Management of Groundwater Exploitation Applying Multi-Objective Programming: A Case Study of Firoozabad Plain

Overexploitation of groundwater resource may result in lowering groundwater table at a faster rate due to an imbalance in the total recharge and total withdrawal. In order to make a balance between groundwater exploitation and recharge, the major remedial measures suggested are to strengthen groundwater management, adopt water demand policies, raise water use efficiency, and to increase water supply. Because there is a trade off between farmers’ income and sustainability of groundwater based farming, it is essential that a mathematical model be used to study the effects of withdrawal on farmer's income and sustainability of farm. Such a model can determine optimal crop pattern, suitable irrigation strategies and irrigation methods at different levels of available irrigation water. The relationship between farmers’ income and the withdrawal was then examined using multi-objective programming. The data were obtained from a systematic random sampling method through which 112 farmers were chosen. The percentage decrease in the profit was less than that of the withdrawal for all representative farmers, based on the results obtained from multi-objective method. For example, 8% reduction of groundwater pumping could be imposed without a serious impact on the farmer's income (farmer's income falls about 4%). Finally, the results of this study can help farmers to choose crop patterns, irrigation strategies and irrigation methods in such a way that both farmers’ income and withdrawal are simultaneously optimized and lead to a decrease in extracting groundwater compared to the current status.