ИСТИНА

The long-term inland aquatic monitoring data of EANET were used for two areas of different geography and climate in Eastern Siberia (Baikal Lake basin) and Russian Far East: watersheds of Pereemnaya river (PR) and Komarovka river (KR), correspondently. The concentrations of major ions were compared in line with their temporal variations and acidifying-neutralizing capacities (including buffering potential). We could conclude the low buffering capacity of PR waters demonstrated by ratio of sulfate and nitrate sum to calcium as 1:1 under the relatively higher growth of SO4 concentrations. The concentrations of Ca are still more than SO4+NO3 in KR water throughout of growth all of them for last decades. We calculated the trends for these major ions in waters of both areas for 2007-2021 and evaluated their significance. With help of data on river water level and runoff we estimated the seasonal and annual discharge of major ions and total sulfur and nitrogen. The two approaches for approximation of intra-annual variations of ion concentrations were compared and used for estimation of their total discharge. Using the geospatial characteristics of watersheds and evaluated wet deposition of considered substances we quantify a specific surface runoff from both watersheds and potential inputs of atmospheric depositions on discharges with surface water.