MODELING FOR WATER-QUALITY DECISIONS - UNCERTAINTY AND SUBJECTIVITY IN INFORMATION, IN OBJECTIVES, AND IN MODEL STRUCTURE

Quantification and reduction of uncertainty associated to decision mak ing is one of the primary functions of modeling and monitoring targete d to assist decision making in reservoir, river, and lake water qualit y management. In many practical activities such as environmental impac t assessment, the inference is bound to be based primarily on subjecti ve, expert judgments, supported by empirical data and models. A bulk o f analytical approaches is presently available for modeling purposes. The paper discusses selected decision analytic approaches to the handl ing of uncertainty and subjectivity associated to information availabl e, as a decision criterion, and as a component influencing the model s tructure. Computational solutions based on experience on seven case st udies are reviewed.