Changes in river runoff resources, volumes of water intake from surface water sources, and discharge of wastewater into them under contemporary global warming in the basins of the Volga–Kama and Angara–Yenisei reservoirs were analyzed by comparison with the base period, characterized by colder climatic conditions and the largest volumes of water intake and wastewater discharge. The water stress index (WSI) and the index of reciprocal dilution of polluted wastewater (RDI) were examined to reveal features of the change in the water-industry load on river runoff resources in reservoir basins during the period of contemporary global warming (compared to the previous base period) as a result of climate change combined with changes in the volumes of water intake and discharge of polluted wastewater. Both indices were calculated relative to the annual free flow for years of average river flow and the flow of low-water years. The dilution factor was estimated relative to the annual total flow. 1. The basins of the Volga–Kama reservoirs are characterized by a higher level of water-industry load, which is especially noticeable in the significantly lower RDI. 2. When calculating the dilution factor relative to the annual total flow, the level of water-industry load turns out to be much lower both in the base period and in the period of contemporary global warming. 3. At the same time, under global warming conditions, the dilution level of polluted wastewater in the basins of all reservoirs exceeds the minimum required level.
Георгиади et al. (Thu,) studied this question.