Temporal Dynamics of Sediment Characteristics in the Proglacial River of Gangotri Glacier: Impacts of Ablation and Climate Variability

Surface debris exerts profound influence on glacial dynamics as it changes the surface ablation and spatial distribution rates. This paper addresses the temporal variation in particle size distribution, sediment load (SSL), suspended sediment concentration (SSC) in the heading stream that flows out of the Glacier for the period (2017, 2018, 2019, 2022, 2023). Analysis of the data shows an increasing trend of SSC in relation to discharge since June and highest sediment load occurring in July and August. Silt particles (31–80%) followed by sand (18–45%) and clay (1–4%) dominated the suspended sediments. The proportions of sand particles were found to be less variable, whereas the proportion of the clay particles varied greatly when historical data of two distinct melt seasons (2004–2006 & 2017–2019) were compared. The poorly sorted sediments delivered are indicative of intense glacial erosion and kurtosis values during the melt seasoning suggest the climatic variations influence the area.