Water resources planning in Karkheh basin according to the agricultural GDP, equality in the distribution of agricultural and the supplying of environmental requirement

In the study of water resources development projects, in addition to technical issues, economic, social and environmental aspects should also be considered. Therefore, the use of simulation model is the key to develop a reasonable strategy and to decide on the future of water resources in each region. To simulate Karkheh basin, MODSIM model is used as a decision support system. Two main types of policies are investigated, one related to the pattern of water consumption in terms of minimum, medium and maximum consumption, and the other related to how to develop basin dams and add them to the system. The indicators used to study each of the scenarios include the area under cultivation, the GDP from agricultural sector, the environmental flow to maintain the Hoor al-Azim wetland and, most importantly, the Williamson coefficient, which examines the issue of reducing economic inequality and equilibrium in the distribution of agricultural income among the provinces of the Karkheh basin. Finally, using the multi-criteria decision making methods (MCDM) called AHP and ANP and also the MCDM software Super Decision, the results are compared and the policies ranked. The results show that in both AHP and ANP methods, scenarios including the development of the under study dams and minimal water consumption (which is an ideal scenario) and then the scenario of development of under study and construction dams in medium water consumption, respectively, are the best policies for planning in the basin based on the considered criteria.