ESTIMATION OF AUFEIS RESOURCES IN THE INDIGIRKA RIVER BASIN

On the basis of corrected Landsat data for 2013-2017, a modern assessment of aufeis in the Indigirka River basin and its partial catchments with an area of 1830 to 305 000 km2 was conducted. The potential contribution of the aufeis flow to the formation of the water balance of rivers during various phases of hydrological regime was calculated. During the phase of the maximum development, the aufeis area of partial catchments ranges from 0.30 to 1.49%, reaching 0.54% of the total area of the Indigirka River basin. The aufeis resources (water content in aufeis) of the Indigirka River basin are 10.0 mm of the runoff level or in total 3.5 km3 . For individual rivers, the aufeis flow can reach 5-28 mm per year, which makes up 2.6 to 20.8% (an average is 8.1%) of river runoff. On average, water resources stored in aufeis make up 235% of the winter river flow (135% for the Indigirka River basin). The contribution of the aufeis flow during the spring flood can reach 39% and is 13.7% in the outlet of the Indigirka River basin. The ambiguous impact of climate change on aufeis (reducing their area and increasing their number) requires further detailed studies.