WATER-QUALITY MODELING FOR ENVIRONMENTAL-MANAGEMENT - LESSONS FROM THE POLICY SCIENCES

Models are used in many policy arenas to predict the future consequenc es of current decisions. A model is typically viewed as a rational, ob jective means of processing complex information to predict future cond itions. With respect to socioeconomic modeling, policy scientists have found that models frequently do not live up to these promises - they often incorporate the modelers' biases, are difficult for decision mak ers to use, and do a poor job of point predictions. While awareness of these characteristics of socioeconomic models has increased, less att ention has been paid to such factors in environmental modeling. This p aper explores the implications of policy scientists' observations abou t socioeconomic models for the use of water quality models in environm ental decision making. For example, the relatively simple task of mode ling for an estuarine waste load allocation decision incorporates judg ment in model choice, calibration, and use. More complex watershed mod els involve even more choices that have implications for decision maki ng. Thus, environmental models are not strictly technical inputs to th e policy process. Model users, regulators, and the public should be aw are of the judgments and uncertainties involved in surface water quali ty modeling so that model results are used appropriately in the decisi on-making process.