Capacity Design of Inter-Basin Water Transfer Systems Considering Decision Making Criteria in the Source and the Target Basins

Increase of need to water resources in order to supply various demands has caused complicated limitations and problems in access to fresh water. In Iran this issue is serious due to unbalanced spatial distribution of limited water resources and high demand sites. Accordingly, for a long time the interbasin water transfer has been a proposed approach to solve the problem of water shortage. Due to various decision making criteria and factors, studies of the inter-basin water transfer projects have been known as complex and difficult problems in literatures. In this research, optimum design of capacities for Behesht-Abad inter-basin water transfer system, from up-stream Karoun basin to Gavkhooni basin, has been studied through 6 possible scenarios using the river basin simulation model MODSIM. By applying multi-criteria decision making and fuzzy sets theory, the more beneficial scenario and justifiable volume of water transfer are selected. The simulation results show that there is a recent period of 10 year drought in basin’s river flow time series. So, the results are also compared for the hydrological drought period in the basin. It is seen that when considering the normal long term time series for river discharges, volume of 190 MCM is a sustainable limit for studied inter-basin water transfer system. Considering the recent drought time series, this volume would be 147 MCM.