YIELD MODEL FOR SCREENING SURFACE-WATER AND GROUNDWATER DEVELOPMENT

An optimization model is developed for selecting between candidate sur face-water reservoirs and ground-water development. The model may be u sed to perform a preliminary screening of alternatives for water-suppl y development, and to identify storage capacities at reservoir sites, as well as aquifer pumping at candidate locations. A hybrid simulation -optimization strategy is used to consider monthly operation of the re servoir and aquifer system using historical or synthetic hydrologic da ta. A modified sequent peak algorithm is used for reservoir sizing, an d a unit response matrix approach is used to model the ground-water su bsystem. A target aggregate firm yield from the surface water-ground w ater system may be specified. Decisions on the failure of firm yield a t each reservoir site during a critical period for streamflow, with a corresponding increase in ground-water pumping such that the system fi rm yield is maintained are considered. Example applications with data from the Jordan River basin in Utah demonstrate the utility of the mod el relative to a disjunctive analysis of surface water-ground water de velopment.