Mahdi Frotan, Majid Rezaei Banafsheh Daragh ,
Volume 0, Issue 0 (3-1921)
Abstract
Climate change is a significant threat to water resources, potentially altering precipitation patterns and increasing the likelihood of droughts in certain regions. This study aims to project future drought conditions in the Aras Downstream Watershed for the period 2025-2050, employing CMIP6 climate models (NorESM2-LM, CanESM5, and MPI-ESM1-2-HR) and the CMhyd software. Historical daily precipitation data from the selected models were compared with data from five stations (Parsabad, Aslan Duz, Jafarabad, Dasht, and Shorgol) within the study watershed. The comparison was conducted using statistical metrics (R2, MAE, MSE, and RMSE), and the results indicated the superior performance of the MPI-ESM1-2-HR model in precipitation estimation. This model was bias-corrected using the LS method in the CMhyd software, and future precipitation was projected based on the outputs of three scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5). The Standardized Precipitation Index (SPI) was employed on a three-month timescale to assess drought conditions. The findings revealed that the overall region will experience normal conditions based on SPI classifications. However, there will be a relatively higher potential for drought in the southern part of the watershed under the SSP2-4.5 and SSP5-8.5 scenarios compared to SSP1-2.6. The analysis of the network station averages indicated that the optimistic scenario suggests favorable conditions for the watershed, while the intermediate and pessimistic scenarios suggest a contrasting picture, with drought becoming prevalent across the entire region in the coming decades.
