Assessment of climate change impact on hydrology of isser river basin, algeria

This research assessed the impact of climate change on hydrology over Isser River basin in Algeria using the data of 4 hydrometric stations:  Sidi-Abdelli, Chouly, Maghnia, Sidi-Bel-Abbes (North-West Algeria). Using climate projection from the Global Circulation Model (GCM) CanESM2, the Statistical DownScaling Model (SDSM) was used to downscale the GCM data from RCP2.6, RCP4.5 and RCP8.5 emissions scenarios for future climate predictions. The outputs generated from the statistical downscaled model (precipitation and temperature) were used to derive a hydrological model GR2M. GR2M was calibrated and used to assess the hydrological response over the Isser River basin due to climate change. GR2M hydrological model simulation was run for the baseline and three future scenarios (2030s, 2060s, and 2090s) to understand climate change impacts on river runoff. The average water balance components of the RCP2.6, RCP4.5 and RCP8.5 scenarios for the three periods were compared with the baseline hydrological simulation. Results demonstrates that the hydrology of the basin is very sensitive to climate change. The projected minimum and maximum temperatures increase in three scenarios are within the range projected by IPCC which reported average temperature will increase in future for the North Africa. The increase in temperature will be accompanied with decrease in the total annual precipitation for the three scenarios RCP2.6, RCP4.5, RCP8.5 at the four stations indicating that the watershed will be hotter and drier in the future.