THE INFLUENCE OF BASIN LANDSCAPE PATTERN ON SPECIFIC LOW-WATER FLOW OF SMALL RIVERS IN THE NORTH AND SOUTH OF CHUKOTKA

Abstract

The article analyses landscape factors that determine the runoff of small Arctic and Subarctic rivers in the far northeast of Asia. The paper considers hydrography, structure of permafrost landscapes and their hydro-chemical characteristics, and the spatial dynamics of low-water runoff in the basins of the Ugolnaya-Dionisiya and Yanranayvaam rivers. It has been established that sustainable water intake depends on the ratio of land-scapes generating and depositing the permafrost runoff, namely Arctic char gravelly shrub tundra, lowland tussock tundra and hummock swamps. The low-water runoff of 20-50 l/km2·sec is typical for the sources of rivers, where seasonal char ice melts in the slope deposits and condensation waters are formed. Melt water of sea-sonal intra-surface soil ice on the gentle slopes of tundra hummocks provides specific runoff of 10-20 l/km2·sec. Upland and lowland marshes deposit above-frozen waters, and their runoff is less than 10 l/km2ˑsec. Using the example of two catchment basins, it is shown that the decrease in precipitation in the north of Chukotka is almost completely compensated by the formation of condensation waters. At the same time, inground seasonal infiltration soil ice is replaced in Arctic landscapes by infiltration-condensation char ice, and its melt water makes up for the loss of surface runoff.