OPPORTUNITIES FOR MAXIMIZING POTENTIAL OF GROUNDWATER AVAILABILITY MODELING

The Texas Water Development Board (TWDB) has provided the State of Texas and hydrogeologists working therein a powerful tool in the Groundwater Availability Models (GAMs). Now that many of the GAMs are being used the question remains as to how we can optimize the use of these models for their continued development. GAM models are currently used by agencies and consultants to estimate quantities of water for long-term and short-term planning, rule development, and other uses. The results of these analyses are accompanied by uncertainty in the predictive capability of the model. Recent developments using optimization techniques have provided modelers with tools to quantify the uncertainty and parameter sensitivity of the models. These tools, both commercial and public domain, are available to modelers and can be used to guide further model development in order to decrease the levels of uncertainty in the model and increase the usefulness as predictive tools. Two case studies involving both water resources and contaminant transport are examined to illustrate the viability of guiding model development through the use of optimization tools. The first involves use of the Richter and Dutton (1990) model for determination of sensitivities and uncertainties. The second involves the use of a smaller-scale model for determination of groundwater extraction network optimal plume clean up. Both of these cases showed the usefulness of optimization techniques in guidance of future decision-making.