Water Transfer and Watershed Development: A System Dynamics Approach

Zayandeh-Rud River Basin, in the central-Iran, is one of Iran's most strategic and important water basins with a semi-arid climate and large agricultural, industrial and domestic water uses. With continued growth in water use, the water resources management in Zayandeh-Rud Watershed is confronted with the challenge of providing sufficient and sustainable water resources for the various user groups. Although water resources development projects have doubled the available water mostly from transbasin water diversions, water shortages occur fairly soon after completion of each new water source. However, transbasin water diversion is still the major policy of water planners to address ongoing and upcoming water shortages. A system dynamics approach provides a framework for integrating the disparate physical and social systems important to Zayandeh-Rud River Basin's water resource management. This approach is used here to comprehend the interaction of different drivers of the problem and to see if transbasin diversion is the best solution. A simulation model is built based on Causal Loop Diagrams of the problem to find, for different scenarios, how various options of demand management and population control can be more effective when combined with transbasin water diversions, increasing water storage capacity and controlling of groundwater withdrawal.