System Dynamics Modeling of Dam and Groundwater for Optimal Water Management (Case study: Golak Dam)

Nowadays, beside water shortage, we face with mismanagement in water resources. In this situation, optimal water management especially in arid and semi-arid areas is very important. The increase of water demands due to population growth, industrial and agricultural developments was inevitable. On the other hand, due to water resources limitations and principal of sustainability in water management, water allocation, is a very challenging work. Hence, for answering to agricultural, municipal, industrial and ecological demands with high reliability, we need very rigorous programs. The purpose of this paper is to investigate the effect of storage dam on Hesaroo river in Golak area for floodwater collection at raining times and also providing so called demands to recharge the alluvial aquifer, downstream plain and also rich the groundwater. System Dynamic Modelling (SDM) System Dynamic Modelling is a methodology for studying feedback systems. Forrester introduced SDM as a methodology for decision-making in industrial management problems [1]. SDM is extensively used for water resources modelling due to its flexibility, effectiveness in assessing different management options, ease of operation and suitability for encouraging stakeholder involvement [2]. For simulation, first we made a basic demand and supply framework and our model in Vensim is originated from that framework. In this model, all demands, supplies and also groundwater has been considered.Developed model:We identified shortage in groundwater, agricultural and environmental demands as the most important elements in Golak area. For that reason, after making causal loop diagram (CLD), we developed a Stock and Flow Diagram (SFD) for Golak dam. This model includes Golak storage, evaporation from it, groundwater supply, municipal, agricultural, industrial and environmental demands. Because of groundwater crisis in that area, we added a new Stock to model for distribution of floods to enrich the groundwater supply. The proposed system dynamics model was validated by comparing estimated values to historical data. Validation proved the accuracy of our model.3.1. SFD model in VENSIM In order to investigate the effect of distribution of floods for enrichment of groundwater supply, we run the model (Fig.1) and analyze the effects of distribution while all demands are answered. The results show significant increasing in groundwater’s elevation. This study has showed that System Dynamics is a useful decision support tool for the simulation of sustainable water resource management. Results of this study showed the effect of Golak dam on groundwater storage by distribution of floods to enrich the groundwater. According to this paper, this model can use for the implementation of different managing and operational policies on the water resource allocations. Different Scenarios such as altering the river flow due to dry periods and changing in various demands because of growth in population and industry can be simulated and analyzed by this model.