Dynamic model to evaluate the water supply problems of green space in Shiraz

Due to rapid growth of urbanization and limited water resources, the need for effective urban water management is now more crucial than ever. In this paper, by using system dynamics approach, a supply and demand model has been developed. For this purpose, all factors affecting Shiraz city green areas has been modeled and by using that model the future water supply and demand is predicted. Then the current and future effective factors that will influence the system, such as the construction of second pipeline water transfer from the Doroudzan dam have been applied in modeling. Three management scenarios are studied: increasing efficiency of irrigation, completion of Shiraz city wastewater treatment plant and the construction of the Tange Sorkh dam. The results of this research show that the impact of Tange sorkh dam construction has a 5% decrease in shortages but using the treated wastewater has 3, 5, 7 and 9 percent decreases for using 30, 50, 75 and 100 percent of treated water for urban landscape, respectively. Simulation also showed that increasing the irrigation efficiency by 10 and 20 percent has 16 and 41 percent decrease on shortages, respectively. At the end, in order to navigate towards sustainable system, combination of scenarios are considered. These scenarios are: reducing the rate of population growth, decreasing domestic and green space water consumption per capita, increasing irrigation efficiency and using treated wastewater for green space. And finally we propose suggestions for system sustainability.