GEOGRAPHIC INFORMATION SYSTEMS AS A TOOL IN WATER USE DATA MANAGEMENT1

ABSTRACT: The temporal and locational attributes of water use data are ideally suited for analysis using a geographic information system (GIS) approach. A GIS combines spatial database management, statistical analysis, and cartographic modelling capabilities within a computer hardware and software configuration. Texas water use data for selected categories in 1980 and 1986 were analyzed using ARC/INFO to demonstrate the utility of GIS for water resource information management. Examples of data analysis and display are presented to illustrate the effectiveness of cartographic representations to communicate water use data.     

UTILIZATION OF REMOTE SENSING IN RIVER BASIN STUDIES1

ABSTRACT: Remote sensing techniques have the potential for significantly reducing the level of effort in a river basin water quality study. An immediate requirement exists, however, for the formulation of the proper methodology for the application of remote sensing to this problem area. A general methodology is proposed for conduct of river basin water quality studies. The primary advantage offered by the proposed methodology is a technique for rapid evaluation of the water quality conditions of a river basin. Remote sensing techniques are a fundamental part of the methodology. The proposed methodology consists of two phases. Phase I deals with the study of the water resource characteristics of the basin as a system and identification of “critical areas.” Phase II of the methodology involves the detailed study of the critical areas by means of computerized water quality simulation models.     

AN INTERACTWE MODELING ENVIRONMENT FOR NON-POINT SOURCE POLLUTION CONTROL1

ABSTRACT: Non-point source pollution cuntinues to be an important environmental and water quality management problem. For the moat part, analysis of non-point source pollution in watersheds has depended on the use of distributed models to identify potential problem areas and to assess the effectiveness of alternative management practices. To effectively use these models for watershed water quality management, users depend on integrated geographic information systems (GIS)-based interfaces for input/output data management. However, existing interfaces are ad-hoc and the utility of GIS is limited to organization of input data and display of output data. A highly interactive water quality modeling interface that utilizes the functional components and analytical capability of GIS is highly desirable. This paper describes the tight coupling of the Agricultural Non-point Source (AGNPS) water quality model and ARC/INFO GIS software to provide an interactive hybrid modeling environment for evaluation of non-point source pollution in a watershed. The modeling environment is designed to generate AGNPS input parameters from user-specified GIS coverages, create AGNPS input data files, control AGNPS model simulations, and extract and organize AGNPS model output data for display. An example application involving the estimation of pesticide loading in a southern Iowa agricultural watershed demonstrates the capability of the modeling environment. Compared with traditional methods of watershed water quality modeling using the AGNPS model or other ad-hoc interfaces between a distributed model and GIS, the interactive modeling environment system is efficient and significantly reduces the task of watershed analysis using tightly coupled GIS databases and distributed models.     

A CATALYST FOR REGIONALIZATION OF RURAL WATER SYSTEMS1

ABSTRACT: The National Regulatory Research Institute has recommended the merger of small rural water districts in the United States. Success at bringing about merger of these districts, which contain fewer than 3,500 customers, has been highly limited. The subject of this paper is a demonstration project that may act as a catalyst to achieve the desired goal of regionalization. A computerized hydraulic data management program (CHDMP) was developed for a case study in Nelson County, Kentucky. University professors, graduate students, and two water utilities’ staffs cooperated in network analysis employing computer hardware and software. The utilities’ staffs were taught the science and technology of hydraulic model preparation, simulation, and analysis for the case study distribution systems. As an integrated system, the model contained 294 pipes, 234 nodes, six pumps, and 11 tanks. Each utility's problem areas were identified and some of the individual and mutual benefits of hydraulic planning were illustrated. A dialogue resulted between the managers. Each manager described his goals and agreed that, although political merger was not feasible at the present time, future economic factors could be a definite influence in reversing that decision.     

Perception of drinking water in the Quebec City region (Canada): the influence of water quality and consumer location in the distribution system

The purpose of every water utility is to provide consumers with drinking water that is aesthetically acceptable and presents no risk to public health. Several studies have been carried out to analyze people's perception and attitude about the drinking water coming from their water distribution systems. The goal of the present study is to investigate the influence of water quality and the geographic location of consumers within a distribution system on consumer perception of tap water. The study is based on the data obtained from two surveys carried out in municipalities of the Quebec City area (Canada). Three perception variables were used to study consumer perception: general satisfaction, taste satisfaction and risk perception. Data analysis based on logistic regression indicates that water quality variations and geographic location in the distribution system have a significant impact on the consumer perception. This impact appears to be strongly associated with residual chlorine levels. The study also confirms the importance of socio-economic characteristics of consumers on their perception of drinking water quality.     

DATA REQUIREMENTS OF A WATER QUALITY MANAGEMENT PROGRAM1

ABSTRACT: Routine data collection currently consumes a large amount of the total resources devoted to water quality management. All too often data collection becomes an end in itself, with little thought given to the purpose of the data collection. The problem generally stems from a lack of proper routine surveillance system design and a failure on the part of the designers to initially identify the data needs of the management program. This study attempts, in a general way, to delineate the data needs of a water quality management program. This first required an identification of the activities involved in water quality management. The activities were then discussed in terms of the types of information needed to successfully complete their assigned tasks. Several detailed examples are given. The results of the discussion are summarized and several strategies are proposed to relate the results to surveillance system design.     

EVALUATION OF HYDROLOGIC MODELING TECHNIQUES FOR FOREST LAND MANAGEMENT PLANNING1

ABSTRACT: A growing concern for environmental quality paralleled with increasing demands on our forest resources has prompted the Washington State Department of Natural Resources to evaluate simulation modeling as a technique for analyzing management decisions in terms of their environmental effects. The evaluation focused on a system of integrated models developed at the University of Washington which simulate processes and activities within the forest ecosystem. A major part of the system is a hydrologic model which predicts changes in discharge, stream temperature, and concentrations of suspended sediment and dissolved oxygen based on information generated by other models representing intensive management practices. The evaluation consisted of applying the system to a 72,000 acre tract of forest land, validating the models with two years of discharge and water quality data from a 93,000 acre watershed, and determining the pertinence of hydrologic modeling for management purposes. Results show several potential uses of hydrologic modeling for forest management planning, especially for analyzing the effects of timber harvesting strategies on water quality.     

SIMULATION OF INTEGRATED SURFACE WATER AND GROUND WATER SYSTEMS - MODEL FORMULATION1

ABSTRACT: The unique characteristics of the hydrogeologic system of south Florida (flat topography, sandy soils, high water table, and highly developed canal system) cause significant interactions between ground water and surface water systems. Interaction processes involve infiltration, evapotranspiration (ET), runoff, and exchange of flow (seepage) between streams and aquifers. These interaction processes cannot be accurately simulated by either a surface water model or a ground water model alone because surface water models generally oversimplify ground water movement and ground water models generally oversimplify surface water movement. Estimates of the many components of flow between surface water and ground water (such as recharge and ET) made by the two types of models are often inconsistent. The inconsistencies are the result of differences in the calibration components and the model structures, and can affect the confidence level of the model application. In order to improve model results, a framework for developing a model which integrates a surface water model and a ground water model is presented. Dade County, Florida, is used as an example in developing the concepts of the integrated model. The conceptual model is based on the need to evaluate water supply management options involving the conjunctive use of surface water and groundwater, as well as the evaluation of the impacts of proposed wellfields. The mathematical structure of the integrated model is based on the South Florida Water Management Model (SFWMM) (MacVicar et al., 1984) and A Modular Three-Dimensional Finite-Difference Groundwater Flow Model (MODFLOW) (McDonald and Harbaugh, 1988).     

MATHEMATICAL MODELING OF GULF COAST ESTUARIES1

The environmental pollution problems prevalent in gulf coast estuaries are a cause of great concern to those in water quality management. This paper outlines the dominant characteristics which affect the properties of these estuaries including geography, tide and current effects, wind effects, salinity and density regime, nature and level of waste discharge, low inflow levels, dredging effects and present quality levels. Two basic levels of analytical modeling which are useful in water quality management are presented. The first is a relatively crude completely mixed estuarine model which permits economical evaluation of varying parameters. The second is a very general steady state model which permits analysis of stratified systems. The ESTPOL computer language designed to simplify the use of the steady state model is described. The practical use of the analytical models as management tools for the solution of Texas Estuarine quality problems is demonstrated.     

APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS TO GROUNDWATER MONITORING NETWORK DESIGN1

ABSTRACT: Effective monitoring configurations for contaminant detection in groundwater can be designed by analyzing the spatial relationships between candidate sampling sites and aquifer zones susceptible to contamination. Examples of such zones are the domain underlying the contaminant source, zones of probable contaminant migration, and areas occupied by water supply wells. Geographic information systems (GIS) are well-suited to performing key groundwater monitoring network design tasks, such as calculating values for distance variables which quantify the proximity of candidate sites to zones of high pollution susceptibility, and utilizing these variables to quantify relative monitoring value throughout a model domain. Through a case study application, this paper outlines the utility of GIS for detection-based groundwater quality monitoring network design. The results suggest that GIS capabilities for analyzing spatially referenced data can enhance the field-applicability of established methodologies for groundwater monitoring network design.     

ECONOMIC APPRAISAL OF A GROUND WATER DEVELOPMENT PROJECT1

A ground water development project in the northern part of Thailand was appraised by means of benefit-cost analysis. This is the first project in Thailand to develop ground water for irrigation purposes and it is also the first project which made use of an underground PVC pipe water distribution system. Results indicate that the project is economically feasible. In comparing different water distribution systems, it is also found that distribution by means of underground PVC pipes is more economical compared to an open ditch system if the life of the latter is relatively short and the rates of inflation are high.     

SIMULATION – A TOOL FOR WATER RESOURCE MANAGEMENT1

ABSTRACT: Proper economic evaluation of alternative plans will maximize the utility achieved from the resources available for water resource management. A knowledge of the frequency of occurrence of the events under study is necessary to fully utilize the advantages of economic evaluation in planning. Frequency information is widely used in flood control and water supply, but relatively unknown in water quality planning. A continuous, dynamic hydrologic and water quality model is presented to develop frequency curves for various water quality criteria. Results from the Denver Regional Water Quality Management Study are discussed as an example of the use of frequency analysis for economic evaluation of water quality management.     

EMPHASIS ON DISTRIBUTION: STRATEGIES FOR SMALL SCALE WATER RESOURCES DEVELOPMENT IN THAILAND1

This paper discusses strategies for the development of water resources, emphasizing the delivery of reliable water supplies, for both domestic and production purposes, to every village and to every farmer. This necessitates a shift of emphasis from the construction of large storage reservoirs to the construction, operation, and maintenance of water distribution systems capable of reaching the largest number of farms, and a shift from projects that benefit the few, to projects that benefit the many. Water distribution in this context takes on three interrelated meanings: a geographical meaning, a technical meaning, and an economic meaning. The geographical meaning focuses on the spatial distribution of the recipient population as a key to identifying the proper distribution of water projects in physical space. The technical meaning relates to the physical distribution of water through canal systems to the farmers' fields. The economic meaning refers to the equitable distribution of benefits from water projects. The paper provides an illustration of the need for an emphasis on distribution, using the state of development of water resources in northeast Thailand as an example, with a proposed program for the further development of these resources. The northeast, the poorest region in the country, has been recognized by the Government of Thailand as a priority area for accelerated regional development efforts.     

REGULATORY WATER QUALITY MONITORING: A SYSTEMS PERSPECTIVE1

ABSTRACT: Regulatory water quality monitoring has evolved to the point where it is a rather complex system encompassing many monitoring purposes and involving many monitoring activities. Lack of a system's perspective of regulatory monitoring hinders the development of effective and efficient monitoring programs to support water quality management. In this paper the regulatory water quality monitoring system is examined in a total systems context. The purposes of regulatory monitoring are reviewed and categorized according to their legal evolution. The activities of regulatory monitoring are categorized and organized into a system which follows the flow of information through the monitoring program. The monitoring purposes and activities are combined to form a monitoring system matrix - a framework within which the total regulatory water quality monitoring system is defined. The matrix, by defining the regulatory monitoring system and clarifying many interactions within the system, provides a basis upon which a more thorough approach to managing, evaluating, and eventually optimizing regulatory monitoring can be developed.     

AN APPLICATION OF INVESTMENT TIMING ANALYSIS: DUAL WATER SYSTEMS1

ABSTRACT: A general methodology to study the economics of dual water systems (defined here as a separate distribution system for untreated low quality local surface Water for outdoor municipal water supply) is summarized and the application of the method to a rapidly growing city is presented. In the first step, a cost-benefit criterion for evaluating dual systems is developed. The criterion is then extended to a dynamic case where the population to be served increases with time and where the dual system is allowed to expand. The optimal investment time to introduce the dual water supply project is obtained by maximizing social welfare. The model is applied to the city of West Jordan, Utah, where a dual system is currently being proposed. Model results indicate that for the city as a whole dual supply is not economically feasible. However, when the model is applied to a part of the city, it is found feasible and the optimal time to initiate the project would be in the year 1989.     

WATER QUALITY PREDICTION WITHIN AN INTERBASIN TRANSFER SYSTEM1

ABSTRACT A methodology for predicting the spatial and temporal levels of conservative water quality constituents within a multibasin water resource system is presented. Dissolved solids, sulfates, and chlorides are the constituents used during this investigation; however, any other conservative ion or mineral can be incorporated into the simulation model. The methodology is tested on the proposed Texas Water System. The water quality model, QNET-I, utilizes monthly canal and river flows and reservoir storage levels calculated by the Texas Water Development Board's systems simulation model. Discharge-concentration relationships are developed for each source of water in the system, including significant waste-water discharges. Reservoirs in the system are assumed to be completely mixed with respect to conservative constituents. A mass balance analysis is performed for each node and each month during the simulation period. The output from the water quality simulation is a table of the concentrations of the conservative water quality constituents at each demand point in the system and in each reservoir and canal for every month the system is in operation. The desired quality of the water at the demand locations is used to determine the economic utility of transporting and mixing water from various sources.     

ELEMENTS OF A WATER QUALITY INFORMATION SYSTEM FOR THE STATE OF ILLINOIS1

ABSTRACT: A great deal of information can be derived from study of standard stream monitoring data, if these are properly ordered and organized. This information may then be used to make decisions about water quality management. Among critical information items are evaluation of performance to standards, determination of seasonality and time-trends of water quality conditions, and estimation of the effects on water quality to be expected from load reductions or standards modifications. Additional information on the magnitude of individual pollution sources is also critical to water quality management. Each of these items can be derived within the water quality information system which is currently under development for the State of Illinois.     

FIELD SCALE MULTIOBJECTIVE DECISION MAKING: A CASE STUDY FROM WESTERN IOWA1

ABSTRACT: Water quality issues in agriculture are growing in importance. A common theme is the provision of better information to decision makers. This study reports the trial of a prototype decision support system by the U.S. Department of Agriculture Natural Resources Conservation Service and the Agricultural Research Service in the NRCS Harrison County Field Office in 1998. Observed data collected at the Deep Loess Research Station (DLRS) near Treynor, Iowa, were extrapolated using a modified GLEAMS field scale simulation model that included a nitrogen leaching component and a crop growth component. An accounting tool was used to convert crop yield estimates into crop budgets. A model interface was built to specify the climate, soil, and topography of the field, as well as the management scenarios for the alternative management systems. For the Deep Loess Hills area of Harrison County, a total of six soil and slope groups, with 66 total combinations of management practices forming management systems, were defined and simulated based on previously calibrated data from DLRS. A multi‐objective decision support system, the Water Quality Decision Support System, or WQDSS, was used to examine the tradeoffs in a comprehensive set of variables affected by alternative management systems with farmers in Harrison County. The study concluded that a multiobjective decision support system should be developed to support conservation planning by the NRCS. Currently, a larger scale effort to improve water quality decision making is underway.     

THE CONCEPT OF HYDROLOGIC LANDSCAPES1

ABSTRACT: Hydrologic landscapes are multiples or variations of fundamental hydrologic landscape units. A fundamental hydrologic landscape unit is defined on the basis of land‐surface form, geology, and climate. The basic land‐surface form of a fundamental hydrologic landscape unit is an upland separated from a lowland by an intervening steeper slope. Fundamental hydrologic landscape units have a complete hydrologic system consisting of surface runoff, ground‐water flow, and interaction with atmospheric water. By describing actual landscapes in terms of land‐surface slope, hydraulic properties of soils and geologic framework, and the difference between precipitation and evapotranspiration, the hydrologic system of actual landscapes can be conceptualized in a uniform way. This conceptual framework can then be the foundation for design of studies and data networks, syntheses of information on local to national scales, and comparison of process research across small study units in a variety of settings. The Crow Wing River watershed in central Minnesota is used as an example of evaluating stream discharge in the context of hydrologic landscapes. Lake‐research watersheds in Wisconsin, Minnesota, North Dakota, and Nebraska are used as an example of using the hydrologic‐land‐scapes concept to evaluate the effect of ground water on the degree of mineralization and major‐ion chemistry of lakes that lie within ground‐water flow systems.     

DETERMINING THE SOURCE OF STREAM CONTAMINATION IN A KARST‐WATER SYSTEM,SOUTHWEST VIRGINIA,USA1

ABSTRACT: Karst terrane provides a linkage between surface water and ground water regimes by means of caves, sinkholes and swallets, and sinking streams, and facilitates the inter‐watershed transfer of water and contaminants through these subsurface systems. The goal of this study was to develop procedures to identify the sources of degradation of a creek situated in a complex karst‐water system. The study approach consisted of using dye tracing technique to determine subsurface flow paths through the karst system, a water‐sampling network to identify and characterize pollution sources within the surface watershed and subsurface flow regime, and evaluation of analytical data for several water quality parameters. The results of this study provide an interesting perspective of water and contaminant movement in karst‐water systems and pinpoint the sources of stream contamination for a case study site in southwest Virginia where two springs supply water to a contaminated freshwater stream.