Integrated Management of Wadi aquifers Using Mathematical Modelling and Optimization Approach

Abstract

Groundwater represents a vital source of fresh water supply in many parts of Sudan. Recently, there is a growing concern about this important resource and its development for combating drought and overcoming the erratic nature of rainfall over large areas of the country. In order to develop appropriate management policies of groundwater abstraction, there is a need for improved understanding of aquifer behavior and its interactions with other hydrological phenomena. Among the important tools used to achieve the above goals are mathematical modeling and optimization techniques. In this study, an integrated mathematical modelling and optimization approach was applied to an important aquifer in Eastern Sudan, which is primarily recharged from Wadi bed transmission losses. The integrated model consists of two sub models; a numerical sub model for simulating the aquifer behavior and a sub model that relates the groundwater recharge to the Wadi flow. The combined model is an integrated parameter optimization model. Out of a total of four years of monthly water level data at five observation wells and monthly Wadi flows, three years were used for model calibration and the remaining year was used for model verification. The integrated model is then used to investigate the future consequences of a number of pumping scenarios from the aquifer to be used for town water supply conjunctively with the other available water resources. Accordingly, the optimum operating policy that will guide pumping from the aquifer up to 2010 is recommended.