Risk assessment of climate change impacts on groundwater level (Case study: Gotvand Aghili aquifer)

In the present study the impacts of climate change on groundwater levels in the Gotvand Aghili aquifer was investigated. For this purpose, groundwater was simulated using the MODFLOW model in the GMS framework for a period of 2002-2012. After calibration of model the values of RMSE for steady and unsteady conditions were 0.751 and 0.852m respectively, and average correlation coefficient of 0.82 was obtained for the verification of model. Then outputs of 10 AOGCM models under the RCP8.5 emission scenarios, the latest assessment report of IPCC, were used to simulate the climate parameters and study their impact of groundwater levels in future. For this purpose, the periods of 2000-1971 and 2024-2015 were selected as the base forecast periods respectively. The 5 climate scenarios (at the risk of 0.1, 0.25, 0.5, 0.75 and 0.9) were used for simulation of climate parameters for the future period. Then groundwater levels were predicted for the future period under these scenarios. Based on the results under the risk level of 0.1 the aquifer will experienced the biggest drop of 1.8m and under scenario with risk level of 0.9, the groundwater level will increased 0.48 meters during the future 10 years of 2024 to 2015.