ABSTRACT Water scarcity is a fundamental problem in Libya and most parts of the world. Water shortages are often due to problems of uneven distribution and the management of existing water supplies I 11 11 I ~ i in Libya that could be improved. Such studies are not common in Libya's agricultural areas, where most of the economic analyses focus on either domestic or household water demand. The current study attempts to determine the economic value of water to sustain agricultural production by eliciting farmers' willingness to pay for water use under improved water supplies by using choice experiment modelling and explores the potential for water conservation through water-demand management. The multinomial probit model is employed in order to relax the assumption that all farmers have the same preferences for the attributes being valued, which is usually required in empirical choice experiment studies. Farmers included in this study, who largely depend on groundwater, were asked for their preferences on the payment for water use. " Farmers' socioeconomics such as age, education, farm income, farm ownership, water scarcity, irrigated area, water consumption and cost of water pumping have significant influences on farmers' willingness to pay for water use in the agricultural sector. Choice modelling allows estimating the relative importance of these socioeconomics for differences of the studied farmers, and ultimately provides a measure of the willingness to pay for different aspects of water attributes, including the pricing of water for agricultural uses. The estimated value of willingness to pay for using water in agriculture is 0.36 LD/m3, which represents 12 % of the annual farm income. For farmers' willingness to pay estimates, the comparison between costs of farmers pumping water and governmental water supply, found that willingness to pay estimate appear to be a reasonable amount, where this value is lower than the governmental cost of supplied water xv Optimization of Water Use for Food Production and higher than cost of pumping water. The majority of surveyed farmers (61.75 %) reacted positively stating that the in prices of water might enhance in the water use efficacy. Also, the positive view of farmer's perception about pricing of water is one of the important factors that positively influence the willingness to pay. Based on these empirical findings, the study advocates water pricing policy in the agricultural sector in order to enhance the efficiency and promote sustainability in water use for agricultural production in Libya. xvi.

In Malaysia, the water management system was restructured in January 2005 by the transfer of water supplies and services from the State List to the Concurrent List. The National Water Services Commission or Suruhanjaya Perkhidmatan Air Negara (SPAN) was established in July 2006 as the technical and economic regulator for the improvement of water supply quality and the efficiency of the water industry. This study focuses on SAJ Holdings (SAJH). This water supply company provides a fully integrated service, i.e. it is involved in the all the processes of drinking water supply; these range from raw water acquisition, treatment and purification, and the subsequent distribution of purified water to customers, plus billing and payment collection. This study attempts to assess the residential customers‟ preferences of different attributes of water supply. The water attributes are divided into two categories: Water Infrastructure (WI) and Residential Customers (RC). WI attributes are leakage, pipe bursts, and reservoirs; RC attributes are water quality, pressure, connections, and disruptions. Choice modelling (CM) was applied as a tool for the assessment of effective demand for improved water supplies, particularly by residential customers. There are two econometric models employed: Conditional Logit (CL) and Mixed Logit (MXL). Face-to-face interviews were conducted with residential customers and Statistical Analysis Software (SAS) was used in order to analyse the data. The model consists of a basic model and an interaction model with socioeconomic characteristics. The findings show that the significant variables affecting demand are pipe bursts, (BUR), water quality (QUA), disruption (DIS) and connection (CON), as well as price (PRI). Among the socioeconomic characteristics that interact with the main attributes are gender, age, number of children, type of house, number of persons in the household, education, work, and income. This information is very useful for the water provider when upgrading the water service for valuable customers.

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High fluoride in drinking water sources is a problem throughout the East African Rift Valley and can lead to dental fluorosis and skeletal fluorosis in exposed local populations. One such area is the Hai District of Northern Tanzania. The study began by mapping the concentrations of fluoride in drinking water across the Hai district. Measured at 152 locations, fluoride concentrations varied from <0.1 mg/L to 33.2 mg/L, with a mean value of 1.6 mg/L. 12.5% of samples had fluoride above the World Health Organization recommended water quality standard (1.5 mg/L). Along with mapping the levels of fluoride, rock samples were also taken in an attempt to identify the source of the fluoride. Rock samples taken from areas with high levels of fluoride in the drinking water contained fluorite that shows textural evidence of dissolution. Other geological evidence from studies in a neighbouring district suggest that a geological system only present in part of the Hai district is responsible for the high levels of fluoride in the drinking water. Two villages where fluoride was identified as a problem from the mapping were investigated. The prevalence of dental fluorosis and deformities due to skeletal fluorosis were assessed in children attending school in the two villages. Over 25% of children in each village had skeletal deformities, though one village had much higher levels of fluoride in the drinking water, a mean of 23.5 mg/l compared to 5.4 mg/l) in the other village. Over 99% of children in both villages had dental fluorosis. Deformities relating to skeletal fluorosis are common, but the reasons for individual susceptibility remain unclear and may include low calcium diets, ingestion of magadi (local salt) with high fluoride, or genetic factors. iv The study concluded by considering possible treatment options and installed a bone char treatment plant in the village of Tindigani. Throughout the study, the communities were educated about the issue of fluoride in the drinking water. The village of Tindigani responded by mobilizing to provide piped water for themselves, removing the need for the bone char treatment plant.

The thesis is a treatise of the quantity and quality aspects of potable water in distribution systems. The privatisation of the UK Water Industry in 1989 has seen the requirement for the Water Companies in England and Wales to be responsible for the delivery of good quality water that meets the demand of all consumers. In respect of the quantity of supply, there have been many previous studies that have examined the hydraulic performance of distribution systems and there are now many proprietary mathematical models that have been successfully used in this study. However, in respect of water quality the literature review has highlighted that the modelling approach is not so well advanced, as water quality is a function of many concepts, processes and parameters that include the source and age of water, the condition and deterioration of the assets in the system, the microbiological, chemical and physical processes and the network hydraulic performance, including pressure transients. These processes are highly interactive and complex. In an attempt to better understand these processes a programme of research has been completed that has involved a field evaluation of the performance of a live system, including the development of instrumentation to continually measure water quality, and the development of a mathematical model to describe the processes associated with the age of water and the propagation of conservative and non-conservative substances. An initial attempt has also been made to develop a micro-biological model and a sediment transport model. New original concepts developed by the author include age, biological and diagnostic models that may be used to identify the source of any incident (hydraulic or pollution) and the application of the model in near real time.

The WHO Framework for Safe Drinking-water has been developed from many years of field work and evidence of the challenges faced in the provision of safe diinking-water supply. However, there has been no analysis of the potential of the WHO Framework to improve drinking-water safety in a small island environment. In order to carry out the research, Islands with a broad range of characteristics in a relatively unstudied region were chosen to add to the existing knowledge of the challenges experienced by small islands. An audit of the WHO Framework was then carried out to analyse the potential strategic position it may have in the small island environment to improve drinking-water safety.

Water Resilience and Water ' Security is of primary importance to society, the economy and the environment at both global and local levels and Sustainable Water Management Systems (SWMS) are acknowledged as the way forward to deliver a multifaceted approach to managing the environmental, economic, and social resource aspects of design for land development. Therefore, a process model is required to explore the linkages and implications of utilising existing ad-hoc water saving technologies such as Rainwater Harvesting, Greywater Reuse and Sustainable Drainage Systems. This study provides a balanced alternative from traditional potable water supply and flood alleviation techniques, by adopting the concept of a secondary water supply, while providing the added advantage of controlling surface water runoff. However, for an evaluation process model to succeed at the planning and design stages there is also a need to have an in-depth understanding of not only legislation and policies, but also the complex multi-variables associated with site location demographics and key stakeholder preference. This Sustainable Water Evaluation Process (SWEP) was developed to integrate these complex variables by providing a quantative, qualitative and economic model analysis, in line with best management practice, assessed against selection scenarios, as defined by the model User. During this study the sustainability awareness and attitudinal change and concerns raised by both stakeholders and expert opinion on engineering and ecological difficulties are addressed through factors that include climate change, economic benefit and social inclusion. Adaptation options within this study illustrate the importance of addressing different socio-economic development scenarios. These scenarios have been demonstrated through a UK case study, which illustrates the advantages, associated with SWMS and reduced utility reliance from the regional network. The outcome of this research demonstrates a process model that is evidence based and provides, protects and promotes the use of combined S WMS practices at the development level to meet site specific conditions. The design decisions facilitate User flexibility while providing the land use planner, developer and designer with a process model for evaluating current SWMS technologies to provide greater emphasis on improved water resource management and the socio-economic issues that address Water Resilience and Water Security at the UK National, Regional and Local levels.

Growth in population and households, and lifestyle changes are factors placing water resources under increasing stress in some parts of the UK. The Code for Sustainable Homes (CSH), a government regulation defining performance standards for new dwellings, is one measure that may act to counter rising domestic water demand. One goal of the CSH is to reduce potable water use per capita in each home through implementation of water conservation measures. The main aims of the research are to assess what impact the CSH might have on future regional household water demand, and to understand the level of CSH uptake, at various performance levels, needed to achieve Government aspirations of 130 I/c/d. The thesis investigates the effects of implementation of the CSH on regional domestic demand in the area served by Yorkshire Water Services (YWS). The uncertainty surrounding CSH implementation means it was necessary to study . a range of possible futures comprising aspects of the technology implied by the CSH, demography and construction trends. A spread sheet model was developed to assess domestic water demand under a range of CSH uptake scenarios, as well as a range of demographic, technical, economical and behavioural aspects of water consumption and conservation. One finding was that not even building the total amount of planned dwellings to the highest performance level of the CSH will suffice to achieve the Government target; hence backcasting scenarios were also developed in order to asses to what extent water conservation strategies in the extant stock together with the CSH in the new stock can help achieve the target for 2030. The work explores feasible scenarios considering physical constraints, costs and people's acceptability.