Assessing the effect of climate change on groundwater levels in the upcoming periods, case study: Chamchamal Plain

In this research, the effect of climate change on the groundwater level of Chamchamal Plain in the two 20-year periods was investigated. The GMS groundwater model was used to simulate the aquifer and was calibrated and verified for evaluation and validation of the model for two periods of 18 months, respectively. In order to investigate the effect of climate change on the fluctuations of groundwater level in the region, six AOGCM models were used under three emission scenarios A2, A1B, and B1 in the upcoming period. Then, two methods of weighting and extraction of probabilistic levels were used to consider the uncertainty prediction of climate change models for temperature and precipitation parameters. The predicted climatic variables for scenarios A2, A1B and B1, and two Probability levels 90% and 50%, respectively, show the average temperature changes of +0.57, +0.57, +0.57, -0.04 and +0.6 °C and average precipitation variation of +0.12, -1.8, +2.49, -31.78 and -2.33 during the period 2011-2030. Similarly, for the period 2046-2065, the average temperature changes were +1.92, +2.12, +1.46, +0.98 and +2.3°C, and the average precipitation variation was -20.59, -26.07, -19.55, -47.15 and -15.74 percent. Finally, the effect of climate change on the aquifer level was determined under scenarios. The results showed the groundwater level, under scenarios A2, A1B and B1 and two probabilistic levels of 90 and 50 percent for the periods 2011-2030 and 2046-2065 will drawdown between -9.6 to -17.92 meters, which is Compared to the period 1996-2015, it showed a change in level between -1.06 to -9.38 meters.