenerator units (membrane systems). In most published works, membrane systems have been represented using the “black-box” approach, which uses a simplified linear model to represent the membrane systems. This approach does not give an accurate representation of the energy consumption and associated costs of the membrane systems. The work presented in this dissertation therefore looks at the incorporation of a detailed reverse osmosis network (RON) superstructure within a water network superstructure in order to simultaneously minimise water, energy, operating and capital costs. The WN consists of water sources, water sinks and reverse osmosis (RO) units for the partial treatment of the contaminated water. An overall mixed-integer nonlinear programming (MINLP) framework is developed, that simultaneously evaluates both water recycle/reuse and regeneration reuse/recycle opportunities. The solution obtained from optimisation provides the optimal connections between various units in the network arrangement, size and number of RO units, booster pumps as well as energy recovery turbines. The work looks at four cases in order to highlight the importance of including a detailed regeneration network within the water network instead of the traditional “black-box’’ model. The importance of using a variable removal ratio in the model is also highlighted by applying the work to a literature case study, which leads to a 28% reduction in freshwater consumption and 80% reduction in wastewater generation. / GR2016
22

Towards an integrated and sustainable water resource monitoring framework in South Africa

Chabalala, Simphiwe January 2017 (has links)
A thesis submitted to the faculty of science, at the University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2017. / Water resource monitoring plays a pivotal role in a number of sectors such as determining sustainable abstraction and use of water, determining the feasibility of development projects in relation to water, and developing systematic strategies for efficient overall management of the water resources. It has been observed by a number of scholars and policy makers that through periodic monitoring of water resources, valuable data can be collected which can then provide information sufficient to determine trends and develop predictive models. It is only when sound and reliable data is available that informed decisions about sustainable and efficient use of water resources can be made. Despite the importance of water resource monitoring, many countries in Sub-Saharan Africa, particularly in South Africa, are not effectively and adequately monitoring the quantity and quality of water resources. Part of the reason for this state of affairs has been the absence of clearly defined roles, policies, strategies and responsibilities and a combination of these factors have resulted in significant fragmentations in the institutional structures mandated to manage water resources. Using expert sampling, interviews with key informants and other purposively chosen participants, revealed the challenges in the changing political landscape of South African water resource monitoring many of which were further reiterated in the focus group discussions. The identified challenges served as entry points that would improve water resources monitoring and enable decision makers to make sustainable management decisions. It is suggested that water resource monitoring programmes could be used as a tool for sustainable water resource monitoring in South Africa. However, climate change and urbanization bring about a certain level of complexity, uncertainty and conflict as the water landscape of water resources changes continuously. The impact of the above phenomena cannot be measured as current monitoring systems are not functioning optimally. Furthermore, monitoring programmes are not being used to their full potential due to governance challenges. This is due to conflicting roles that the Department of Water and Sanitation (DWS) plays in the water sector i.e. policy developer, supporter and regulator, which in turn confound the roles and responsibilities of its employees. Moreover, it was found that five major challenges impede the formation of a comprehensive water resources management system namely; lack of financial resources, lack of skilled human resources, poor governance structure, ineffective stakeholder engagement – ‘working in silos’ and inefficient data management. More importantly, it was found that sustainability of monitoring programmes relies on human and economic investment. The main recommendations made include institutional reform and enabling legislation which form the basis upon which any development efforts can be pursued to achieve sustainable water resource monitoring. In addition, capacity building and strengthening is recommended as another way to help build sustainable resource management institutions which include skills and institutional memory transfer from the experienced players to the younger and newer employees. The creation and/or optimization of water resource monitoring databases is one of the viable ways for sustainable water resource management to be realized. Furthermore, research can be conducted to assess the challenges in water resource monitoring and provide sustainable solutions; with the aim of quantifying the impact of policy reforms in the water sector. And finally, research can be done on how effective regulation and co-operative governance for water sector can be achieved in South Africa through participatory processes that are aimed at developing priority water research questions. Keywords: water resource monitoring, institutional framework, integrated water resource management, water governance. / GR2018
23

From Diagnosis to Water Management: The role of Atmospheric Dynamics and Climate Variability on Hydrological Extremes

Lu, Mengqian January 2014 (has links)
The recent extreme hydrological extremes over the globe highlight the importance of understanding the role of atmospheric dynamics and climate variability on the occurrence of these extreme events and the associated temporal and spatial characteristics of sequences of the precipitation events. Most of the studies have been focusing on overall average impacts of long-term global climate change on extremes. Majority are driven largely by considering the changes of the moisture holding capacity as a function of temperature, as indicated by the Clausius-Clapeyron equation. Given the complex dynamical structure of the atmosphere, one needs to also consider the attendant atmospheric circulation and moisture transport mechanisms that lead to extreme precipitation and subsequent floods as evidenced in the recent major floods. This study first develops insights into the causative climatic factors associated with precipitation induced regional floods events and understand the roles of Atmospheric Rivers (AR) or Tropical Moisture Exports (TME) and atmospheric circulation patterns associated with the frequency and/or persistency of such events in the midlatitudes. The second part explores the spatiotemporal relationship between climate variability and global extreme precipitation occurrence using a graph based approach based upon the concept of reciprocity to investigated the linkages and influences of the slowly changing boundary conditions on the development or propagation of atmospheric circulations, to assess the predictability of global precipitation extremes given the leading modes of identified climate dipole networks. A multi-timescale statistical, climate informed, stochastic streamflow forecast model serves as the bridge linking the first two parts to the application in the third part: application on water resources management by developing a multi-timescale climate informed stochastic hybrid stimulation-optimization model for multi-purpose reservoir systems, which enables the utilization of the streamflow forecast. The novel reservoir operation model attempts to change the game of water resources management from its conservative, rigid rule-following scheme to a robust, market-based, reliable water allocation strategy. Part I. Tropical Moisture Exports, Extreme Precipitation and Major Flood Atmospheric Rivers are being increasingly identified as associated with some extreme floods. More generally, such floods may be associated with tropical moisture exports that exhibit relatively robust teleconnections between moisture source regions and flood regions. First, a large-scale flood event that persisted over Western Europe in January 1995 is studied. During the last ten days of the month, two rare flooding events, associated with heaviest rainfall in 150 years, occurred in two places, one over Brittany (West of France), and the second in the France-Germany border region and parts of neighboring countries. In this study, we explore the month-long evolution of tropical moisture exports (TME) and their connection to the precipitation events that led to the Brittany event. The persistent large-scale atmospheric circulation patterns that led to the birth, death and evolution of these TME as atmospheric rivers with landfalls in Western Europe are identified, and the relationship of daily extreme precipitation to these patterns is examined. Singular value decomposition (SVD) analysis and a generalized linear model (GLM) are used to assess whether knowledge of the atmospheric circulation patterns from the prior record is useful for explaining the occurrence of their rare events. The analysis establishes the importance of both global and regional atmospheric circulation modes for the occurrence of such persistent events and the hydrologic importance of diagnosing global atmospheric moisture pathways. Part II. Seasonal to Interannual Variability of Tropical Moisture Exports, Extremes and ENSO A statistically and physically based framework is put forward that investigates the relationship between Tropical Moisture Exports (TMEs), Extreme Precipitation and Floods. TMEs is the more general phenomena than Atmospheric Rivers (ARs) in terms of (1) facilitates the poleward transport of warm and moist air masses from low latitudes, primarily tropical oceanic areas, to higher latitudes; (2) contributes to the global climatology precipitation and its extremes; (3) closely relates to floods events, especially in the midlatitudes. The TMEs itself has seasonal and interannual variability that is regulated by slowly changing boundary conditions and climate variability, such El Niño Southern Oscillation (ENSO), while the trajectories and movements are presumably led by atmospheric circulations patterns driven by the balance of global energy and water budgets. In this study, we take Northwest US (NE US) to show how the TMEs is related to extreme precipitation and then floods, and the results of the variability of TMEs, coupled with atmospheric circulation patterns, on the extremes. Historical large floods events in NE US in different seasons are studied for their link to the TMEs. Major moisture sources of TMEs that contributes to precipitation, extremes and floods in NE US are identified, together with the sources' seasonally and interannually varying characterizes in terms of both birth and entrance to the NE US, with the consideration of large scale climate regulations and atmospheric circulation patterns. Part III. Correlation Networks for Identifying Predictors for Extended Range Forecasts for Extreme Precipitation Correlation networks identified from financial, genomic, ecological, epidemiological, social and climate data are being used to provide useful topological insights into the structure of high dimensional data. Strong convection over the oceans and the atmospheric moisture transport and flow convergence indicated by atmospheric pressure fields may determine where and when extreme precipitation occurs. Here, the spatiotemporal relationship between climate and extreme global precipitation is explored using a graph based approach that uses the concept of reciprocity to generate cluster pairs of locations with similar spatiotemporal patterns at any time lag. A global time-lagged relationship between pentad sea surface temperatures (SST) anomalies and pentad sea level pressure (SLP) anomalies is investigated to understand the linkages and influence of the slowly changing oceanic boundary conditions on the development of the global atmospheric circulation. We explore the use of this correlation network to predict extreme precipitation globally over the next 30 days, using a Principal Component logistic regression on the strong global dipoles found between SST and SLP. Unprecedented success of the predictive skill under cross validation for 30 days precipitation higher than the 90th percentile is indicated for selected global regions for each wet season considered. Part IV. Applications of Climate Informed Streamflow Forecasts for Water Management Streamflow forecasts at multiple time scales (e.g., season and year ahead) provide a new opportunity for reservoir management to address competing objectives. Market instruments such as forward contracts with specified reliability are considered as a tool that may help address the perceived risk associated with the use of such instruments in lieu of a traditional operation and allocation. A water allocation process that enables multiple contracts with different durations, to facilitate participatory management of the reservoir by users and system operators, is presented here. Since these contracts are based on a verifiable reliability they may in turn be insurable. A Multi-timescale climate informed Stochastic Hybrid Simulation - Optimization Model (McISH) is developed, featuring (1) dynamic flood control storage allocation at a specified risk level; (2) multiple duration energy/water contracts with user specified reliability and prices; and (3) contract sizing and updating to reflect changes in both demands and supplies. The model incorporates multi-timescale (annual and seasonal) streamflow forecasts, and addresses uncertainties across both timescales. The intended use is as part of an interaction between users and water operators to arrive at a set of short-term and long term contracts through disclosure of demand or needs and the value placed on reliability and contract duration. An application is considered using data for the Bhakra Dam, India. The issues of forecast skill and contract performance given a set of parameters are examined to illustrate the approach. Prospects for the application in a general setting are discussed.
24

Thirsty downstream : the provision of clean water in Jakarta, Indonesia

Argo, Teti Armiati 05 1900 (has links)
The challenge of water provision in third world cities is to maintain the supply in the context of inadequate and inefficient piped water infrastructure and diminishing raw resources. In order to examine the role of governance in this, I utilize a range of theoretical positions: the welfare orientation, rational choice paradigm, common goods theory and regime theory, and present them as ways to explore the subjective dimension of water provision. Using the city of Jakarta, Indonesia as a case study, this dissertation explores the issues using different perspectives on a single principal focus, the roles of the government and its relations to non-governmental actors. This research used data from secondary materials such as management reports, policy and academic reports, and scientific studies. The major source of primary data were interviews conducted with about 40 key actors. Qualitative analysis used a system of information coding and triangulation. The conclusion reached is that the approach to managing clean water provision needs to be redefined in relation to the water management regimes found in situated research. In Jakarta, one may define three regimes: piped water, surface and shallow groundwater, and deep groundwater. Accessing water from greater urban watershed, treatment plants and a "manufacturing process" results in the delivery of a product. Such a system reduces the possibility of the tragedy of the commons, that is, the over-extraction of groundwater by individuals. But a more inclusive and enforced regulatory system must be established for groundwater, as it remains a needed source of supply. Local and low-technology solutions, international agency assistance, the policies of privatization and decentralization, and better land use planning, all hold out the promise of movement towards a solution. But, as the case study demonstrates, success has so far been mixed. Many options do not address water scarcity at the city level and problems of inequitable service. It is only the prospect government reform towards a better allocation of roles, new management ideas and greater co-operation within and among the water regimes that will lead to better provision of clean water.
25

The Jordan River Basin : culture in resource management and conflict

Ritzler, Jacob January 2004 (has links)
This thesis is a case study of the impact of culture on the management of water resources and the conflict over their usage by opposing riparian entities in the Jordan River Basin. It provides an overview of the historical background to the resource conflict in the area and continues on to examine the development of management institutions. In particular, it examines the impact of Islamic law on the development of water laws and management, paying particular attention to the affect of Islamic law on water usage in Jordan and how in turn this affect is seen in its relations with neighboring states. Its purpose is to create an understanding, through cultural awareness, of the reasons behind the actions of particular states in reference to the cultural differences affecting their actions.
26

Regional groundwater monitoring in the Olifants-Doorn water management area.

Seward, Paul January 2006 (has links)
<p>The aim of this investigation was to provide a framework or strategy for prioritising and implementing regional groundwater monitoring in the Olifants-Doorn Water Management (WMA) area. The general approach was to attempt to reconcile monitoring requirements with existing resources, while investigating the hypothesis that regional monitoring should focus on resource status monitoring. Groundwater science needs to focus on clarifying the sustainability options available to the stakeholders, and monitoring the chosen option. This can best be done by adopting an adaptive management approach to both the management of the groundwater resources, and the management of the monitoring programme.</p>
27

Optimum water pricing and capacity expansion of water supply systems / by Michael Christopher Connarty.

Connarty, M. C. (Michael Christopher) January 1995 (has links)
Bibliography: leaves 414-427. / xx, 427 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Civil and Environmental Engineering, 1995?
28

Thirsty downstream : the provision of clean water in Jakarta, Indonesia

Argo, Teti Armiati 05 1900 (has links)
The challenge of water provision in third world cities is to maintain the supply in the context of inadequate and inefficient piped water infrastructure and diminishing raw resources. In order to examine the role of governance in this, I utilize a range of theoretical positions: the welfare orientation, rational choice paradigm, common goods theory and regime theory, and present them as ways to explore the subjective dimension of water provision. Using the city of Jakarta, Indonesia as a case study, this dissertation explores the issues using different perspectives on a single principal focus, the roles of the government and its relations to non-governmental actors. This research used data from secondary materials such as management reports, policy and academic reports, and scientific studies. The major source of primary data were interviews conducted with about 40 key actors. Qualitative analysis used a system of information coding and triangulation. The conclusion reached is that the approach to managing clean water provision needs to be redefined in relation to the water management regimes found in situated research. In Jakarta, one may define three regimes: piped water, surface and shallow groundwater, and deep groundwater. Accessing water from greater urban watershed, treatment plants and a "manufacturing process" results in the delivery of a product. Such a system reduces the possibility of the tragedy of the commons, that is, the over-extraction of groundwater by individuals. But a more inclusive and enforced regulatory system must be established for groundwater, as it remains a needed source of supply. Local and low-technology solutions, international agency assistance, the policies of privatization and decentralization, and better land use planning, all hold out the promise of movement towards a solution. But, as the case study demonstrates, success has so far been mixed. Many options do not address water scarcity at the city level and problems of inequitable service. It is only the prospect government reform towards a better allocation of roles, new management ideas and greater co-operation within and among the water regimes that will lead to better provision of clean water. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate
29

Factors that may compromise bulk water distribution reliability

Nel, Daniel Theodorus 05 June 2012 (has links)
D.Ing. / This thesis considers water supply and divides the water supply environment into three categories; the macro water supply environment, the water supply scheme and the consumers. Each of the categories is briefly explored in terms of the factors that may influence it. Subsequently, some of the unique features of a bulk water distribution system are dealt with, as well as different approaches related to bulk water distribution system design and assessment. One of these approaches, the probabilistic approach, offers unique features to assess the reliability of a bulk water distribution system but requires that the probabilistic characteristics of the stochastic events be quantified. The above prompted the goal of this thesis; “…to assess and quantify the probabilistic characteristics of selected factors that may compromise bulk water distribution reliability”. The objectives set and dealt with in this thesis are: • Conducting a literature review that explores uncertainty, reliability, models and techniques, highlighting selected factors that may compromise bulk water distribution reliability, as well as bulk water distribution system water requirements. • Quantifying the probabilistic characteristics of water distribution pipeline failures. • Quantifying the probabilistic characteristics of pipeline failures caused by sinkholes in dolomitic areas. • Quantifying the probabilistic characteristics of power supply failures. This study provides a comprehensive summary of a range of uncertainties that may compromise bulk water distribution reliability. However, the greatest value added corresponds to the following: • It establishes a benchmark related to the probabilistic characteristics of pipeline failures for five pipeline material categories, related to pipeline failure rates and pipeline repair times. • A new methodology is developed in terms of which the probabilistic characteristics of pipeline failures caused by sinkholes in dolomitic areas can be quantified. • It provides a benchmark of the probabilistic characteristics of power supply failures at bulk water distribution pump stations. Proposals are made related to future research needs, divided into two categories: • Complementary research needs that will complement and enhance the work undertaken within this thesis. • Promotional research needs that will promote the practical application of the outcomes generated as part of this thesis.
30

The applicability of microcomputers to local water management

Allen, Roderick Lee 01 January 1985 (has links)
Historically, hydrologic models have been available only on mainframe computers and have therefore not been used by local water managers to support daily decisions. The development of the microcomputer presents an opportunity for that to change. Mathematical models of soil moisture and river routing are selected, developed and tested for use on a microcomputer as an aid to local water management. The models are then integrated with an appropriate data base in a computer program written for a microcomputer. The result is a Decision Support System for local water managers. In order to evaluate the feasibility of using the Decision Support System, an application of the program to a small hypothetical river and irrigation system is carried out. The speed of execution indicates that the use of the Decision Support System on this class of computer under the present configuration may be possible if software or hardware changes can reduce data transfer times to and from disk.

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