Assessing climate sensitivity of the Upper Indus Basin using fully distributed, physically-based hydrologic modeling...

Area of Science:

• Hydrology and Climate Science
• Water Resource Management

Background:

• The Upper Indus Basin (UIB) faces potential water scarcity due to climate change impacting snow and glacier melt.
• The region's water resources are critical for Pakistan's downstream areas.

Purpose of the Study:

• To investigate hydrological changes and water resource variability in the UIB under future climate scenarios.
• To project streamflow changes up to the end of the 21st century.

Main Methods:

• Utilized a coupled hydrologic/hydraulic model (MIKE SHE/MIKE HYDRO RIVER) calibrated with streamflow data.
• Employed bias-corrected climate projections from the coordinated regional climate downscaling experiment (CORDEX) for RCP 4.5 and RCP 8.5 scenarios.

Main Results:

• Projected streamflow increases of 86% (RCP 4.5) and 97% (RCP 8.5) by the end of the century.
• Warming trends (2.3-4°C) are expected to significantly boost snowmelt, particularly increasing winter flows by 300% historically.
• Annual average water availability under RCP 8.5 is estimated at 4500 m³/s.

Conclusions:

• Increased water availability may alleviate water stress but poses significant flood risks.
• Enhanced flood defenses and storage are crucial for managing increased water resources and mitigating flood hazards in downstream areas.