Dynamics of glaciation in the Kazakh part of Altai during 60 years

Abstract

Rates of degradation of glacierization шт the Kazakh part of Altai are considered in this paper. Analysis was performed on the basis of the degradation state (condition) in two reference years - 1950 and 2011. For year 1950, materials of aerial surveys were used while for 2011 we took the satellite LandSat pictures with resolution of 15 m. The pictures were processed by GIS-technologies (software packages МарInfo, АгсGIS, and others). At the beginning of second half of 19^th century (1950-1955) 241 glaciers were counted on the territory under investigation. Area of bare ice (without moraines in the fernau stage with total area of 14.3 km²) was equal to 60.3 km², and the ice volume – to 2.2524 km³. By 2011, quantity of small glaciers with areas less 0.1 km² reduced, especially on extreme west sides of the ranges. Since second half of 19^th century the Altai glaciers are at a stage of reducing, and the total quantity of glaciers decreased by 207 ones or by 64%. Area of the glaciers reduced from 71.4 down to 38.19 km², i.e. by 33.2 km².

Thus, for the last 60 years the total melting of many small glaciers and disintegration of large ones, reduction of areas of open parts of the glaciers, lowering of their surfaces, and, as the consequences, a contraction of ice volumes and resources were noticed in all glacier basins in the Kazakh part of Altai. And this took place due to the changes of climate conditions. As a whole for the Kazakh Altai, since middle of 1950s till the present time quantity of glaciers reduced by 64%, total area of glacierization - by 52%. If the present-day rates of degradation remain the glacierization here may disappear by end of 21^st – beginning of 22^nd centuries. At the same time, even if the current tendencies will retain there is no reasons to believe that degradation of the glacierization can result in significant reduction of river run-off as well as water resources of the Irtysh River.