Future climate projections using the LARS-WG6 downscaling model over Upper Indus Basin, Pakistan

Area of Science:

• Climatology
• Environmental Science
• Hydrology

Background:

• The Upper Indus Basin (UIB) is a critical region for water resources.
• Understanding local-scale climate change impacts is essential for adaptation strategies.
• Previous studies often lack high-resolution projections for this specific basin.

Purpose of the Study:

• To investigate local-scale projections of precipitation and temperature in the UIB.
• To downscale climate data using Regional Climate Models (RCMs) and a weather generator.
• To assess future changes under Representative Concentration Pathways (RCPs) 4.5 and 8.5.

Main Methods:

• Utilized six CORDEX RCMs for downscaling.
• Employed the Long Ashton Research Station Weather Generator (LARS-WG6) for daily data.
• Analyzed projections for maximum temperature (Tmax), minimum temperature (Tmin), and precipitation (pr) for mid-century and end-century periods.
• Validated LARS-WG6 model performance for temperature and precipitation simulation in the UIB.

Main Results:

• All RCMs project a continuous increase in temperature across the UIB.
• Higher temperature increases are projected under RCP 8.5 compared to RCP 4.5.
• Precipitation projections show non-uniform trends, with varying RCM agreement on increase or decrease.
• An overall increase in precipitation is projected by the ensemble of RCMs.

Conclusions:

• The UIB is projected to experience significant warming, particularly under higher emission scenarios.
• Uncertainty exists in future precipitation patterns, necessitating robust water management planning.
• Downscaled RCM data using LARS-WG6 provides valuable insights for local climate change impact assessments in the UIB.