Dynamics of suspended sediment sources in the Kuoqionggangri glacier Basin, Tibetan Plateau, under diverse hydrometeorological conditions

The dynamics of suspended sediment sources (SSS) in glacial basins are critical for understanding land surface processes in the context of global change, and present challenges in the fields of cryospheric hydrology and sediment transport research. This study employed SSS fingerprinting techniques to quantify and analyze variations in SSS influenced by glacier melt, snowmelt, and rainfall in the Kuoqionggangri Glacier Basin, located in the southern Tibetan Plateau. Furthermore, the study proposes a methodological strategy for validating SSS estimation results through hydrological modeling. The findings indicate substantial variation in sediment contributions from different sources, which correlate with the dynamics of runoff components. The glacier zone, which constitutes 14.8 % of the area, contributed 52.8 % of sediments, highlighting its high erosion intensity. The extremely high-altitude bare land (>5400 m), high-altitude bare land (4800 ∼ 5400 m), and meadow zones, comprising 51.7 %, 18.8 %, and 14.7 % of the area, respectively, contributed 19.7 %, 21.0 %, and 6.5 % of the sediments on average. During glacier melt events, the glacier serves as the predominant SSS (70.8 %) of the sediment, with glacier melt dominating the runoff at 85.8 %. During snowmelt events, the glacier and extremely high-altitude bare land zones were the main SSS areas, contributing 53.5 % and 22.5 % of the sediment, respectively. With snowmelt comprising the greatest proportion of runoff at 70.7 %, it is suggested that snowmelt-induced erosion predominantly occurs in bare land with altitudes above 5400 m. During rainfall events, the glacier, extremely high-altitude bare land and high-altitude bare land zones were the primary SSS areas, contributing 34.2 %, 23.8 %, and 36.4 % of the sediment, respectively. With rainfall accounting for the largest share of runoff at 64.9 %, it is indicated that rainfall-induced erosion mainly occurs in bare land with altitudes above 4800 m. This study provides initial insights into the dynamic characteristics of SSS in a glacier basin under different hydrometeorological conditions. The findings can assist management authorities in the effective implementation of soil and water conservation measures in alpine regions.