Investigating the effect of agricultural product price forecasting on groundwater level using systems dynamics, in order to simultaneously maintain the welfare of farmers and groundwater resources

Taleghan Dam is the main suplier of water required by the agricultural sector of Qazvin plain. Reducing the amount of water allocated to the Qazvin plain irrigation network and uncertainty about the welfare provided by farmers due to the interruption of the time between the production of the crop and its supply to the market, have caused farmers to seek welfare by reducing fallow and draining groundwater resources. In this study, with the aim of preserving groundwater resources and providing livelihood to farmers, the groundwater level in the irrigation network of Qazvin plain is simulated under six scenarios: 1) Continuation of current harvest without increasing cultivated area 2) Increasing cultivated area by reducing fallow 3) Simultaneous optimization of Cultivation pattern and distribution water with price forecasting 4) Simultaneous optimization of water Cultivation pattern and distribution water with price forecasting and reduction of functional vacuum 5) Simultaneous optimization of Cultivation pattern and distribution water with price forecasting and increasing efficiency Irrigation 6) Simultaneous optimization of Cultivation pattern and distribution water with price forecasting, increasing irrigation efficiency and reducing the yield gap using the system dynamics during the years 2002-2037 in Qazvin plain irrigation network. The results showed that the drop in groundwater level under scenario one and two will be on average 1.2 and 2.4 meters per year. Simultaneous optimization of the cultivation pattern and water distribution with price forecasting in scenario three, four and five droped groundwater level to 1.6, 1.4, 1.3 and 1.2 meters annually, while the welfare of farmers is compensated, too.