Dissertations / Theses on the topic 'Water supply reliability'

Includes bibliographical references.
Bulk water supply systems are usually designed according to deterministic design guidelines. In South Africa, design guidelines specify that a bulk storage reservoir should have a storage capacity of 48 hours of annual average daily demand (AADD), and the feeder pipe a capacity of 1.5 times AADD (CSIR, 2000). Nel & Haarhoff (1996) proposed a stochastic analysis method that allowed the reliability of a reservoir to be estimated based on a Monte Carlo analysis of consumer demand, fire water demand and pipe failures. Van Zyl et al. (2008) developed this method further and proposed a design criterion of one failure in ten years under seasonal peak conditions. In this study, a method for the optimal design of bulk water supply systems is proposed with the design variables being the configuration of the feeder pipe system, the feeder pipe diameters (i.e. capacity), and the size of the bulk storage reservoir. The stochastic analysis method is applied to determine a trade-off curve between system cost and reliability, from which the designer can select a suitable solution. Optimisation of the bulk system was performed using the multi-objective genetic algorithm, NSGA-II. As Monte Carlo sampling can be computationally expensive, especially when large numbers of simulations are required in an optimisation exercise, a compression heuristic was implemented and refined to reduce the computational effort required of the stochastic simulation. Use of the compression heuristic instead of full Monte Carlo simulation in the reliability analysis achieved computational time savings of around 75% for the optimisation of a typical system. Application of the optimisation model showed that it was able to successfully produce a set of Pareto-optimal solutions ranging from low reliability, low cost solutions to high reliability, high cost solutions. The proposed method was first applied to a typical system, resulting in an optimal reservoir size of approximately 22 h AADD and feeder pipe capacity of 2 times AADD. This solution achieved 9% savings in total system cost compared to the South African design guidelines. In addition, the optimal solution proved to have better reliability that one designed according to South African guidelines. A sensitivity analysis demonstrated the effects of changing various system and stochastic parameters from typical to low and high values. The sensitivity results revealed that the length of the feeder pipe system has the greatest impact on both the cost and reliability of the bulk system. It was also found that a single feeder pipe is optimal in most cases, and that parallel feeder pipes are only optimal for short feeder pipe lengths. The optimisation model is capable of narrowing down the search region to a handful of possible design solutions, and can thus be used by the engineer as a tool to assist with the design of the final system.

The need of water and the limited sources, force the researchers to find the most economical and feasible solution in the design of a water distribution network. In this study, reliability and optimization of a water distribution network are taken into account together in the design stage of the network. The relationship between reliability of a water distribution network and its cost is examined during the design of a water distribution network. A methodology for deciding the reliability level of the selected design is proposed by examining the reliability-cost relationship. The design alternatives for the case study area are obtained by the aid of a commercially available software WADISO employing partial enumeration optimization technique. The reliability value for each of the design alternative is calculated according to Misirdali (2003)&rsquo
s adaptation based on the methodology proposed by Bao and Mays (1990) by the aid of a hydraulic network solver program HapMam prepared by Nohutç
u (2002). For purposes of illustration, the skeletonized form of Ankara Water Distribution Network subpressure zone (N8-1) is taken as the case study area. The methodology in this study, covering the relation between the reliability and the cost of a water distribution network and the proposed reliability level can be used in the design of new systems.

The optimal design of a bulk water supply system is centered on two major objectives: cost efficiency and the formation of a design solution that is appropriate for the conditions in which the system is to be implemented. The currently employed CSIR (2000) design guidelines utilise deterministic measures to size system components. The efficiency of following a deterministic approach to bulk water system design, involving pumping systems, was investigated. This was seen as necessary owing to the vast spectrum of influences and the interrelation of parameters that constitute a bulk water supply system. A model developed by Chang & van Zyl (2012) sought to address this inefficiency by optimizing a bulk water supply system, with the core objectives of cost and reliability. The determination of these objectives was achieved by using a capital cost model for cost determination and a stochastic model developed by Van Zyl et al. (2008) for reliability. While this produced workable results, the application was relatively limited, and applied only to non-pumped, gravity-fed flow. As such, the failure mechanisms of the supply system did not include the effects of pump failure, an important influence on overall system reliability. In addition, the costing system was based solely on capital cost and did not take into account the life-cycle cost involved with the implementation of a bulk water supply system. The investigation sought to expand the applicability of the model through the incorporation of pumping systems and life-cycle costing. It was further intended to compare the expanded model to both the model developed by Chang & van Zyl (2012) and the CSIR (2000) guidelines. A sensitivity analysis would also be performed.

Thesis (M.S.)--University of North Carolina at Chapel Hill, 2006.
Title from electronic title page (viewed Oct. 10, 2007). "... in partial fulfillment of the requirements for the degree of Master of Science in the Department of Environmental Sciences and Engineering." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.

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.
Ph. D.

博士
國立臺灣海洋大學
河海工程學系
94
Abstract In recent years, changes of the global environment and climate have resulted in sudden increase of water turbidity and hence no water supply whenever there is a storm. During the dry season or a drought, on the other hand, there is shortage in water resources. These have emerge a challenge for water supply at water sources. Therefore, this research considers district water supply systems(including the water supply station) in the future to allocate multiple water sources and quickly supply water to different districts or supply water with less quantity and optimal pressure to maintain the basic domestic water consumption of the public. This research applies the concept of system life cycle in developing a stable, diversified and informative water supply system to achieve least water supply risk, highest stability, and lowest cost. The comprehensive problems of water supply and tries to come up with solutions. Methods adopted include (1) Developing and building district water supply systems to mainly accommodate multiple water sources allocation. Two parallel pipes and connecting piping are established on major water supply pipes of the allocation system and two wells are set up in each district piping network to connect with major water supply pipes of different piping. Other parts and tubing or piping outside each district are completely separated. The improved district piping networks can supply water independently and instantly carry out water supply allocation as well as assure efficacy of reasonable supply water pressure. (2) Doing the hydraulic power simulation analysis and establishing an optimal model, taking into consideration the initial piping setup charge, road repair charge and management and operation charge to achieve minimum cost and maximum water supply. Meanwhile, inspired Genetic Algorithm is applied to find the solution and find a more cost-effective design proposal in compliance with design regulations and principles. (3) Mapping out the support system of the multiple water supply station in the district, which in ordinary times supplies users with multi-alternative drinking water (such as magnetized water, and oxygenated water) or meet the basic demand for drinking water of the public in case of emergencies where the station cannot supply water to ensure maximized reliability in water supply. This research analyzes the optimal setup location of the water supply station by Fuzzy C-Means Algorithm for each supply station can make the best use of. (4) We want to look for monitoring stations ,That number and sites of of stations can be obtained by Policy-making model of simulating site selecting of the district urban water network. Then setting monitor systems in districts to exactly control water input and output and the optimal water pressure, minimize water leaks, check on water leaks or water pollution in the districts, and make sure that water pressure and quantity are stable. If the piping network is abnormal or is broken, the leaking spots can be located very quickly and repairs can be made to restore normal water supply in a rapid manner. Analyses show that this method saves water loss as a result of broken pipes by 67% and cuts down leak volume by more than 23.5% when water pressure is controlled at a reasonable level. Through case study and analysis, this research finds that the shortage risk of major water supply pipes and the district piping network itself in a district piping network system management model drop to 0.018 from 0.202 when a monitor system is added; that is, improvement in the district piping network system can result in 1.23 times of increase in water supply reliability. Therefore, if the water within water supply districts is decreased or cannot be supplied completely due to natural disasters or other situations, the improved small district piping network system established in this research (including the water supply station system) could be used to provide the public with basic domestic water and maximize the water supply efficacy in the district. Keyword: Districted Water Supply System , Life Cycle, Optimal Model, Fuzzy C-Means Algorithm, Reliability, Shortage Risk

碩士
國立交通大學
土木工程系所
101
This study proposes a framework to evaluate the water supply system reliability through life cycle assessment and system reliability theorems. Water supply systems in Taiwan mainly consist of three major subsystems: (1) raw water from reservoirs, (2) treatment plants, and (3) distribution networks. Reservoirs provide raw water, and water treatment plants convert raw water into drinking water that is later distributed to consumers through distribution networks. Reliability of water supply systems is composed of water quantity and quality. Mechanical failures occurring in the water treatment and distribution sections potentially lead to water supply system failures in terms of water quantity and quality; therefore, this study takes into account the mechanical failures that affect water supply system reliability. Life cycle assessment and system reliability theorems are employed to evaluate the water supply system. Shihmen Reservoir water supply system is hypothetically taken as a case study.

碩士
國立臺灣大學
土木工程學研究所
88
Abstract The study aims at building up a set of research methodology to estimate the reliability of regional water supply system when ENSO occurs. This research methodology is also applied on Tan-Shui river basin so as to highlight practicability of this methodology. The study firstly introduces the definition and occurrence of ENSO. Furthermore, the cause of building research methodology is illustrated: (1) 30 sets of Nino3.4 Index of defining ENSO are generated by Thomas and Fiering seasonal model. (2) Two regression equations, one is between Nino3.4 Index and temperature, the other is between Nino3.4 Index and precipitation, are separately established. (3) Runoff is simulated by inputting temperature and precipitation into the water balance model. (4) Water supply of each demand note is gained by optimization model. (5) Shortage index (MSI) is evaluated by water supply and demand. And (6) the reliability of water supply system is estimated by MSI The study applies the methodology on Hsintien Stream Region and Tahan Stream Region to estimate the reliability of satisfying each target demand in the research area under current (Year 1996) water demand and water resource facilities. Before applying the methodology, both model validation and parameter calibration are done in order to obtain the parameters of each model. The methodology of study is applied to obtain following conclusions: (1) the trend of correlation between Nino3.4 Index and temperature is similar with it between Nino3.4 Index and precipitation. They are both weak correlated in the same month. However, they are stronger correlated in one month lag and the strongest in two months lag. (2) The study discovers that ENSO affects rainfall in northern and middle Taiwan more obvious than in other sections, but litter different in temperature between regions. (3) The water shortage condition is more serious in Tahan Stream Region than Hsintien Stream Region under current (Year 1996) water demand and water resource facilities. (4) In Tahan stream region, The reliability of MSI, which is 0.1, is 50.35%; which is 0.5 is 78.35%; and which is 1 is 95.58% under current (Year 1996) water demand and water resource facilities. (5) Hsintien Stream Region is not shortage in water demand. (6) In whole region, the reliability of MSI, which is 0.1, is 66.35%; which is 0.2 is 82.47%; and which is greater than 0.3 is 93.44% under current (Year 1996) water demand and water resource facilities.

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.

碩士
國立交通大學
土木工程學系
101
Raw water sources in Taiwan mainly come from reservoirs. Water treatment plants are commissioned to purify raw water to become drinking water. Through water distribution network, purified water can be delivered to the water consumers. Recently, the high turbidity of raw water induced by intensive rainfalls overloads the water treatment plants and causes water supply temporarily disrupted in the Shihmen Reservoir water supply area. Previous studies generally focus on the quantity of water rather than its quality. As consequence, it leads to underestimate the risk of water shortage and overestimate the resiliency, and vulnerability. This study presents a water supply system reliability analysis methodology and develops its evaluation model that takes into account both quality and quantity of water. Historical flow records and data generated by the time series model are both used in the water supply system reliability evaluation model. Results show that the indices such as water shortage index, resiliency and vulnerability increase if raw water turbidity is considered. Conversely, the reliability of water supply system reduces. Though the effect of higher turbidity is not found significant on system reliability in long term, short term events such as typhoons that can cause high turbidity still cannot be ignored.

The Texas Commission on Environmental Quality (TCEQ) uses a Water Availability Modeling System (WAM) to support long-term regional and statewide water resources planning and management. The water availability studies are based on the modeling capabilities of the Water Rights Analysis Package (WRAP). This research improves the understanding of decision support tools for short-term river basin management. Current reservoir storage levels must be considered to assess short-term frequencies and reliabilities. Conditional reliability modeling (CRM) is used to assess the likelihood of meeting targets for instream flow, reservoir storage, water supply diversion and hydroelectric power generation in the near future (next month to next several years), conditioned upon preceding storage. This study uses data for the Brazos River Basin from the TCEQ WAM System to assess key complexities of water supply reliability analysis in general and conditional reliability modeling in particular. These complexities include uncertainties associated with river basin hydrology, estimating yield-reliability relationships for individual reservoirs and multiple reservoir systems, conventional long-term planning versus short-term adaptive management and other modeling and analysis issues. The modeling capabilities of WRAP were expanded to support near real-time operation of dams under various stream flow conditions. The sensitivity to changes in modeling options is assessed for short and long-term simulations. Traditional and newly developed methodologies for estimating firm yields and water supply reliabilities are evaluated. Guidelines are developed regarding the practical application of firm yield analyses and conditional reliability modeling. Important applications of this research include real-time decision support during drought and routinely recurring operational planning activities. A case study of the drought of 2009 uses the CRM features of WRAP for these applications.

This study uses the double-bounded bid elicitation format to test whether the location of water source points significantly influences households? WTP for improved water supply reliability in Maseru City, Lesotho. Maseru was purposely selected on account of its documented water supply unreliability problems that cause suffering and welfare losses to households. WTP was thus elicited when location of the water source points was on-yard, and when it was communal. Purposive and random sampling methods were used to collect survey data from 104 households that access water from on-yard sources, and 107 households that access water from communal sources, making a total of 211 households. The analysis shows that Maseru households have high levels of factual knowledge on challenges associated with unreliable water supply, and display attitudes and perceptions that are receptive to a policy designed to redress the status quo. The mean WTP was 1M1.49 per 20 litre jerrycan (LB M1.38 and UB M1.59) when location of water source points was on-yard, and M1.39 per 20 litre jerrycan (LB M1.30 and UB M1.47) when location of water source points was communal. The null hypothesis of equality of the two mean WTP values could only be rejected at the 10 % level of significance (t = 1.44, p = 0.076), suggesting that location of water source point might not be a powerful determinant of household WTP. This could possibly be attributed to the fact that the welfare losses associated with unreliable water supply might not powerfully discriminate between households based on the location of water source points. The study further established that mean WTP for water supply reliability was higher than what households currently pay for water. For example, households currently pay M0.10 per 20 litre jerrycan to the Water and Sewerage Authority (WASA) of Lesotho when they access water on-yard or from communal sources. In addition, households pay a minimum of M1.00 per 20 litre jerrycan when obliged to buy water from vendors when water is not available from regular sources. Given that the analysis shows that households are WTP up to M1.49 per 20 litre jerrycan for improved water supply reliability, it appears that a policy that improves water supply reliability at a fee would result in a Pareto improvement. Double-bounded models, differentiated by location of water source points, were used to determine factors that influence households? WTP. Results show that WTP is positively related to the following variables: age and educational level of household head, monthly income, average duration of water supply interruption, time spent making a round trip to alternative sources of water during supply interruptions, households? level of awareness regarding past unsuccessful attempts made by WASA to improve water supply reliability, and household perceptions regarding enactment and passing of a parliamentary bill that improves water supply reliability. WTP was negatively related to period household has lived in the current house and gender (males had a less WTP than females). It can thus be concluded that households have a positive WTP for improved water supply reliability, and that their mean WTP for the same is higher than what they currently pay for water. In addition, location of water source points is not a strong determinant of WTP. Following from the above, the study recommends that WASA should consider investing in projects that improve water supply reliability, and in particular ensure that whenever supply is interrupted, the interruption does not last for more than one day per month. To fund such a scheme, the analysis suggests that WASA could consider levying a fee that ranges between M1.00 and M1.60 for each 20L jerrycan. The actual value of the fee should, however, be determined through a stakeholder engagement process. Finally, additional studies would be required to determine important factors that influence households? WTP for improved water supply reliability.
Dissertation (MSc Agric)--University of Pretoria, 2016.
tm2016
Agricultural Economics, Extension and Rural Development
MSc Agric
Unrestricted

碩士
國立海洋大學
航運管理學系碩士在職專班
91
Water is connected with everybody’s daily life. The quality of the drinking water is essential to all the people. Its key factors conclude water quality, water pressure and water quantity. The water- pipe distribution network, though broken at times, is usually not repaired in time, so it stained water quality and caused loss of the water quantity, which leads to the reduction of water pressure or cannot supply drinking water at all. Therefore, consumers tend to misunderstand and feel discontent for water supply system. The research has two purposes. One is to analyze the leakage rate of every district, and the other is to calculate the reliability of every district for water supply system. Subject to the optimal economic principle of the water- pipe distribution network, water supply system can fully satisfy consumer’s demand. I hope that the research can offer managerial reference for every water supply system in shortening expenditure. First, the means and contents of the research are to collect all details of the table for water supply network district, water pressure, water quantity and broken pipe leakage. They are all related to the water pipe number, which can provide the inquired details according to different conditions in Access. At the same time, I make use of SPSS or EXCEL to analyze the above mentioned details. The main conclusions of the research are the following: The leakage ratios and leakage quantity of Hou-tung, Chin-kua-shih… five districts etc I suggest that they must be inspected seriously. The reliability of every district for water supply system and the age of the pipe that the ratio of broken pipe over 1 and the age of the pipe over 30 years have 7 pieces. The above will lower the reliability of the water supply system, so I suggest that they must be replaced with priority.

碩士
國立交通大學
土木工程系所
107
This study aims to develop a model for assessing the reliability of resulting irrigation-water supply from a water allocation model by means of uncertainty and risk analysis under consideration of variations in the water demand for irrigation, inflow from river, outflow into hydraulic structures, and opening height of canal gates. The aforementioned reliability is regarded as the probability of supply water exceeding a specific magnitude. In detail, the proposed reliability assessment model consists of two equations, i.e. the relationship between irrigation-water supply and uncertainty factors and calculation of probability of exceeding a water demand (i.e. reliablity), the effect of aforementioned uncertainty factors on the irrigation water at a number of branches within irrigation region of interest should be accordingly quantified and evaluated. Zhudong canal located within the Touqian river watershed in northern Taiwan are selected as the study area. Regarding the Zhdong Canal, runoff from Shanping Weir is major inflow, and 15 branches in association with the water gates, two reservoirs (i.e. Baoshan and Baoshan II) as well as a water purification plant (i.e. Yuandon) are taken into account in the establishment of water allocation model, RIBASIM model. Additionally, two types of uncertainty factors, hydrological factors (i.e. Inflow from Shanping Weir, outflow into reservoir and water treatment plants) and irrigation features (maximum diverted flow for gate and irrigation-water demand regarding branches) are adopted in the proposed model. After that, 1000 simulations of uncertainty factors are obtained through the Multi-variates Monte Carol method and they are then imported into the RIBASIM to estimate the decade-based (10-day) water supply for entire branches in the Zhudong canal. By doing so, the exceedance probability (i.e. reliability) of simulated irrigation-water supply for entire branches can be computed by using the advanced first order and second moment (AFOSM) approach integrated with the relationship of irrigation-water supply with the uncertainty factors derived by the multi-variate regression analysis. Eventually, the equation of calculating exceedance probability of irrigation-water supply can be obtained through the logistic regression analysis. In this study, sensitivity analysis for irrigation-water supply is carried out by using the normal regression equation with 1000 simulations of irrigation-water supply at all branches. This reveals that the estimated irrigation-water supply is significantly sensitive to the inflow from Shanping Weir, outflow into Banshan reservoir and Yuandon plant, and the maximum diverted flow. According to the results from the risk analysis, the variations in the above four uncertainty factors markedly impact the reliability of irrigation-water supply for all branches in the Zhudong canal. This can be known that more inflow from Shanping weir can effectively enhance the reliability of irrigation-water supply at entire branches. However, the variation in outflow into the Baoshan reservoir impacts the reliability of irrigation-water supply, especially for the upstream braches from the Baoshan reservoir, i.e. the 8th – 14th branch, of which the reliability of irrigation-water supply declines with more outflow form the Zhudong canal into the Baoshan reservoir. Nonetheless, dissimilar to the Baoshan reservoir, the irrigation-water supply at the 1st-3rd branch is obviously proportional to the outflow into the Yuandon water-treatment plant. This implies that at the 1st-3rd branch, the irrigation water can be supplied with high reliability as a result of outflow into Yuandon water-treatment plant exceeding its demand of interest. Moreover, in accordance with the coefficient of variation (CV) for the irrigation-water supply, 15 irrigation branches within Zhudong canal can be classified into three groups nearby: the 1st -2nd branch (group 1), the 3rd-7th branch (group 2) and the 8th-14th branch (group 3) separated at the the Yuandon water-treatment plant and Baoshan Reservoir, respectively. In summary, the proposed reliability-assessment model for irrigation-water supply at branches in the Zhudong canal can reasonably describe the change in the reliability of irrigation-water supply at entire branches in the Zhudong canal attributed to uncertainties in hydrological factors and irrigation features. Therefore, it is expected that results from the proposed reliability-assessment model can be taken reference to the regulation of strategy for drought mitigation. In addition, the change in uncertainty factors, including the inflow from the Shanping weir, outflow into Yuandon treatment plant and the maximum diverted flow for each branch obviously and positively influence the exceedance probability distribution of irrigation-water supply. Above three uncertainty factors can increase the reliability of irrigation-water supply by increasing their amount, excluding outflow into Baoshan Reservoir which is inversely related to the exceedance probability of irrigation-water supply (i.e. reliability).

碩士
國立交通大學
土木工程系所
104
This study aims to develop a reliability assessment model for water supply from the reservoir (RA_WS_Res) in order to quantify the risk of water supply due to the uncertainty factors. The uncertainty factors group into three types: hydrological factors, reservoir operation rules, and parameters of rainfall-runoff model (i.e. Sacramento Soil Moisture Accounting, SAC-SMA). Specifically, the hydrological factors includes the rainfall characteristics, baseflow, evaporation, and initial water level of dam; the reservoir operation rules involve the flood level, target level and firm storage level. In detail, the proposed RA_WS_Res model primarily employs the multivariate Monte Carlo simulation (Wu et al., 2006) to generate the uncertainty factors in order to produce dam inflow by incorporating with the SAC-SMA model. After that, the water supply at the demand nodes of interest can be obtained from the water-resource allocation model (River Basin Simulation model, Ribasim). Using the simulated uncertainty factors and corresponding estimated water supply, the resulting exceedance probability (i.e. insufficient risk) can be calculated by using the uncertainty and risk analysis (i.e. advanced first-order and second moment, AFOSM). Eventually, this study carries out the logistic regression analysis to establish the relationship between the exceedance probability and average rainfall intensity for various 10-day periods at the specific nodes. This relationship is named the exceedance probability calculation equation. In summary, the proposed RA_WS_Res model is composed of five components: simulation of uncertainty factors, estimation of dam inflow, estimation of water supply, quantification of insufficient risk, and establishment of the exceedance calculation equation. It is expected that the proposed RA_WS_Res model can quantify the effect of variation in uncertainty factors, especially due to climate change, on the reliability of water supply from the reservoir. 　　Shihmen Reservoir watershed is selected as the study area and six demand locations within the watershed are selects as the study nodes. In addition, the hourly rainfall data from 1987 to 2014 and associated hydrological data (i.e. evaporation and baseflow) as well as the operation rules are used in the model development and application. The results indicate that, amond these uncertainty factors, the reliability of water supply is more sensitive to uncertainties in the initial water level, average rainfall intensity in each 10-day period, baseflow and the range between the target level and firm storage level. In detail, the effect of variation in the initial water level to water supply gradually reduces with time (ten days) from the 1st ten-day to the 15th ten-day period in Shihmen Reservoir. Moreover, the average rainfall intensity and baseflow are positively related to water supply; this implies that the baseflow plays an important role in the estimation of water supply, besides the average rainfall intensity. In particular, the range between the target and firm storage levels has significantly influence on the reliability of water supply. This reveals that regulating the operation rules for the reservoir not only focuses on the flood mitigation and prevention, but also takes into account the water-supply reliability. Consequently, the proposed RA_WS_Res model can effectively and reasonably quantify the insufficient risk (i.e. exceedance probability) of water supply attributed to variation in uncertainty factors due to climate change; this can be useful for the water-resource allocation and analysis.

In most of the urban cities of developing countries piped water supply is intermittent and they receive water on alternate days for about few hours. The Unaccounted For Water (UFW) in these cities is very high due to aged infrastructure, poor management and operation of the system. In the cities of developing countries, supplied water is not able to meet the demand and there is huge gap between supply and demand of water. To meet the water demand people are depending on other sources of water like groundwater, rain water harvesting, waste water treatment, desalination etc. Huge quantity of groundwater is extracted without any account for the quantity of water used. The main challenge for water authorities is to meet the consumer demands at varying loading conditions. However, the present execution of decisions in the operational management of WDS is through manual control. The manual control of valve throttling and control of pump speed, reduces the efficiency and operation of WDS. In such cases, system modeling coupled with automated control can play a significant role in the appropriate execution and operation of the system. In the past few decades, there has been a major development in the field of modeling and analysing water distribution systems. Most of the people in Indian mega cities are facing water problems as they are not able to receive safe reliable drinking water. In rapidly growing cities, the water resources management has been a major concern for the Government. There is always a need to optimize the available water resources when the rate of demand constantly beats the rate of replenishments. Mathematical modeling of WDS has become an indispensible tool since the ages to model any type of WDS. Development of mathematical models of WDS is necessary to analyse the system behavior for a wide range of operating conditions. Using models, problems can be anticipated in proposed or existing systems, and solutions can be evaluated before time, money, and materials are invested in a real-world project. In the present study, we have developed a model of WDS of a typical city like Bangalore, India and analysed them for several scenarios and operating conditions. Bangalore WDS is modeled using EPANET. Before a network model is used for analysis purpose, it must be ensured that the model is predicting the behavior of the system with reasonable accuracy. The process of matching the parameters of the developed model and the field observed data is known as calibration. All WDS require calibration for effective modeling and simulation of the system. Demand and roughness are the most uncertain parameters and they are adjusted repeatedly to get the required head at nodes and flow in the pipes. The calibration parameters usually include pipe roughness, valve settings, pipe diameter and demand. Pipe roughness, valve settings and pipe diameter are associated with the flow conditions and the demands relate to the boundary conditions. For Bangalore WDS, the values of roughness coefficient and demand are available; and the values of valve settings are not available. Hence, this value is estimated during calibration process. Dynamic Inversion (DI) nonlinear controller with Proportional Integral Derivative (PID) features (DI-PID) is used for calibrating WDS for valve settings on the basis of observed flow and roughness coefficient. From the obtained results it is observed that, controllers are capable of achieving the target flow to all the GLRs with acceptable difference between the flow meter readings and the simulated flow. After calibrating any real WDS to the field observed data, it will be useful for water authorities if the consumer demands are met up to certain extent. This can be achieved by using the concept of equitable distribution of water to different consumers. In the urban cities of developing countries, often large quantities of water are supplied to only a few consumers, leading to inequitable water supply. It is a well known fact that quantity of water supplied from the source is not distributed equitably among the consumers. Aged pipelines pump failures, improper management of water resources are some of the main reasons for it. Equitable water to different consumers can be provided by operating the system in an efficient manner. Most of the urban cities receive water from the source to intermediate reservoirs and from these reservoirs water is supplied to consumers. Therefore, to achieve equitable water supply, these two supply levels have to be controlled using different concepts/ techniques. The water requirement of each of the reservoirs has to be calculated, which may depend on the number of consumers and consumer category. Each reservoir should receive its share of water to satisfy its consumer demand and also there must be provision to accommodate shortages, if any. The calibrated model of Bangalore WDS is used to achieve equitable water supply quantity to different zones of Bangalore city. The city has large undulating terrain among different zones which leads to unequal distribution of water. Dynamic Inversion (DI) nonlinear controller with Proportional Integral Derivative (PID) features (DI-PID) is used for valve throttling to achieve the target flows to different zones/reservoirs of the city at different levels. Equitable water distribution to different reservoirs, when a part of the source fails to supply water is also discussed in this thesis. From the obtained results it is observed that, controllers were responding in all the cases in different levels of targets for such a huge network. When there is change in supply pattern to achieve the equitable supply of water to different zones, the hydraulics of the WDS will change. Therefore, it is necessary to understand whether the system is able to handle these changes. The concept of reliability can be used to analyse the performance of WDS for wide range of operating conditions. Reliability analysis of a WDS for both normal and likely to occur situations will give a better quality of service to its consumers. Calculating both hydraulic and mechanical reliability is important as the chances of occurrence of both the failure scenarios are equal in a WDS. In the present study, a methodology is presented to model the nodal, system and total reliability for water supply networks by considering the hydraulic and mechanical failure scenarios. These two reliability measures together give the total reliability of the system. Analysing a real and complex WDS for the probable chances of occurrence of the failure scenarios; and then to anlyse the total reliability of the system is not reported in the literature and this analysis is carried out in the present study for Bangalore city WDS. The hydraulics of the system for all the operating conditions is analysed using EPANET. Hydraulic reliability is calculated by varying the uncertain independent parameters (demand, roughness and source water) and mechanical reliability is calculated by assuming system component failures. The system is analysed for both the reliability scenarios by considering different chances of failure that may occur in a real WDS; and hence the total reliability is calculated by making different combinations of hydraulic and mechanical failure scenarios. Sensitivity analysis for all the zones is also carried out to understand the behavior of different demand points for large fluctuation in hydraulics of the system. From the study, it is observed that, Hydraulic reliability decreases as the demand variation increases. But, as the roughness variation increases, there is no much change in the nodal or system reliability. Consumer demand or reliability of the WDS can be increased by saving the water lost in the system. This can be achieved by tracking the water parcel from the source till the consumer end, which will give an idea about the performance of different stages and zones in achieving the target flows. Huge quantity of water is lost in WDS and hence it is necessary to account for the water lost at different levels, hence the system can be managed in a better way. In most of the intermittent water supply systems demand is controlled by supply side; there is also a need to understand the demand variation at the consumer end which in turn affects the supply. Matching this varied supply-demand gap at various levels is challenging task. To get a better control of such problem, water balance (WB) equations need to be derived at various levels. When we derive these WB equations it should be emphasized that UFW is one of the major component of this equation. Given this back ground of the complex problem, for a typical city like Bangalore, an attempt is made to derive WB equations at various levels. In the present study, stage-wise and zone-wise WB is analysed for different months based on the flow meter readings. The conceptual model developed is calibrated, validated and also the performance of the model is analysed by giving a chance of error in the flow measurement. Based on all the above observations, stage-wise and zone-wise water supply weights are also calculated. From the study it is found that, there is no much loss of water in all the four stages of supply. Water loss is minimal of about 3 % till water reaches from source to GLRs. Water is transferred between the stages during some days of the month, may be due to shortage of water or due to unexpected demand. Huge quantity of water is lost in the distribution main which is of about 40 to 45% for all the moths which is analysed. This type of model will be extremely useful for water supply managers to manage their resources more efficiently and this study is discussed in detail as a part of this thesis. As mentioned above, huge quantity of groundwater is used in urban cities and the quantity of water extracted is not accounted. In the present study, zone wise and sub zone-wise piped water and ground water used in different parts of the cities is analysed with the help of available data. From the study it is observed that, the quantity of piped water supply and UFW is consistent for the time period analysed and the quantity of water withdrawn from the borewells are varying considerably depending on the yield of the borewlls in different zones. The main components of urban water supply are piped water, ground water, rainfall and runoff generated, UFW, waste water produced and other water quantities which may be minute. In future, to manage the water resources properly, integrated water management is necessary in city scale which will give an idea about the total water produced and the water utilized at the consumer end. Therefore, integrated water management concept is carried out in Hebbal region, (a small part of Bangalore) using the available data. From the analysis we noticed that, domestic water supplied to North sub zones are better when comparing to East sub zones. This type of total water balance can be studied in other parts of Bangalore, to understand the behavior of different water components and to make better decisions. The developed model, analysis and operating conditions of this study can be applied to other similar cities like Bangalore. This type of study may be useful to water authorities for better control of the resources, or in making better decisions and these types of models will act as decision support systems.

Errata sheet pasted onto front end-paper.
Bibliography: leaves 357-377.
xxvi, 514 leaves : ill. (some col.), fold. maps ; 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, 1999?

Errata sheet pasted onto front end-paper.
Bibliography: leaves 357-377.
xxvi, 514 leaves : ill. (some col.), fold. maps ; 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, 1999?