چكيده به لاتين
The study area of Isfahan - Borkhar is one of the study areas of Gavkhoni Watershed, Iran. This area is the highest population density in the Gavkhoni area. The hydrograph of Isfahan - Borkhar Aquifer shows the critical conditions of this aquifer and a 7 meters fall in groundwater level within 15 years, and the region is facing economic, social and environmental issues with the continuation of these conditions in future years. In this region, total water use was about 780 MCM in 1390; moreover, water use in agriculture is about 70 percent of total water use in this year, and groundwater extraction for agriculture is 86 percent of water use in agriculture. Thus, providing a solution for achieving groundwater sustainability in the area is one of the most important requirements for dealing with the crisis.
Achieving sustainable groundwater conditions can be a result of demand side management, such as reduction in groundwater usage for agriculture. A major question for much of the agricultural community in Isfahan - Borkhar is the effects of reduction in groundwater use on the hydrologic, economic, and environmental conditions of the area. This research uses hydrologic and economic models, and its purposes are to evaluate the hydrologic and economic effects of transitioning to sustainable groundwater management in the study area of Isfahan - Borkhar.
To achieve this goal, we need to model the complex hydro-economic dynamics of groundwater use in the study region. This modeling was accomplished by integrating groundwater and surface water simulation model and agricultural production model. The resulting hydro-economic model was used to simulate changes in groundwater volume and level, changes agricultural cropping patterns, and calculation of production costs and benefits of agricultural products during a 10-year simulation period and the prediction of groundwater level over the next 30 years.
The hydrologic modeling results show Isfahan – Borkhar aquifer is not presently on a path of sustainable groundwater management. A reduction in groundwater pumping for agriculture use in the range of 18-25% from current amounts is needed to stabilize average groundwater level in the study region. Economic model shows that the agricultural community in this region will lose about 3 and 9 billion by reducing this amount of groundwater extraction. Consequently, the groundwater level will rise to 8 and 13 meters until 1420 by introducing these two optimal cropping patterns in the prediction model.
Keywords: Groundwater sustainability, Demand side management, study area of Isfahan – Borkhar, Hydro-economic model, System dynamics
