HETEROGENEITY OF RUNOFF OF SMALL MOUNTAIN STREAMS OF THE UPPER KOLYMA BASIN AT THE BEGINNING OF WINTER LOW WATER
V.E. Glotov
Shilo Northeastern Integrated Research Institute, Far Eastern Branch of the Russian Academy of Sciences, Magadan, Russia
Keywords: permafrost zone, Upper Kolyma, small mountain streams, terrains, runoff heterogeneity, zero curtain layer, winter low water period, water-absorbing taliks
Abstract
The article presents the results of a study of the patterns and causes of heterogeneity in the cessation of runoff in October and the first half of November in the upper reaches of the mountain rivers of the Upper Kolyma. Three levels of heterogeneity were identified. The first level is associated with the diversity of geological terranes in the study area. The highest runoff values (annual layer, runoff modules in September and in the first winter month of October) are found in the area of the Viliginsky terrane which lithodynamic complex is dominated by tuffaceous rocks. The lowest values are observed in the Inyali-Debinsky terrain, where clayey and siliceous shales prevail. The second level of heterogeneity is expressed in the duration of runoff after the onset of the winter low water period, which varies from several days to 45 days. This is determined by the recharge of groundwater due to the melting of ice at the base of the seasonally thawed layer (STL). Consequently, the heterogeneity of this level is an indicator of water saturation of seasonally aquiferous sediments near the riverbed and of the ice content of the base of the seasonal aquifer. The third level of heterogeneity reflects the presence or absence of a water-absorbing talik above the hydrometric alignment.
|
