Impact of spatial and temporal changes in climate on the Kunhar River Watershed, Pakistan

The present study explores the spatio-temporal variation in the projected runoff due to the Kunhar River basin climate changes. To project the future climate, two global circulation models (CGMs), Meteorological Research Institute Coupled Ocean-Atmosphere General Circulation Model 3 (MRI-CGCM3) and Hadley Centre Global Environmental Model version 2 (HadGEM AO2), were used under the Representative Concentration Pathway (RCP) 4.5, 8.5 scenarios. The Soil and Water Assessment Tool (SWAT) was used as a hydrological model. By combining the results of both GCM, it was found that the average annual precipitation, minimum, and maximum temperature may increase by 336 (238–434) mm, 4.2 (2.78–5.6) °C, and 4.2 (2.9–5.4) °C, respectively, in comparison to baseline values, until the end of this century. The annual streamflow may increase by 14% (14 m 3 /s) and 20% (20 m 3 /s) under RCP 4.5 and RCP 8.5, respectively, in the far future. However, the changes in seasonal flow are more likely to be dominated by the annual. Peak flow may shift slightly backward compared to the baseline. The seasonal changes in runoff due to climate change may lead to different issues, viz., drought, water scarcity, and floods.