State-of-the-art potential of the GRACE satellite mission for solving modern hydrological problems

The paper presents main results of GRACE mission using in such fields of study as estimations of components of basins water storage and water balance, hydrological modeling. It is shown that error of GRACE data is of the order 11 mm for watersheds with area about 100 000 km2 and decreasing with increasing of basin area. This accuracy made it possible to identify long-term and seasonal water storage. It is shown, that decreasing of total water storage in the Don basin for 2002–2019 is approximately equally caused by both soil moisture and groundwater changes. At the same time, minimum of groundwater was already reached in 2010, and soil moisture in 2015. Since 2016, Don basin groundwater changes a little during the winter period that is due, probably, with increase number of thaws and thinning of the freezing layer during this period. By the data of meteorological stations for the precipitation of cold period for the European Russia the value of their systematic error was estimated, it is about 20-25%. The comparison of the values of total water storage for the river basins of the north part of European part of Russia, according GRACE data and ECOMAG runoff modeling results has shown their good coincidence (NSE =0.78 0.89). In comparison with GRACE, ECOMAG shows a smaller increase in water storage during the winter and a faster decline during spring flood period. Currently, progress in the use of GRACE in hydrology is limited by low spatial-temporal resolution of data, which, within the framework of the GRACE mission itself, will not be improved in the coming years. At the same time, the principle of GRACE operation can be applied in future to various satellite constellations.