optimal cropping pattern for water resources management in sistan region of iran using goal programming method

the optimal cropping pattern for sistan water resources management was determined through a goal programming technique within the gams programming environment. results showed that the optimum cultivation area and net profit of the agricultural sector in the sistan region could increase up to 18.1 and 39.8%, respectively, compared to the current status. an increase in the farm irrigation efficiency from the current 35 to 55% would increase the net profit of the agricultural sector by 49.7% despite 6.4% reduction in water consumption. at the same time, 20% increase in the efficiency of water delivery system to farmlands would lead to 8.2 and 17.2% increases in the cultivation area and net profit, respectively. the results of combining these two management scenarios indicated that farming net profit would increase by 64.3%, while total water consumption in agricultural sector would decrease by 2.3%. under wet condition, cultivated area and net profit would respectively increase about 32 and 44%. however, upon drought years, the cultivated area and net profit would experience 86.9 and 87.3% loss, respectively.