Predicting of the Climate-induced Depletion in Groundwater Level and Storage: A case in Akarçay Basin

Abstract

In this study, we examined the potential impact of climate change on the depletion of groundwater levels and storage. To achieve so, we simulated the groundwater flow using the HİDROTÜRK hydrogeological model under the climate change projections considering the RCP4.5 and RCP8.5 scenarios. To estimate the model forcing input (recharge and evapotranspiration) for the hydrogeological model, we used precipitation and temperature outputs from two Global Circulation Models, namely HadGEM2-ES and MPI-ESM-MR. To assess the changes in groundwater level and storage, we applied our experimental design in the Şuhut alluvial aquifer in Akarçay Basin (Turkey). The study revealed that there is not necessarily a substantial difference tracked over the estimated groundwater levels between the RCP4.5 and RCP8.5 scenarios until the end of 2050s. Yet, a significant reduction in the hydraulic head (approximately 114 m) and storage change (-17.25 %) – particularly in the western part of the aquifer – is expected in 2100, according to RCP8.5. This study confirmed that the selected climate model not only leads to the different predictions in the groundwater depletion, yet also results in a different degree of confidence in the model simulations.