SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Application of SWAT in hydrological simulation of complex mountainous river basin (Part II: Climate change impact assessment) 
Authors:Marahatta, S., D. Aryal, L.P. Devkota, U. Bhattarai and D. Shrestha 
Volume (Issue):13(11) 
Article ID:1548 
URL (non-DOI journals): 
Broad Application Category:hydrologic only 
Primary Application Category:climate change 
Secondary Application Category:hydrologic assessment 
Watershed Description:4,988 km^2 Budhigandaki River, a transboundary river which drains part of the Tibetan Plateau in China (about 25% of the basin) with the remaining portion in north-central Nepal. 
Calibration Summary: 
Validation Summary: 
General Comments: 
Abstract:This study aims at analysing the impact of climate change (CC) on the river hydrology of a complex mountainous river basin—the Budhigandaki River Basin (BRB)—using the Soil and Water Assessment Tool (SWAT) hydrological model that was calibrated and validated in Part I of this research. A relatively new approach of selecting global climate models (GCMs) for each of the two selected RCPs, 4.5 (stabilization scenario) and 8.5 (high emission scenario), representing four extreme cases (warm-wet, cold-wet, warm-dry, and cold-dry conditions), was applied. Future climate data was bias corrected using a quantile mapping method. The bias-corrected GCM data were forced into the SWAT model one at a time to simulate the future flows of BRB for three 30-year time windows: Immediate Future (2021–2050), Mid Future (2046–2075), and Far Future (2070–2099). The projected flows were compared with the corresponding monthly, seasonal, annual, and fractional differences of extreme flows of the simulated baseline period (1983–2012). The results showed that future long-term average annual flows are expected to increase in all climatic conditions for both RCPs compared to the baseline. The range of predicted changes in future monthly, seasonal, and annual flows shows high uncertainty. The comparative frequency analysis of the annual one-day maximum and -minimum flows shows increased high flows and decreased low flows in the future. These results imply the necessity for design modifications in hydraulic structures as well as the preference of storage over run-of-river water resources development projects in the study basin from the perspective of climate resilience. 
Keywords:climate change; fractional difference; SWAT; quantile mapping; extreme flow