Quantifying present and future glacier melt-water contribution to runoff in a Central Himalayan river basin

Abstract

Water supply of most lowland cultures heavily depends on rain and melt-water from the upstream mountains. Especially melt-water release of alpine mountain ranges is usually attributed a pivotal role for the water supply of large downstream regions. Water scarcity is assumed as consequence of glacier shrinkage and possible disappearance due to Global Climate Change, particular for large parts of Central and South East Asia. In this paper, the application and validation of a coupled modeling approach with Regional Climate Model outputs and a process-oriented glacier and hydrological model is presented for a Central Himalayan river basin despite scarce data availability. Current and possible future contributions of ice-melt to runoff along the river network are spatially explicitly shown. Its role among the other water balance components is presented. Although glaciers have retreated and will continue to retreat according to the chosen climate scenarios, water availability is and will be primarily determined by monsoon precipitation and snow-melt. Ice-melt from glaciers is and will be a minor runoff component in summer monsoon-dominated Himalayan river basins

Evaluation of an ice ablation model to estimate the contribution of melting glacier ice to annual discharge in the Nepal Himalaya

“…Our calculation of a contribution of 58.3% glacial meltwater to annual discharge for the Langtang Khola is larger than the 45% calculated for the same basin by Immerzeel et al [2012], but within the boundaries of our sensitivity analysis (Tables 7 and 8) and provides an independent check that our ice ablation approach appears to work reasonably well. Prasch et al [2012] also found an ice-melt contribution of 50% to total runoff in a central Himalaya basin, based on a regional climate model and process-oriented and hydrologic modeling.…”

Evaluating the impacts of climate change and crop land use change on streamflow, nitrates and phosphorus: A modeling study in Bavaria

“…SCALMET preserves energy and mass at the scale of the RCM grid and has been used to overcome the scale gap between the atmospheric models and hydrological models for investigating climate change impacts (e.g. Prasch et al, 2013;Zabel and Mauser, 2013). More detailed explanations of the climate change simulations and their post-processing is provided in Muerth et al (2013).…”

Reconstruction of the annual mass balance of Chhota Shigri glacier, Western Himalaya, India, since 1969

“…Therefore, understanding the evolution of Himalayan glaciers is of great interest in diagnosing future water availability in these highly populated watersheds (e.g. Kaser and others, 2010; Thayyen and Gergan, 2010; Prasch and others, 2013). A reliable prediction of glacier behaviour in the future demands an assessment of their response to climate in the past.…”