Multi-Objective Management of Heterogeneous Coastal Aquifers.(Dept.C)

Abstract

A nonlinear optimization problem based on both single and multiple objective management functions for sustainable utilization of heterogeneous coastal aquifers was formulated and solved. The sharp interface approach was assumed within this work. Finite Element Method (FEM) was applied on Sirack's formulation to simulate the hydraulic response of the steady slate heterogeneous aquifer under different objectives. The LU-decomposition method was exploited to inverse the conductance matrix, that enhanced the computation time. The constraint technique was used to simplify, without any approximation, the multi objective management problem to single objective management problem. Genetic Algorithm (GA) was used to solve the nonlinear optimization problem. A Fortran program was written and verified against a problem that has an analytical solution. A hypothetical example was solved for one and three objective functions. These func tions are maximum magnitude of extracted freshwater, minimum drop in water table level, and minimum increment in volume of intruded saltwater.