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

A CMIP6 multi-model based analysis of potential climate change effects on watershed runoff using SWAT model: A case study of kunhar river basin, Pakistan

“…Baseline flow (26 m 3 /s) predicted to increase by 44.12 %, 69.11 %, and 110.9 % in the near, middle, and far futures for the RCP 8.5 scenario by Babar et al (2016) [ 12 ], whereas Mahmod et al (2016) [ 13 ] reported a 2 %, 11 %, and 2 % change in baseline flow (25 m 3 /s) in the near, middle, and far futures, respectively. Table 6 shows that projections for future flows indicate a rise of 112 % in the short-term, 151.2 % in the intermediate-term, and 193.8 % in the long-term according to research by Ghulam Nabi et al (2022) [ 67 ], while according to research by Mehmood et all.2016 shows decrease in most of the future projections under both scenarios. Hydrological model projections depend heavily on the details of the climatic data and calibration parameters with which they are made.…”

“…However, Mahmod et al (2016) [ 13 ] observed an inverse trend in their study of annual mean flow during different seasons. Ghulam Nabi et al (2022) [ 64 ] predict annual average flow at Ghari Habibullah will increase between 2021 and 2040, decrease between 2041 and 2070, and then increase again between 2071 and 2099. Our results are more in line with those of Ghulam Nabi et al (2022) [ 64 ] but we utilized CMIP6 models boasting improved physical, chemical, and biological process representation and higher spatial resolution compared to CMIP5 models (Stouffer et al, 2017; Zhu & Yang 2020) [ 66 ].…”

“…Ghulam Nabi et al (2022) [ 64 ] predict annual average flow at Ghari Habibullah will increase between 2021 and 2040, decrease between 2041 and 2070, and then increase again between 2071 and 2099. Our results are more in line with those of Ghulam Nabi et al (2022) [ 64 ] but we utilized CMIP6 models boasting improved physical, chemical, and biological process representation and higher spatial resolution compared to CMIP5 models (Stouffer et al, 2017; Zhu & Yang 2020) [ 66 ]. The predicted and baseline flow regimes are compared in Table 6 , which displays yearly and seasonal differences.…”

“…The downscaling, emission scenarios, climate model, and hydrological model used to estimate runoff all have their own set of unknowns. Runoff generation and water supplies are also significantly impacted by human activities such the growth of urban impermeable surfaces, reservoir operations, and other changes in land use need further research [ 64 , 65 ].…”