Several studies have noted that the annual runoff in glacierized watersheds could increase to reach a certain maximum level and then decline with glacier retreat ( Sunde et al., 2017 Laurent et al., 2020). The effects of climate change on runoff variation are complex, especially in glacierized watersheds ( Shrestha et al., 2020). On the one hand, climate change may result in increased annual precipitation and surface runoff on the other hand, as a result of increasing global temperatures, glaciers are experiencing accelerated retreat ( Guido et al., 2016). In general, rivers that receive substantial amounts of glacier melt are less vulnerable to droughts and floods than rivers that receive smaller amounts of glacier melt this is due to the regulating influence of glaciers on runoff ( Rai et al., 2019 Kneib et al., 2020 Wang et al., 2021). Runoff records in glacierized basins can be used to determine how climatic and glacial factors interact with one another ( Li et al., 2010). According to climate projections, future increasing temperatures and variations in precipitation may impact the majority of glaciated regions and, eventually, the world’s rivers and streams ( Didovets et al., 2021 Mengistu et al., 2021). The pace at which glaciers respond to climate change is dependent on their size the smaller a glacier is, the faster its response speed to climate change is ( Huss and Fischer, 2016). In mountainous regions, glaciers are not only essential contributors to streamflow and water budgets but are also important from the perspective of the natural ecological environment ( Brun et al., 2017 Gentili et al., 2020 Pelto et al., 2020). Glaciers are magnificent natural landscape features that take decades to hundreds of years to form. Moreover, the GDM was more responsive to changes in air temperature than to changes in glacier extent.
It was revealed that a 2☌ increase in the monthly average temperature could result in a 37.7% increase in the total discharge of the basin. Under all SSP scenarios, the projected runoff decline indicated that the peak runoff time had passed. During the calibration and validation periods, snow and ice melt contributed 25.14 and 25.62%, respectively, to the total runoff. It was determined that rainfall constituted the predominant source of runoff, followed by baseflow and ice melt. Four runoff components were simulated with the GDM: base flow, rainfall, ice melt, and snow melt. The GDM was driven with an ensemble of five downscaled CMIP6 datasets to examine the potential impacts of climate change on hydrologic processes in the basin. The resulting Nash–Sutcliffe efficiency (NSE) values were 0.82 and 0.81, respectively. The GDM was calibrated and validated against in situ observed discharge data for the 2007–20–2018 periods. In this study, a glacier dynamics model (the Open Global Glacier Model was coupled with a glacio-hydrological model to predict possible hydrological changes in the head watershed of the Urumqi River under three shared socioeconomic pathways SSP2-4.5, SSP3-7.0, and SSP5-8.5. In these regions, streamflow and glacier melt remain subject to significant uncertainties due to the lack of confidence in climate change projections and modeling methods. 4Himalayan Cryosphere, Climate and Disaster Research Center (HiCCDRC) Department of Environmental Science and Engineering, School of Science, Kathmandu University, Dhulikhel, NepalĪnalyzing climate change impacts on hydrology and future water supply projections is essential for effective water resource management and planning in the large river basins of Asia.3Faculty of Agricultural Engineering and Technology, PMAS-Arid Agriculture University, Rawalpindi, Pakistan.2University of Chinese Academy of Sciences, Beijing, China.1State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, China.Min Yang 1,2*, Zhongqin Li 1*, Muhammad Naveed Anjum 3, Rakesh Kayastha 4, Rijan Bhakta Kayastha 4, Mukesh Rai 1,2, Xin Zhang 1,2 and Chunhai Xu 1,2
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