Simulation of snowmelt-runoff under climate change scenarios in a data-scarce mountain environment

Pakistan is an agriculture-based economy and major proportion of irrigation water for its cultivated lands is abstracted from the Upper Indus Basin (UIB). UIB water supplies are mostly contributed from the high-altitude snow and glacier fields situated in the Hindukush-Karakoram-Himalayan ranges. Any change in the flows of these river catchments due to climate variability may result in the form of catastrophic events like floods and droughts and hence will adversely affect the economy of Pakistan. This study aims to simulate snowmelt runoff in a mountainous sub-catchment (Shyok River basin) of the UIB under climate change scenarios. Snowmelt Runoff Model (SRM) coupled with remotely sensed snow cover product (MOD10A2) is used to simulate the snowmelt runoff under current and future climate scenarios in the study area. The results indicate that (a) SRM has efficiently simulated the flow in Shyok River with average Nash-Sutcliff coefficient value (R-2) of 0.8 (0.63-0.93) for all six years (2000-2006) of basin-wide and zone-wise simulations, (b) an increase of 10% (by 2050) and 20% (by 2075) in SCA will result in a flow rise of similar to 11% and similar to 20%, respectively, and (c) an increase of 1 degrees C (by 2025), 2 degrees C (by 2050), 3 degrees C (by 2075) and 4 degrees C (by 2100) in mean temperature will result in a flow rise of similar to 26%, similar to 54%, similar to 81% and similar to 118%, respectively. This study suggests that SRM equipped with remotely sensed snow cover data is an effective tool to estimate snowmelt runoff in high mountain data-scarce environments.