Numerical-Simulation Based Multiobjective Optimization of Agricultural Land-Use with Uncertainty

Land-use management has a direct impact on the environment and the ecosystem. Optimal agricultural land-use management is a Pareto-optimal compromise between conflicting technical, environmental and economical considerations. This paper describes multi-objective optimization of agricultural land use-management using TABU search method. For each trial scenario, multiple objective functions are constructed based on coupled simulation of AnnAGNPS watershed model, which computes the water, sediment and agrochemical loadings into streams, and CCHE1D channel network model, which simulates one-dimensional unsteady channel network flow on erodible bed with non-equilibrium transport of non-uniform sediments, transport/fate of contaminants, and water quality. To account for parameter uncertainties and uncertainties in numerical model results, the combined objective function is calculated using fuzzy computation based on alpha-cut techniques to obtain a membership function which yields not only a crisp value but also a range of variation. The proposed approach is tested using a hypothetical land-use management study for the Goodwin Creek experimental watershed.