General Water Resources Research Articles

Development of the WEP-L distributed hydrological model and dynamic assessment of water resources in the Yellow River basin

Dynamic assessment of water resources becomes desirable to reflect water resources variations in the basins under strong human impacts. A physically based distributed hydrological model, WEP-L, which couples simulations of natural hydrological processes and water use processes, is developed for the purpose. Concepts of special water resources (i.e., surface water resources and groundwater resources) and general water resources (i.e., the special water resources plus the precipitation directly utilized by ecosystem) are proposed, and an approach for dynamic assessment of water resources is suggested. Basin subdivision, classification of land covers, and deduction of water use spatial/temporal distributions in the Yellow River basin are carried out with the aid of remote sensing (RS) data and geographic information system (GIS) techniques. The basin is subdivided into 8485 sub-watersheds and 38,720 contour bands, and the WEP-L model is verified by comparing simulated and observed discharges at main gage stations. Lastly, continuous simulations of 45 years (1956–2000) in variable time steps (from 1 h to 1 day) are performed for various land cover and water use conditions, and water resources assessment results under present condition of land cover and water use are compared with those under historical condition of land cover and water use. The study results reveal that: (1) the surface water resources reduced, but the groundwater resources non-overlapped with the surface water resources increased under the impact of human activities in the Yellow River basin; and (2) the special water resources reduced, but the general water resources increased accompanied with increase of the precipitation directly utilized by ecosystem in the basin.

The Parameter Optimization in the Inverse Distance Method by Genetic Algorithm for Estimating Precipitation

The inverse distance method, one of the commonly used methods for analyzing spatial variation of rainfall, is flexible if the order of distances in the method is adjustable. By applying the genetic algorithm (GA), the optimal order of distances can be found to minimize the difference between estimated and measured precipitation data. A case study of the Feitsui reservoir watershed in Taiwan is described in the present paper. The results show that the variability of the order of distances is small when the topography of rainfall stations is uniform. Moreover, when rainfall characteristic is uniform, the horizontal distance between rainfall stations and interpolated locations is the major factor influencing the order of distances. The results also verify that the variable-order inverse distance method is more suitable than the arithmetic average method and the Thiessen Polygons method in describing the spatial variation of rainfall. The efficiency and reliability of hydrologic modeling and hence of general water resource management can be significantly improved by more accurate rainfall data interpolated by the variable-order inverse distance method.

Water and wastewater related issues in Sri Lanka

The primary problems concerning water resources in Sri Lanka are the depletion and degradation of the resource caused by various anthropogenic activities. Surface inland waters in urban areas are polluted heavily with domestic sewage and industrial effluents, and in rural areas with agricultural runoff. With regard to ground water in certain areas of the dry zone, there is a high fluoride content and in hard, rocky, alluvial areas, there is a high concentration of iron. In urban over-crowded cities, there is biological contamination of ground water. Over-utilization, particularly through tube wells, is another major problem affecting ground water resources in Sri Lanka. Oil spills, dumping of waste from ships, coral and sand mining, and activities are the main causes of marine pollution in the country. Except for pipe-borne water supply, irrigation and hydropower schemes, in general water resources in Sri Lanka are managed very poorly. Regulations are available to control most water related problems but enforcement of these regulations is lacking. The ultimate result of degradation and depletion of water resources is the increasing health hazards. Water-borne and vector-borne diseases are prevalent, particularly amongst urban low-income communities with poor sanitary facilities and drainage. Despite government initiatives and legislation, very slow progress has been made towards combating water pollution. This paper examines the most significant water and wastewater related issues in Sri Lanka and their controlling mechanisms.

Iron and manganese dynamics in lake water

The speciation and fractionation of iron and manganese compounds from Hinze Dam water samples (Gold Coast City, Queensland, Australia) were studied using atomic absorption spectrophotometry (AAS), electron paramagnetic resonance spectroscopy (EPRS), gel filtration, ion-exchange chromatography, ultrafiltration and various acid digestion regimes. Samples were taken at various depths and times of year, and both filtrate and particulate samples of water column profiles and sediment samples were analysed. Relevant water quality parameters such as temperature, dissolved oxygen, pH, true colour, turbidity, conductivity and alkalinity were also measured. Following heavy rainfall, dirty water and associated water treatment problems increased as catchment surface erosion and dynamic mixing of the whole water column induced by the introduction of a large volume of rainwater runoff lead to marked increases in particulate matter (mainly carbonates) in the water body. The results obtained before and during artificial aeration were compared at different depths and times of year. Artificial aeration had an initial marked reduction in the levels of soluble iron and manganese in all the dam profiles, however, the concentrations of these metals showed a steady increase over the succeeding years. Statistical analysis of data has been undertaken to correlate the changes between the various forms of iron and manganese with the advent of artificial aeration. Such analyses indicate that a number of traditionally measured water quality parameters have no long-term value for predicting the likely levels of soluble and insoluble iron and manganese, even when correlations between the parameters are calculated on a seasonal rather than on a yearly basis. These water quality parameters are not measured solely for the purpose of prediction, nevertheless, the parameters may be important for real-time treatment process control and for general water resource management. Some important implications for water resource management and water treatment processes are discussed.

Dissemination of Generalized Water Resources Models in the United States

ABSTRACT Federal water agencies and other entities in the United States have invested extensive effort during the past three decades to develop generalized computer models for simulating water resources systems. A great deal of expertise, time, and expense was required to develop these models but they are now available to the professional water management community worldwide at nominal cost. With recent advances in computer technology, most people working in the water resources field have access to desktop computers providing all the hardware capabilities needed to execute the powerful array of available software. Many of these software packages are widely used by public agencies and private firms throughout the United States and in other countries. This paper highlights the availability and role of generalized computer modeling packages and outlines the institutional setting within which the models are disseminated throughout the water management community.

Geographical information system (GIS) environmental models for aquaculture development in Sinaloa State, Mexico

This paper describes the use of a geographical information system (GIS) to construct environmental models for land-based aquaculture development in the State of Sinaloa, Mexico. Based on the source data, submodels were created focusing on three different themes: general environmental issues, water resources and water quality. Models enabled multicriteria and multiobjective decision making concerning site selection and location. In assessing site considerations these general models identified wider resource management options and solved conflicts of land allocation and land use between aquaculture and agriculture. Smaller-scale, more specific models enabled more detailed studies on environmental issues.

A subgradient-based optimization for reservoirs system management

The problem of determining the optimal operating policy for a system of reservoirs equipped with hydroelectric power plants is a nonlinear programming problem. In general, practitioners have found it hard to solve even a problem for a system with a small number of planning periods and hydroelectric plants using current nonlinear programming techniques. This is due, in large measure, to complex nonlinearities of the power generating functions and a large number of linear equality constraints involved in the model. Furthermore, most reservoirs systems in arid regions have periods of low water level which often results in an empty feasible region adding considerable difficulties to the operational feasibilities of the solutions. In this paper, we provide a general formulation of the water resource allocation problem with explicit engineering details generally omitted or oversimplified in the published literature, and investigate several solution procedures for their applicabilities, and we develop an efficient algorithmic framework exploiting the general water resource system special network structure to solve the linear equality constraints. Practical feasibility of this approach is demonstrated in several applications with a real water resource system.

The morphology of a saline groundwater body: Its investigation, description and possible explanation

In many countries knowledge concerning the occurrence and behaviour of saline groundwaters is becoming even more vital as water resource and waste disposal projects become more sophisticated. This paper outlines the approach adopted in, and the result obtained from, a study of saline water occurrence in an important United Kingdom aquifer. Saline groundwater, of concentration up to at least 100 g l −1 Cl −, occurs as a layer of variable thickness below fresh groundwater in the Permo-Triassic sandstones of the Lower Mersey Basin of northwestern England. As part of a general water resources study, a detailed investigation of the morphology of the saline water body was undertaken using modern and historical chemical data, surface geophysics, borehole geophysics, open hole depth sampling, and borehole core porewater analysis. It was found that Cl − concentrations at all sites show a pattern of steady increase to depths of at least 320 m. The surface of the saline water body has a considerable topographic variation. Saline water occurs at highest elevations below the roughly east—west trending Mersey Valley where it approaches ground level, but declines in elevation both to the north and south: In the north the saline “interface” meets the rising base of the sandstone sequence at a depth of around 280 m. Evidence from chemical and viscous flow analogue studies suggests that this ridged topography can be explained in terms of flushing and regional upconing in response to low groundwater heads in the Mersey Valley.

State Ground‐Water Protection Programs — Inadequatea

ABSTRACTThe primary reason State ground‐water protection programs are inadequate is that the resource is misunderstood, surrounded by misconceptions and, due to its occurrence, is “out of sight and out of mind.” To most people, ground water is a very elusive and somewhat magical resource, whose significance in the over‐all picture of water resources has not been realized by those who have the power and authority to rectify the present state of affairs. The need for adequate protective legislation and sufficient financial and manpower resources commitment is even more difficult to justify because there has not, to date, been a citizenry outcry for such measures.To ascertain the status of current State ground‐water protection programs, a survey of State legislation concerning ground water was undertaken; additionally, a questionnaire was sent to the agency in each State responsible for administration of ground‐water protection programs. The results of this survey indicate that most States have broad authority over ground‐water resources through general water resources legislation, but the majority do not have specific ground‐water protective legislation. In many cases, the broad legislative authority is inadequate or, if legislation is adequate, implementation of legislative mandates is not sufficient to provide adequate protection. Lack of ground‐water quality and quantity data is severe to the point that many agencies do not have a realistic characterization or identification of the ground‐water resources they are to protect.

Future role of desalting for water quality improvement - Colorado River Basin, U.S.A.

Up to the present time, the development of desalting technology has been mainly directed at water supply augmentation. In view of Federal and State legislation in the U.S.A. to support water pollution control and water quality improvement, along with advances in membrane desalting processes, an expanded new role for desalting is discussed. Potential desalting applications now under study by the Bureau of Reclamation's “Colorado River Water Quality Improvement Program” are examined along with general constraints, cost-effective criteria, planning strategies, and water resources impacts. Specific desalting sites and time frames are briefly addressed from a planning viewpoint generally limited to the upper region of the Colorado River Basin. Estimates of plant capacities, general feedwater conditions, costs, and various types of processes under planning investigation are provided. The paper suggests key areas of membrane desalting research needs related to salinity control. Finally, this planning overview concludes that the economic differences between conventional salinity control techniques and desalting may be narrowing.

WATER RESOURCES AND SOCIAL CHOICES1

ABSTRACT The problem of water resources management can be viewed as one requiring the existence and application of some type of “collective decision” mechanism. Currently, the general water resource decision problem is solved using an “individual decision” format without explicit consideration of the dominant social decision system. This paper demonstrates the need for blending technical planning activities with organized societal processes and then proposes a specific public decision framework to satisfy this requirement. The key element in this planning framework is a generalized “bargaining arena” which serves to link technical activities with the social system. Using this bargaining device we can (1) specify policy at a local level, (2) incorporate “social decision” rules into the planning process, and (3) provide local access to the decision process. A simple case of regional water quality management is used to describe the application of this planning procedure and to offer encouragement for successful use in more complex real‐world cases.

Spray Irrigation and the Water Resources Act, 1963

The Water Resources Act (I963) in England and Wales has brought about some valuable innovations in the field of water-resource management. Among them the charging scheme is particularly challenging, for it attempts to assess the effect of each abstraction upon the general water resource and upon other legitimate users. The purpose of this article is to assess the charging scheme as a management tool, and to appraise in particular the manner in which it may be used to guide decisions in the use of water for spray irrigation. The major findings of the study point to certain difficulties in managing the present and future demands for spray irrigation. The policy adopted by most river authorities to require future irrigators to provide private sources of supply appears highly satisfactory, though substantial demands are still made by direct abstractors operating under prescriptive licences of right. This latter group, whose demands must be met (at least in moderately dry years), may seek augmentation of river flow to safeguard their licences. It is shown that their perception of alternative management techniques is not readily influenced either by the charging scheme or by institutional guides. It is also shown that the imposition of the charging scheme still favours the direct abstractor over the private source irrigator, though in both cases the cost of water bears little relation to its true value except for low-value crops such as grass. It is suggested that predictions for irrigation demand may be overestimated as a result of the charging scheme, though it is also contended that the Act does not provide sufficient guides to help the irrigator search for alternative means to improve crop yield. GEOGRAPHERS are showing an increasing interest in the means of allocating scarce resources, particularly in the case of conflicting multiple use of an important natural resource. Although this field has traditionally belonged to the engineer and economist, geographers are now realizing that they can make a significant contribution to the efficient management of resources (G. F. White, 1962; I. Burton and R. W. Kates, 1965; White, in prep.). A combined approach has reached its most sophisticated form in the field of water-resources management, particularly in the United States (National Academy of Sciences, National Research Council, 1966, 1968). One effect of this wider approach to the management of resources has been a change in the meaning of conservation. The old concept of preservation or protection from use has been replaced by a much more positive and dynamic attitude which emphasizes efficient multiplepurpose management. Each category of demand upon a scarce resource must be made as efficient as possible so that maximum benefits are derived with the minimum of wastage. To achieve this, each particular user is encouraged to consider various methods of utilization, each of which should provide the same benefits though utilizing the resource to different extents. This may lead to a change in the management of the resource, which, though it may involve additional private cost to the user, results in important social benefits. There are considerable advantages in evaluating the direct and indirect consequences of different uses of resources, both upon the individual and upon the community in space and time, and in relating the costs of the use of resources more directly to those who benefit. Examples include controlling development in flood hazard areas to reduce flood damage (Kates, 1962), improving effluent