Investigation of Water Supply and Cropping Pattern on Water Level Rising in Abbas Plain of Ilam Province using System Dynamics Approach

In irrigation management, the amount and quality of irrigation water is very important. Inappropriate water and soil quality will cause the plant to grow, destroy the soil structure and eventually reduce crop yield. In this study, according to the field measurement, the boundaries of the system were investigated, a conceptual model was developed to determine causal relationships, structural test, and the extent test used for the system dynamics method. Scenarios including water supply from Karkheh Dam and wells of the region as well as crop pattern were evaluated and selected. The conceptual model was based on five sub-models: water demand, water supply, environmental stresses, water economy and environment. The results showed that the use of Karkheh Dam water of 160 million cubic meters and the extraction of 90 million cubic meters of the plain aquifer will keep the groundwater level at a distance of 10 meters from the soil surface and will supress the problem of rising groundwater level. In crop pattern scenarios, the model results were the use of crop pattern with emphasis on increasing forage and beet levels to prevent drainage.