Reevaluating FMOLP Decision Variable Coefficients Using the SWAT Results for the Optimization of Sustainable Agricultural Land Use in Small Watershed

The inappropriate use of agricultural land has caused several environmental and socio-economic problems. Fuzzy multiple objectives linear programming (FMOLP) is a mathematical technique that can be effective in land use planning. It requires decision variable coefficients (DVCs) to formulate the problem model covering all environmental and socio-economic aspects. The solution from a formulated FMOLP model provides optimal land use proportion and then the proportion is relocated t o produce the land use planning map. The map is then transferred to the soil and water assessment tools (SWAT) for assessing the impacts. The SWAT results give out a value which differs from the initial DVCs in the comparable aspects. This difference indicates that the initial DVCs were not realistic for the selected watershed and the land use planning map were not optimal. This study attempts to reevaluate DVCs in the FMOLP model by designing a method of sustainable agricultural land-use planning which makes use of the outputted results from the SWAT model. The results in terms of soil loss, crop water consumption, crop yields and net profit are simulated by SWAT and then replace to the DVC’s value. This procedure will be repeated until a small difference between SWAT results and DVC’s values are obtained. The findings of this study show that the final land use map achieves a higher target value than the map that was constructed after the initial phase of testing in all of objective. It is hoped the outcomes of this loop back process can be linked to the optimizing technique, so that environmental models can be utilized in the model output to improve optimum proportional solutions in any decision support system (DSS) for future sustainable agricultural land use planning.