Water Security in Kowsar Dam Basin under Climate Variability: Application of System Dynamics Approach

Abstract In this study, we used a systemic approach to study the behavior of the water resources system in the Kowsar Dam basin. Generally, due to the complexity of the water system, one of the best tools for understanding the relationship between all components within a complex system is the system dynamic. System Dynamic is one of the methods that used to facilitate the relationships between separate systems but in connection with each other along with dynamic behavior. After modeling and calibrating the model, the behavior of the water system investigated over time. The results showed that during the simulation period, the water availability would be declining. While water demand, which is directly impacted by population growth, is rising. Under optimistic weather ions (first scenario), the surface water inflow is improving, yet increasing evaporation and outflow of water causes the water supply system to be vulnerable. As the water security index is in a better situation in the early years, it is expected to reach even lower than one at the end of simulation period. The results also indicated that the lowest water security index is related to pessimistic climatic conditions (second scenario). Therefore, demand management policies can play a significant role in the sustainable management of water resources by reducing water use per capita or increasing irrigation efficiency and reducing water consumption per hectare of agricultural production.