Joint management of surface and ground water supplies

A management model is developed to determine optimal mater allocation polic ies for hydraulically connected time-variant surface and ground water suppl ies in a hypothetical system. The system involves a multipurpose reservoir, a hydraulically connected stream and aquifer, agricultural plots, water su pply and observation wells, and an artificial recharge zone. The model mini mizes deviations from a set of rule curves defined for storage in the reser voir and along the stream course, so as to consider possibilities for stora ge of excess water in wet periods and its distribution in subsequent dry pe riods. The hypothetical system is divided into components which are subsequ ently integrated using numerically generated response functions that relate the systemis behavior to various system excitations. The management model is formulated and solved for monthly time steps, which include both dry and wet conditions, to determine reservoir release, pumpage rate from supply w ells, artificial recharge rate, water diversion from reservoir and stream t o the demand area, and storage both in the reservoir and along the stream c ourse at an optimal level in each time step over a six-month planning horiz on. Furthermore, sensitivity analysis of the management plan with respect t o potential use of ground water supplies is performed to analyze the latter 's impact on operating policies.