A Systems Approach to Management of the Hanford Ground‐Water Basina

Abstract

ABSTRACTMathematical models for simulating ground water and radionuclide movement as a function of time and space are being developed. In addition to the models, a man‐machine interactive computer system is under development for use in model applications. In total, the research and development program will produce a management and engineering tool for use in analysis, decisions and policy formulations relative to management of ground‐water systems.The system is separated into sequential or parallel components that can be modeled independently of each other. This results in maximum capability to simulate all combinations of situations that may be encountered and in ease of modifying or refining the models independently without having to reformulate the entire system. The system is composed of three major categories of models: (1) data models; (2) hydraulic models; and (3) water quality (transport) models. Data models calculate input characteristics required for operation of the hydraulic and water quality models from a minimum of field measurements. The Transmissivity Iterative Routine for calculating transmissivity distributions and the Sorption Transmissivity Routine for calculating sorption coefficient distributions are two types of data models. The hydraulic models predict the flow of ground water in saturated and un‐saturated soils. The Partially‐Saturated Transient Model, which describes unsaturated, transient flow, and the Variable Thickness Transient Model, which describes saturated, transient flow, are included in this category. The water quality models predict the movement of the waste through the subsurface soils. The Macro‐ion Transport Model, which describes macro‐ion movement, and the Micro‐ion Transport Model, which describes micro‐ion movement, are included in this category. The assumptions used in developing the system of models, justification of these assumptions, the interrelationship of each of the models, and the intended application of the entire system are presented.The man‐machine interactive computer system provides an efficient means for the engineer to interact in the problem solving functions using the previously discussed models. The system allows the engineer to rapidly scan a large number of alternatives and use his experience in rapidly converging on a solution. The components of the computer system and their functions are described. Examples showing how the computer system is being used with models that have been developed are presented.