Integrated water resources management at basin scale (IWMsim) using a system dynamics approach

Assessment of the economic, social and environmental effects of water projects is required to achieve sustainable development. Therefore, the development of a model that can simulate the different dimensions of water resource development projects and interactions between different methods of operation, can be helpful to managers and decision makers in the water sector. The main objective of present study was development of water integrated model (IWMsim) to evaluate different management policies and contribute to improve decision-making in large scale systems, using system dynamics modeling approach. The developed model is capable of simulating the impact of various effective factors in the water utilization on economic and environmental sustainability. In this investigation, to study interactions between environmental and economic effects of water resources development projects, two macro indicators of national costs and national revenue were developed. The developed model was calibrated and validated using long-term climatological, hydrological, agricultural and environmental data of Varamin case study. The developed system dynamics model evaluation showed that the model was able to simulate key variables such as relative crop yield (RMSE=14.2%, ME=20% and R2=0.92), groundwater levels (RMSE=0.37m, R2=0.92 and ME=0.45m) and groundwater salinity (RMSE=57 μS/cm, R2=0.79 and ME=148μS/cm) with reasonable accuracy.