Glaciers Retreat and Climate Change Effect During the Last One Century in the Mestiachala River Basin, Caucasus Mountains, Georgia

Abstract

The dynamics of glaciers of Mestiachala river basin for the last century is revised in the paper. The percentage shrinking of areas of compound valley glaciers with the relation of air temperature is given. The retreat of largest glacier of Georgia Lekhziri and shrinking of its area is revised according to the years. The height gradient and correlation between the air temperature data of the only meteorological station (Mestia) of region and air temperature data of the glacier Chalaati in 2011 is determined. The time series of air temperature for Chalaati glacier in 1906-2011 are restored by the using of transfer function. The surface ablation of Chalaati glacier is also calculated. During the study we used a 1:42 000 scale topographic maps of the 19th century, which were drawn up during the first topographic survey by using the plane-table surveying method. Also, we used the catalog of the glaciers of the southern slope of the Caucasus compiled in 1911 by a well-known researcher of the Caucasus K. Podozerskiy, which is drawn up on the basis of the 19th century maps. In order to identify the area and number of the glaciers of the 60s of the 20th century, we used the work of R. Gobejishvili – the Georgian glaciologist of the 20-21st centuries, composed on the basis of 1:50 000 scale topographic maps of 1960. The data of 2014 have been obtained by the Landsat aerial images of L5 TM (Thematic Mapper) taken in August 2014. In the mentioned study, except of the old topographic maps and aerial images we use the climate information of the Mestia weather station.