Changes in the hydro-climatic regime of the Hunza Basin in the Upper Indus under CMIP6 climate change projections

Abstract

The Upper Indus Basin (UIB) heavily depends on its frozen water resources, and an accelerated melt due to the projected climate change may significantly alter future water availability. The future hydro-climatic regime and water availability of the Hunza basin (a sub-basin of UIB) were analysed using the newly released Coupled Model Intercomparison Project Phase 6 (CMIP6) climate projections. A data and parameter parsimonious precipitation-runoff model, the Distance Distribution Dynamics (DDD) model, was used with energy balance-based subroutines for snowmelt, glacier melt and evapotranspiration. The DDD model was set up for baseline (1991–2010), mid-century (2041–2060) and end-century (2081–2100) climates projections from two global circulation models (GCM), namely EC-Earth3 and MPI-ESM. The projections indicate a substantial increase in temperature (1.1–8.6 °C) and precipitation (12–32%) throughout the twenty-first century. The simulations show the future flow increase between 23–126% and the future glacier melt increase between 30–265%, depending on the scenarios and GCMs used. Moreover, the simulations suggest an increasing glacier melt contribution from all elevations with a significant increase from the higher elevations. The findings provide a basis for planning and modifying reservoir operation strategies with respect to hydropower generation, irrigation withdrawals, flood control, and drought management.

Matrilineal phylogeny and habitat suitability of the endangered spotted pond turtle (Geoclemys hamiltonii; Testudines: Geoemydidae): a two-dimensional approach to forecasting future conservation consequences

“…These Himalayan glaciers are receding faster as a result of rising temperatures induced by greenhouse gas emissions, considerable unpredictability in precipitation trends, and an increase in glacier melt, which will have catastrophic societal and geomorphic impacts on IGB river basins ( Xu et al, 2009 ; Kääb et al, 2012 ; Nepal & Shrestha, 2015 ; Azam et al, 2021 ). Such amplified climate changes and spatio-temporal variations have greatly affected the snow cover and surface water areas of the IGB river basins ( Siderius et al, 2013 ; Kiani et al, 2021 ; Mondal et al, 2021 ; Nazeer et al, 2022 ; Uereyen et al, 2022 ). In consequence, hydrological extremes, such as floods and droughts, may endanger both human and wildlife habitats in the IGB river basins throughout the 21st century ( Wijngaard et al, 2017 ; Veh, Korup & Walz, 2020 ; Dahri et al, 2021 ).…”