Assessment of Influences of Anthropogenic and Climatic Changes in the Drainage Basin on Hydrological Processes in the Gulf of Ob

Changes in the runoff of rivers flowing into the Arctic Ocean caused by climate changes and increasing anthropogenic load lead to foreseeable transformations of hydrological processes in the mouth areas of the rivers. Climatic, water-balance, and hydrodynamic models were successively applied to evaluate the effect of climatic and anthropogenic changes in the drainage basin of the Ob river estuary on seasonal hydrological processes in the Gulf of Ob. Climate changes along with considerable seasonal redistribution of river runoff in the drainage basin of the Gulf of Ob, mostly due to its increase in winter, were found to cause no significant changes in the seasonal hydrological mouth processes in 1980–2018. Estimates for a period of up to 2050 showed that climate changes under various scenarios will cause an increase in streamflow from the basin, which will reduce the penetration of saltwater into the gulf.