Decision support for optimal regional groundwater management strategy modification

AN inleraclive.decis io~.support progra~ is presented ~or . th~ rapid mocllficatlon of optimal regional multlobJcdlve groundwater planning strategies. This capabi lity is important for water managers seeking to select the most satisfactory groundwater management strategies for their areas. The program guides decision maker(s) in refining numerically optimal regional strategies into strategies that may be socially or politically more acceptable. Strategy refinements are made by informed modification of constraining conditions on regional objectives or local variables. Appli~ation is illustrated by . mOdifying a bicriterion, sustained groundwater Withdrawal strategy for minimizing the cost of meeting regional water demand on the Arkansas Grand Prairie, an important irrigated area. The strategy was developed using a model in which the finite difference form of the two-dimensional groundwater flow equation is embedded in an optimization process. Results from the formal optimization process are submitted to the interactive program for evaluation and modification. This algorithm applies the constraint method and constrained derivatives to develop noninferior solutions and tradeoff fu~cti~ns and to determine the innuence on the regional objectives caused by repeated changes in several local decision variables. Allhough its application is demonstrated with only a single optimization model. the interactive program can be utilized to modify optimal strategies resulting from other models as well.