How does the suspended sediment yield change in the North Caucasus during the Anthropocene?

Processes linked to climate change and intensified anthropogenic pressure influence the environment, the hydrology and by extent the denudation processes in the Caucasus mountain belt. Quantitative assessments of sediment fluxes and their temporal evolution in this mountain region required for various environmental and engineering purposes, including the planning and maintenance of water reservoirs and other structures. This paper presents an analysis of the suspended sediment load data from almost 40 gauging stations located in the mountain part of the Terek river basin (North Caucasus, Russia). The collected dataset include river basins with various glacier cover (0%-20%) and human impact. All river basins show consistent decreases in mean annual suspended sediment load (SSL, kg/s) up to 1–2% per year during 1925–2018 (according to Mann-Kendall test). The cumulative deviation curve of the mean annual SSL for the last 60 years indicates that SSL has increased significantly from ca. 1970-1980 to 1990-2000 for the most North Caucasus rivers. However, after the 2000s mean annual values of the SSL show a stable decrease in all observed rivers. Possible mechanisms of observed changes are discussed. This study provides the data on climate-related changes in the sediment yield for a previously not investigated region.