The effectiveness of management strategies to preserve the groundwater resources of Marvdasht-Kharameh plain using system dynamics

Recently, the increase in water demand and the pollution of water resources have threatened groundwater resources. The purpose of this research is to investigate the impact of the conservative scenarios of groundwater resources and its effect on the restriction of the aquifer volume reduction process using the system dynamics approach in Marvdasht-Kharameh plain.The current conditions of the aquifer during the statistical period of 2005-2018 were simulated and recalibrated according to the observed values of the aquifer volume. The scenarios have been applied in three ways to investigate the effect of climate change, changing the amount of water allocated to farmers from Doroudzan dam and changing the cultivation pattern under the scenarios SSP1-2.6 and SSP5-8.5 on the volume of the aquifer. In order to investigate the effect of climate change on Marvdasht-Kharameh aquifer in the period from 2021 to 2046, the rainfall data of GFDL-ESM4 model under two scenarios SSP1-2.6 and SSP5-8.5 were considered. The study of the impact of climate change and the release of the Darudzen dam showed that the volume and recharge of groundwater will decrease in the scenario SSP1-2.6 (50 and 49 million cubic meters respectively), and in the scenario SSP5-8.5 (54 and 67 million cubic meters respectively),. Also, by removing the rice crop from the cultivation pattern of Marvdasht-Kharameh plain in the future climate conditions under two scenarios SSP1-2.6 and SSP5-8.5, which will add 495 and 207 million cubic meters to the aquifer volume respectively, the greatest effect on increasing the aquifer volume will be achieved. It will have 30 and 50 percent reduction in the area under rice cultivation. Therefore, in order to manage and preserve groundwater resources, it is necessary to change the cultivation pattern and replace high consumption crops with low consumption crops.