Showing papers on "Water supply published in 1985"

International Institute for Applied Systems Analysis, A-2361 Laxenburg, Austria

Abstract: The impact of open-pit lignite mining on water resources creates significant conflicts between different interest groups, such as the mining industry, water supply agencies, and agriculture in the mining region. The activities of each of the interest groups modify the water resources system and at the same time the conditions for resources use by other groups. Consequently, there is an apparent need for the analysis of regional water policies to reconcile the conflicting interests within such socio-eeonomic environmental systems. On that, a collaborative study between the International Institute for Applied Systems Analysis and Research Institutes in the German Democratic Republic (GDR) and Poland is directed.

Irrigation water quality criteria

Abstract: This chapter focuses on how to evaluate the chemical quality of treated wastewater for use in irrigating plants. The quality of treated municipal wastewater depends to a great extent on the quality of the municipal water supply, nature of the wastes added during use, and the degree of treatment the wastewater has received. There are no specific requirements in California on the frequency of sampling reclaimed wastewater used for irrigation. The primary factor in evaluating water quality for irrigation is the quantity and kind of salt present in the water supplies. As salinity increases in the reclaimed wastewater used for irrigation, the probability for certain soil, water, and cropping problems increases. Salinity, measured by electrical conductivity, is the single most important parameter in determining the suitability of water for irrigation. Occasional problems of abnormal pH, corrosion of pipelines and equipment, irrigation water system clogging and high residual chlorine occur when using reclaimed wastewater is used.

A User-Orientated Model of the Soil Water Balance in Wheat

Abstract: In many regions of the world where agriculture is important, the season for growing crops is often characterized by large variations in water supply. These variations occur both spatially and from year to year. This uncertainty in water supply, along with other important weather variations, creates a risky environment for farmers. Models that consider the dynamics of the soil water balance as related to weather, plant and soil parameters have been proposed as a means of assisting farmers in minimizing their risks.

Feasibility and efficacy of in-home water chlorination in rural North-eastern Brazil.

Abstract: The purpose of this study was to assess the feasibility, acceptability and effect of an in-home water chlorination programme in a rural village. Previous studies at this site showed high levels of faecal coliforms in household water, high diarrhoea rates in children, and enterotoxigenic Escherichia coli and rotaviruses were the most common pathogens isolated from patients. Household water came from a pond and was stored in clay pots. No homes had sanitary facilities. A blind, cross-over trial of treatment of household water with inexpensive hypochlorite by a community health worker was carried out over 18 weeks among 20 families. Water in the clay pots was sampled serially, and symptom surveillance was done by medical students. The programme was generally acceptable to the villagers and no change in water use patterns were apparent. The mean faecal coliform level in the chlorinated water was significantly less than in the placebo treated samples (70 vs 16000 organisms/dl, P less than 0.001). People living in houses receiving placebo treatment had a mean of 11.2 days of diarrhoea per year, and the highest rate of 36.7 was among children less than 2 years old. Diarrhoea rates were not significantly different among the participants while exposed to water treated with hypochlorite. We conclude that a low-cost programme of this type, which utilizes community resources, is logistically feasible, appears to be culturally acceptable in this setting, and can result in a marked reduction in water contamination. The lack of effect on diarrhoea rates suggests that improvement in water quality may affect morbidity only when other variables relating to faecal-oral agent transmission are ameliorated at the same time.

Multi-controlled water conservation system for hot water lines with low pressure utilization disable

Abstract: A water conservation system for use in residential dwellings or other buildings having a hot water distribution system. The system conserves water which is typically wasted by users while waiting for warm water to flow from a hot water faucet. The system provides a recirculating cooled hot water supply line from the cooled-off end of a hot water line back to the hot water heater of the hot water distribution system. The system is provided with a plurality of control means to electrically energize the system's recirculating pump so long as a pressure switch detects that the main water supply is providing sufficient water pressure to the system. In operation the recirculating pump opens a check valve in the recirculating line and closes the check valve in the main water supply line and recirculates the cooled hot water back to the hot water heater for ultimate use. If the main water supply has insufficient pressure, the recirculating cooled hot water system is non-functional.

Expression for Drinking Water Supply Standards

Abstract: Various authorities and regulating agencies have set standards for deciding the suitability of a water for drinking purposes. These standards prescribe the permissible concentrations of quality variables. When some variables exceed the permissible levels, a decision for permitting further use of the water supply has to be based on the importance of those variables with exceeded concentrations. It is proposed that standards for a drinking water supply should be set through a single number representing the integrated effect of all the variables, keeping due regard to the importance of each variable. Such an integrated water quality index (WQI) would help in decision making. Models and curves have been presented to evolve a WQI for drinking water supplies. It is suggested that water with a WQI lower than 90 should not be permitted. The acceptable quality therefore, should be in the 90–100 range of the WQI.

Water management: Technology and institutions

Abstract: This text is suitable for an introductory course in water resources management or water supply engineering at the undergraduate or first year graduate level. Subjects considered include surface water and groundwater quality issues, hydrology, reuse of wastewater, and large-scale water conveyance systems. Includes chapter problems, references for further study, 4 appendixes, and a subject index. Contents, abridged: Water resources development from 1900 to 1980. Water resources planning. Natural water supply processes. Augmentation of water supplies. Water conveyance and storage. Index.

Financial and Economic Irrigation Net Benefit Functions for Egypt's Northern Delta

Abstract: Estimates of financial and economic net benefits to irrigation water supply are shown for a case study area in the northern Nile delta region of Egypt. Linear programming models of representative farms in the study area are formulated with particular attention to the possibilities of using less water per crop as well as shifting crops in response to hypothetical reductions in water supply. Net benefits are defined as gross revenues minus costs of production, including an imputed charge for family labor. Model solutions are based on both 1980 government prices with production controls (financial net benefits) and hypothetical 1980 international market prices with relaxed controls (economic net benefits). Five different water supply scenarios are analyzed: from the current, adequate level of supply, down to a 40% reduction from that level. Total, average, and marginal net benefit functions are reported. Implications of the differences between the financial and economic benefit functions for farmers are discussed.

Reliability and Risk Assessment for Water Supply Systems

Abstract: Analytical methods for computing the reliability of water supply systems are described and demonstrated. A case study serves to show how risk, which is the economic loss due to shortfalls, can be assessed and incorporated into the decision making on capacity expansion aimed at improving supply reliability.

Planning the Netherlands' Water Resources

Abstract: A comprehensive, integrated system of 50 models was developed to evaluate policies that include mixes of building new facilities and changing operating rules to improve water supply, as well as adjusting prices and regulations to reduce demands. Analysis performed with the system resulted in a new national water management policy, saving hundreds of millions of dollars in investment expenditures and reducing agricultural damage by about $15 million per year, while decreasing thermal and algae pollution. The methodology was adopted by the Dutch government and has been used to train water resource planners from many nations.

Computer Modeling of Distribution System Water Quality

Abstract: The WADSY-Q computer program was developed as a tool to analyze water quality patterns in water distribution systems with multiple sources. The program calculates the concentrations of conservative parameters at any point in a modeled network, for steady-state conditions and known source concentrations. The program provides an efficient means of evaluating the water quality impacts of supply alternatives being considered to meet future demands. This information helps provide a more complete picture of benefits and costs so that prudent management decisions can be made.

Effects of water quality and water quantity on nutritional status: findings from a south Indian community

Abstract: Quantitative assessments of the relative effects on health of various aspects of water supply are virtually absent from the literature. Despite the lack of information, resources are being allocated throughout the developing world, for projects related to water and sanitation. The present study was designed specifically to overcome many of the methodological problems that other researchers have faced. Data were collected concerning the nutritional status of 627 children in three urban communities in South India. Information was also collected on water quality, water quantity, household sanitation, socioeconomic conditions, and housing. A statistical technique is presented that allows for controlling potential confounding factors in the analyses. The results, in general, indicate that at young ages (i.e., under 3 years old) water quality is relatively more important as a determinant of nutritional status, while at older ages water quantity is relatively more important.

Nationwide occurrence of radon and other natural radioactivity in public water supplies

Abstract: The nationwide study, which began in November of 1980, was designed to systematically sample water supplies in all 48 contiguous states. The results of the study will be used, in cooperation with EPA's Office of Drinking Water, to estimate population exposures nationwide and to support possible future standards for radon, uranium, and other natural radioactivity in public water supplies. Samples from more than 2500 public water supplies representing 35 states were collected. Although we sampled only about five percent of the total number of groundwater supplies in the 48 contiguous states of the US, those samples represent nearly 45 percent of the water consumed by US groundwater users in the 48 contiguous states. Sample results are summarized by arithmetic mean, geometric mean, and population weighted arithmetic mean for each state and the entire US. Results include radon, gross alpha, gross beta, Ra-226, Ra-228, total Ra, U-234, U-238, total U, and U-234/U-238 ratios. Individual public water supply results are found in the appendices. 24 refs., 91 figs., 51 tabs.

Pricing and Expansion of a Water Supply System

Abstract: A general model for constrained optimum water pricing and capacity expansion is applied to the twin cities of KitchenerWaterloo KW, Ontario. The model identifies the water price and water supply ca...

Effects of Instream Flow Requirements on Water Supply Reliability

Abstract: Increasing water demands have directed new interest toward methods for defining water supply system performance. These demands include not only traditional municipal, industrial, and agricutural demands, but instream flow uses such as power production and fish flow maintenance. This paper suggests procedures for evaluating water supply performance when instream flows for fish are required of a municipal water supply. A computer simulation model is used with synthetic inflow sequences to investigate indices of system performance for the Seattle, Washington water supply system. A review of techniques used to establish instream flow requirements is presented with a history of instream flow requirements established for the Seattle supply. The trade-offs between values of instream flows and municipal water supply performance are presented to quantitatively illustrate the impacts of instream requirements.

Non‐conventional Water Resources

Abstract: This two-part article gives an overview of the use of non-conventional water resources in developing countries. The first part presented below reviews United Nations involvement with the subject and its relationship to the International Drinking Water Supply and Sanitation Decade. The main emphasis of the first part is on the development of technology and markets for the various desalination processes — distillation, electrodialysis and reverse osmosis. The general costs of the various processes are compared. The second part of the article (to be published in the April 1985 issue) concentrates on the other non-conventional water resources: transport of water by tanker and iceberg, waste water re-use and weather modification. For all the processes, examples are given and economic comparisons are made. It is concluded that it is always preferable to use conventional resources where available. However, in water-short areas, consideration might be given to the available non-conventional resources, and economic and technical comparisons made, before a final choice is reached.

Calculating Effectiveness of Water Conservation Measures

Abstract: Implementation of water conservation programs can result in significant savings to water utilities. Engineers and planners working with utilities need to be able to predict the reduction in water requirements (i.e., effectiveness of water conservation) that will result from implementation of water conservation measures. A procedure that was developed to help predict water conservation effectiveness for typical conditions is presented.

China's water resources and its utilization

Abstract: By recent estimation, the total annual runoff in China is about 2,638 km3, corresponding to 2,670 m3 per capita. The water problems of China are due to the uneven distribution of water resources and rapid increase of water demand, which have brought many difficulties in flood control and water supply. In this paper, characteristics of water resources and present situation of water resources development, conservation and utilization are discussed.

Volumetric Pricing of Agricultural Water Supplies: A Case Study

Abstract: Models of water consumption by rice producers are conceptualized and then estimated using cross-sectional time series data obtained from 16 Texas canal operators for the years 1977–1982. Two alternative econometric models demonstrate that both volumetric and flat rate water charges are strongly and inversely related to agricultural water consumption. Nonprice conservation incentives accompanying flat rates are hypothesized to explain the negative correlation of flat rate charges and water consumption. Application of these results suggests that water supply organizations in the sample population converting to volumetric pricing will generally reduce water consumption.

Computer Applications in Water Resources

Abstract: The use of computers in all engineering disciplines has, in the past decade, increased to the point where virtually all engineers now use these powerful tools. This is especially true in the water resources field. The papers included in this book cover computer applications in planning, analysis, forecasting, modeling, operation, and management. These applications are discussed in relation to water resources, water supply, reservoirs, pollutant transport, groundwater flow, hydraulic networks, water utilities, water distribution systems, river basins, lakes, and flood control. Interactive graphics, computer-aided design, data base management, and expert systems are also covered.

The essential role of drinking water and sanitation in primary health care.

Abstract: The purpose of the paper is to draw attention to the fact that drinking water supply and the provision of sanitation facilities form an indispensable element in disease prevention and primary health care programmes. The world situation regarding the availability of drinking water and sanitation facilities is dramatic, in that more than 1500 million people lact proper facilities; the implications in terms of health and cost are stupendous. It is therefore a fortunate development that the International Drinking Water and Sanitation Decade (1981-1990) is on its way to an appealing initiative. The paper discusses water and sanitation related diseases, and the established experience that water and sanitation programmes can only have a health impact if they are jointly developed, and if they are integrated with health education. Operational implications of such programmes as an element of primary health care are reviewed.

Forecasting Water Use: A Tutorial

Abstract: In spite of 4,000 years of public water supply system construction, designs have been customarily based on forecasts of future water use only during the last 100 years. Choices among available forecasting methods are based on issues and criteria developed during that 100 years of forecasting experience. These issues and criteria are examined by reviewing the historical development of forecasting methods, by considering general principles of forecasting, and by incorporating the insights of recent water use research. Topics discussed include the importance of disaggregation in forecasting, the role of price and income, the consequences of changes in household and employment characteristics, and weather normalization.