Application of a Decision Making Analysis to Evaluate Direct Recharging of an Unconfined Aquifer in Jordan

This case study describes the application of the Freeze et al. (1991) decision analysis approach to design an artificial recharge program for a basin, known in Jordan as Yarmouk Basin. This approach of design was selected because it suits projects in which the hydrogeological environment plays an important role; and because the approach to design involves quantifying benefits, costs, and risks for recharge alternatives under consideration. Risk, which is added here, is defined as the expected costs of failure. It reflects both performance uncertainties and failure costs. Probability of failure to attain a prescribed drawdown at each of the compliance points was estimated by coupling a parameter uncertainty model with a groundwater flow simulation model and a reliability model. The simulations were based on an ensemble of thirty realizations of hydraulic conductivity field which were generated by a parameter uncertainty model after assuming the hydraulic conductivity field log-normally distributed spatially. Finally, the decision between alternatives was made by a decision making model which considers both the costs and risks. Decision variables consist of the number, location, and recharge rate of the injection wells. The results showed how the preferred design alternative depends upon the hydrogeological, and economic considerations. Moreover, the preferred alternative under the adopted criteria for recharge was found less sensitive to the cost of failure, but highly dependent upon the total cost of the system. Copyright Kluwer Academic Publishers 1999