Runoff sensitivity of Indian sub-continental river basins

Area of Science:

• Hydrology
• Climate Science
• Environmental Modeling

Background:

• Water availability is crucial for food and water security in the Indian subcontinent.
• Understanding climate change impacts on water resources is vital for sustainable management.

Purpose of the Study:

• To estimate water budget and runoff sensitivity to precipitation and potential evapotranspiration (PET) in Indian river basins.
• To compare the performance of the Variable Infiltration Capacity (VIC) model and Budyko's framework.

Main Methods:

• Utilized the Variable Infiltration Capacity (VIC) model and Budyko's framework.
• Employed two observational datasets for analysis across 18 major and 222 sub-basins.
• Assessed mean annual runoff sensitivity to precipitation and PET.

Main Results:

• Northern basins saw decreased precipitation; southern basins saw increased precipitation.
• Runoff decreased in Brahmaputra, Ganga, and Indus basins due to declined precipitation and increased PET.
• Runoff increased in several southern and eastern basins; VIC model showed better agreement with observations than Budyko's framework.

Conclusions:

• Runoff sensitivity to precipitation is higher than to PET in most Indian river basins.
• Significant uncertainties exist in water budget and runoff sensitivity estimations, necessitating multi-model approaches.
• The VIC model provides more reliable estimates compared to Budyko's framework for this region.