CALCULATIONS OF SEASONAL THAWING DEPTH IN DIFFERENT LANDSCAPES OF THE KOLYMA WATER-BALANCE STATION BY MEANS OF HYDROLOGICAL MODEL "HYDROGRAPH" (Part 2)
The purpose of the research is the analysis and modeling of the processes of active layer formation in mountain landscapes in the zone of continuous permafrost of the North East of Russia, Upper Kolyma River basin. The approach of estimation of heat transfer in the soil profile integrated in the distributed hydrological model “Hydrograph” is used. The Kolyma water balance station is the object of investigation. Based on the analysis of data of thawing depth measurements within the Station’s area, four types of underlying surface varying in regime and depth of thawing (0.5-1.8 m) of soil profile are distinguished. They are: rocky talus, mountain tundra, moss-lichen light forest and larch forest. The schematization of soil-vegetation profiles of referred types of underlying surface and corresponding sets of the “Hydrograph” model parameters are elaborated as the result of systematization and generalization of physical properties of soil-vegetation cover. The modeling of active layer dynamics is carried out for seven cryopedometers characterized by the combination of various types of soil, vegetation and topographical conditions for the period of 1950-1990 with daily time step. The acceptable agreement of observed and simulated values at all studied sites allows concluding that the developed systematization of soil profiles and assessed set of the model parameters are effective for simulation of active layer dynamics in various conditions of the Kolyma station.