OPERATIONS RESEARCH STUDY OF WATER RESOURCES

Applications of systems methodology to water problems of the Tucson basin are summarized. Natural recharge is estimated by means of a discrete convolution relation in which the unit impulse response of an aquifer is derived from basic hydro-dynamic laws. A temporal model of sequences of wet and dry periods during the summer thunderstorm season is based on a multiple linear regression equation that relates total rainfall amount during the wet period to the duration of the wet period and volume of peak rainfall. A spatial model predicts point rainfall frequency of maximal and minimal amounts of thunderstorm rainfall. A static management model allocates Tucson groundwater, Avra Valley water, Colorado River water, and reclaimed waste water to municipal, industrial, and agricultural users within a pricing framework. For a range of pricing policies the model clearly demonstrates the opportunity costs to the community by use of higher-priced water supplies such as Colorado River water in lieu of Tucson groundwater. The role of worth of data studies in relation to data analysis, model building and management studies is also introduced.     

PART I: METHODOLOGY AND PROBLEMS IN AN URBANIZED ARID ENVIRONMENT1

The methodology of operations research is judged in relation to its utility to water resource management in an urbanized arid environment and to the study of worth of data for such management. Conditions for existence of a managerial problem are reviewed as is the multilevel structure of the decision process, including decisions on social goals for Western water use. Worth of data can only be judged in relation to a particular use to meet a social or managerial objective. The role of data uncertainty on the decision process is reviewed in the light of past water decisions and present and future problems.