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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.
331

Evolution of water supply mechanisms to reflect changing values: a case study of the Massachusetts water management program

Currey, Gregory Wayne 14 August 2009 (has links)
Industrialization and urbanization have brought about localized demand and regional competition for water resources in parts of the eastern United States. Thus, some states have faced critical decisions concerning how to best manage their available water supplies. As fundamental public values have changed over time, public opinion concerning the way in which water supplies should be managed has changed as well, especially in recent years. Consequently, many eastern states have restructured the institutional mechanisms governing water supply management to reflect those changing values and opinions. Massachusetts is a prime example of a state where changes in publicly held values have caused a thorough restructuring of the institutional mechanisms governing water supply management. A case study examines developments that led to the current institutional mechanisms in Massachusetts. Special attention is given to the issues and values that shaped the State’s water supply policy, legislation, and regulatory programs. / Master of Science
332

A Microcosm-Based Investigation into Oxidized Nitrogen Removal in the Hypolimnetic Waters of the Occoquan Reservoir of Northern Virginia

Banchuen, Tawan 22 January 2003 (has links)
The CE-QUAL-W2 model has been selected as a tool for use in water quality management studies of the Occoquan Reservoir. In order for the model to achieve its best possible predictive capability, additional quantitative information on denitrification rates in the reservoir was required. A microcosm operating protocol was developed to obtain such information and also to enhance the understanding of complex nitrate-sediment-phosphorus interactions. The microcosm system developed was a biphasic system, consisting of a single continuous stirred tank reactor (CSTR), or a series of CSTRs containing representative sediment and water samples from the reservoir. The system was configured to simulate the bottom waters in the upper reaches of the reservoir during anoxic conditions. Nitrate concentrations in the microcosm system were monitored, and first-order denitrification-rate constants calculated to be used as an input to the reservoir water quality model CE-QUAL-W2. Other water chemistries were also monitored to investigate the nitrate effects on water quality. From the investigation results, it appears that the first-order denitrification-rate constant of the model should be set at 0.22 day-1 instead of the model default value. Nitrate was also observed to be removed by chemical and/or biologically mediated reduction by reduced forms of manganese. Once the nitrate was depleted, soluble manganese was released from the sediment first, followed by soluble iron. The release of phosphorus was not observed in this study after the depletion of nitrate, but nevertheless, was believed to occur. The absence of the release was attributed to phosphorus adsorption to the Plexiglas reactor walls. / Master of Science
333

A Template to Enhance Regional Water Supply Planning

Ieuter, Toby C. 14 October 2004 (has links)
Regional water supply planning can be performed in a variety of ways and the impetus behind the creation of a regional water supply plan is as diverse as the constituents the plan serves. Formal water supply planning has been occurring for the last fifty years and a review of recent literature suggests that trends in water supply planning are leading to regional, integrated planning. Integrated regional water supply planning includes aspects of land use, population growth, environmental impacts, and planning for water supply to meet the needs of a region. A water supply plan outlines the water goals of a region. The regional water supply planning process can be assisted through the use of planning instruments such as an integrated plan template and a regional plan comparison checklist. The primary function of this thesis is to offer tools to guide the water supply planning process. The purpose is to enhance water supply planning by providing a template for integrated regional water supply planning. This thesis provides the planner with three tools: 1) an integrated plan template; 2) a condensed template; and 3) a regional plan comparison checklist. The primary contribution, the integrated plan template, is the result of a list of common water supply plan elements drawn from the current body of knowledge that can serve as a guide to inform community learning about regional water supply planning and/or aid in the structure of new plans. / Master of Urban and Regional Planning
334

THE QUANTITATIVE FEATURES OF CHINA'S WATER RESOURCES: AN OVERVIEW

Changming, Liu 02 1900 (has links)
China has a long history of hydrological development. According to Chinese legends, famous projects of flood water diversion were developed by the Great Yu as early as the year two thousand B.C. The earliest hydrological record appeared in 256 B.C., when Mr. Lipin and his son constructed the Dujiangyan irrigation system in the upper reach of the Mingjiang River in Sichuan Province. At Baopingkao, the water intake point of the Dujiangyan irrigation system, a water staff gage was carved on a stone for the measurement of water levels. Although hydrological studies in China started early, hydrology and water resources as modern sciences have been developed only in the last several decades, particularly rapidly in the last 30 years. For instance, the number of hydrological stations has increased 45 times, from about 350 to more than 16,000. Of these, about 3300 stations also take flow velocity measurements. The average density of the hydrological stations is about one per 530 km2 and that of discharge measurement stations about one in 3,000 km2. These stations are highly concentrated in eastern China. The longest records of precipitation are maintained in the large cities in eastern China, including Beijing, Shanghai and Tianjing. Beijing has 140 years of precipitation records. The Hankao hydrological station on the Changjiang (Yangtze) River has the longest discharge record spanning 117 years (1865- 1982).
335

THE INFLUENCE OF NON-COLIFORM BACTERIAL POPULATIONS ON POTABLE WATER QUALITY IN SOUTHERN ARIZONA.

Hinnebusch, Bernard Joseph. January 1982 (has links)
No description available.
336

Pre-paid water metering: social experiences and lessons learned from Klipheuwel pilot project, South Africa.

Kumwenda, Moses January 2006 (has links)
<p>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.</p>
337

Application of pinch technology in an integrated pulp and paper mill.

Naylor, Gladys M. January 2003 (has links)
The objective of this investigation was to utilise water pinch analysis as a tool for the optimisation of fresh water use in an integrated pulp and paper mill. The investigation was carried out at Mondi Paper in Merebank, south of Durban. The pulp and paper manufacturing process is a large consumer of fresh water and minimising the amount of fresh water used in the processes is beneficial from both a cost and environmental point of view. There are examples of mills which have "closed" their water systems to the extent that fresh water make up is minimal and most of the water is recycled and reused in a closed loop. These examples provide guidance on the basis of proven methods for reducing water consumption in the pulp and paper industry and can be used as a reference for mills wishing to reduce water consumption by making use of tried and tested methods. This investigation sought to provide an alternative method to identifying potential savings in fresh water consumption by making use of water pinch analysis. This was done at Mondi Paper by analysing individual parts of the mill and then a larger section of the mill which included both pulp and paper production. Flow rates of water streams and fibre content in those streams were obtained from plant data, where available, and this data was used to produce.a mass balance using the Linnhoff-March software, Water Tracker. The balance produced using Water Tracker provided the missing flow and fibre content data and this data was used as the input for the Linnhoff-March software, Water Pinch , to perform the water pinch analysis. The results achieved when analysing the individual parts of the mill did not demonstrate potential for significant savings in fresh water consumption, however the analysis of the integrated section of the mill identified a potential reduction in fresh water. It was found that the application of a single contaminant analysis to the larger section of the mill identified a possible reduction in the freshwater requirement of 8.1% and a reduction in effluent generated of 5.4%. This is a savings of R1 548 593 per annum based on 2003 costs of fresh water and effluent disposal. This analysis was conducted using the most simplified representation possible to produce meaningful results in order to evaluate the effectiveness of water pinch analysis in optimising the fresh water consumption in an integrated pulp and paper mill. It is demonstrated that water pinch analysis is potentially a useful tool in determining the minimum fresh water requirement of a site. / Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.
338

Second-order scarcity in Ethiopia : a case study of Gojjam.

Tiruneh, Mehhiku. January 2008 (has links)
Abstract not available. / Thesis (M.A.)-University of KwaZulu-Natal, 2008.
339

Water as 'n bron van politiek konflik en samewerking: 'n vergelykende studie van die Midde-Ooste en Suider-Afrika

29 October 2008 (has links)
M.A. / The potential for conflict over water can one day become a reality. This so, especially when the world’s population is growing at a phenomenal rate. Regions that are vulnerable to this sort of conflict are semi-arid to arid in character. One can ask the question if conflict over water in these regions is possible. In examining the situation surrounding waterpolitics in two regions, and drawing comparisons, one can shed light on state’s interaction when it comes to the allocation of international water sources. The Middle East has vast experience in international water politics, while countries in Southern Africa seem to be still learning the game of international water politics. Using a framework for analysis, four case studies will be looked at. The Orange and Okavango Rivers are the subjects in Southern Africa where, it seems, cooperation on international water resources is the norm. The Tigris-Euphrates and the Jordan Rivers are considered in the case of the Middle East. Here a much higher level of conflict can be seen. The main reason for this difference in dealing with international water resources in the two regions seems to be the will (or lack thereof) among states to cooperate over water sources. In Southern Africa this will is evident, especially after 1994 when a new democratically elected government came to power in South Africa. In the Middle East, however, the region is still going about international politics in ways reminiscent of the Cold War. The theory of realism helps to explain the situation in this region, where mistrust plays a very big part in the interaction between states. Complex interdependence by contrast characterises the international political interaction between the states in the Southern African region. International and national water projects, in both regions, play a very big role in water politics. In both the regions there seem to be a number of these projects, that contributed to either conflict and/or cooperation between the states. In the Orange River it is the Lesotho Highlands Water Project, a cooperative endeavour between Lesotho and South Africa and in the Okavango Namibia’s Eastern National Water Carrier (ENWC). In the Tigris -Euphrates, Turkey’s Greater Anatolia Project, in the Tigris -Euphrates, is influencing the interaction between the three riparians, and the Jordan River had it’s share of projects in the past, and here Israel’s National Water Carrier had a role to play. / Prof. D.J. Geldenhuys Dr. M.M.E. Schoeman
340

A mathematical modelling approach towards efficient water distribution systems: a case study of Zomba - Malawi's water distribution network

Fodya, Charles January 2016 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, May 2016. / This thesis presents work on four problems identi ed in the Zomba Water Distribution Network. The research was carried out on the existing network infrastructure with the aim of improving e ciency by reducing Unaccounted-For Water (UFW). The rst challenge was to develop a demand model for the city based on its in uencing factors: daily and seasonal uctuations as well as population dynamics. The model was to capture demand patterns for short-term, medium-term to long-term time periods, thereby becoming an important input factor into decision making. The developed model may be employed to generate demand which can be input into the city's 10 year infrastructure expansion plan. The second problem was to explain why houses built too close to tanks are at risk of inconsistent water supply. It was found that the requirement of observing the tank elevations, helv, had been violated. As a result, the discontinued supplies occurred. Once the required tank elevation helv had been established, an extra increase in the elevation so as to accommodate a larger population was determined to be on the order of one centimeter. Third problem was to explain the continued mains pipe failures observed in the network. It was established that the main cause was the hammering e ects started through the process of manually closing ow control valves (FCVs) tted next to tanks. A possible remedy was to rather t the FCVs at joint nodes and not at the tanks. This was estimated to greatly reduce the hammering e ects, eventually turning them into minor head losses due to elbow bends. Finally, a structural approach to designing tanks that optimize the use of gravity is presented. This is an input into the infrastructure expansion planning of the city. Regardless of any design shapes they may take, tanks with height-radius, h=r, ratio of less than 1 exhibit diminished, as opposed to increased, height changes with demand changes. Such a property would ensure consistency in the pressure at the tank, allowing for delivery of the demanded load. / GR2016

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