Glaciers Reduction and Climate Change Impact over the Last One Century in the Mulkhura River Basin, Caucasus Mountains, Georgia

Abstract

The reduction of glaciers of Mulkhura River basin over the last century is revised in the paper. Mulkhura River basin is located on the southern slope of the central Caucasus from the Mount Bashili (4148 m) to the Mount Gistola (4860 m) and it is the main center of the contemporary glaciations in the Enguri River basin. The percentage reduction of areas of compound valley glaciers with the relation of air temperature and atmospheric precipitation is given in this paper. Also the paper considered the dynamics of the Tviberi and Tsaneri glaciers, which were the Georgia's largest glaciers at the end of the 19th century. 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 was 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 20th-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 L8 OLI/TIRS (Operational Land Imager and Thermal Infrared Sensor) taken in August 2014. In the mentioned study, except of the old topographic maps and aerial images, we used the climate information especially air temperature and precipitation data of the Mestia weather station.

Glacier change over the last century, Caucasus Mountains, Georgia, observed from old topographical maps, Landsat and ASTER satellite imagery

“…3). In 1960, the Tsaneri Glacier was still the compound-valley type glacier (without the Nageba Glacier) and its area was 28.3 ± 0.3 km 2 (Tielidze et al, 2015b) (Fig. 3b).…”

“…2b). The Landsat 2014 image shows the Tviberi degradation after 1960, when the smaller simple valley glaciers and even smaller cirque glaciers developed (Tielidze et al, 2015b) (Fig. 2c).…”

“…These studies inferred a total loss of ice area ∼ 30.1 % (from 48.5 to 33.9 km 2 ) in Dolra River basin (Tielidze et al, 2015a), ∼ 38.8 % (from 100.0 to ∼ 61.2 km 2 ) in Mulkhura River basin (Tielidze et al, 2015b); and ∼ 20.1 % (from 55.2 to 44.1 km 2 ) in Mestiachala River basin (Tielidze et al, 2015c).…”

Glaciers change over the last century, Caucasus Mountains, Georgia, observed by the old topographical maps, Landsat and ASTER satellite imagery

“…10b1). In the Landsat image of 2014 can be well seen the Tviberi degradation after 1960, when the relatively small size simple valley type of glaciers and even smaller cirque type of glaciers were occurred (Tielidze et al, 2015b) (Fig. 10c).…”