Keywords

The glaciers are indivisible part of the environment and are a good indicator of the past and current climate change (Tielidze et al. 2015). Alpine glaciers are an important component of the global hydrologic cycle. Glaciers can help to regulate stream flows in regions where water is stored during cold wet times of the year and later released as melt water runoff during warm dry conditions (Beniston 2003; Earl and Gardner 2016). The most serious impact of vanishing mountain glaciers undoubtedly concerns the water cycle from regional to global scales. Glacier melting will probably dominate sea level rise during our century (Meier et al. 2007).

Distribution and diversity of glaciers on the Earth determine their grouping in separate regions by foreseen of the external conditions of existence of glaciers. Such zoning allows us to better understand the characteristics of glaciers’ regime and the synchronism of their action in different regions, as well as to relate the distribution of glaciers to the general circulation of the atmosphere and the relief orography.

Nineteen regions have been distinguished on the Earth based on Randolph Glacier Inventory (RGI) (Pfeffer et al. 2014), which is intended for the estimation of total ice volumes and glacier mass changes at global and large regional scales. It is supplemental to the Global Land Ice Measurements from Space initiative (GLIMS). Production of the RGI was motivated by the preparation of the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC AR5) (GLIMS Technical Report). As a result of the mentioned inventory, the Caucasus is presented together with the Middle East (as one region) (Fig. 1.1), but the Caucasus is much larger than the Middle East by the modern glaciation size and it will be interesting if we consider it as a separate region in our work.

Fig. 1.1
figure 1

First-order regions of the Randolph Glacier Inventory (version 4.0). 1. Alaska; 2. Western Canada and US; 3. Arctic Canada North; 4. Arctic Canada South; 5. Greenland Periphery; 6. Iceland; 7. Svalbard; 8. Scandinavia; 9. Russian Arctic; 10. North Asia; 11. Central Europe; 12. Caucasus and Middle East; 13. Central Asia; 14. South Asia West; 15. South Asia East; 16. Low Latitudes; 17. Southern Andes; 18. New Zealand; 19. Antarctic and Subantarctic (Pfeffer et al. 2014)

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The Caucasus Mountains are aligned west-northwest to east-southeast between 40–44° N and 40–49° E and span the borders of Russia, Georgia, Armenia, and Azerbaijan. They consist of two separate mountain systems: the Greater Caucasus extends for ~1300 km between the Black Sea and Caspian Sea, whilst the Lesser Caucasus runs parallel but approximately 100 km to the south. The Caucasus Mountains originate from collision between the Arabian plate to the south and the Eurasian plate to the north and the region is tectonically active with numerous small earthquakes (Stokes 2011).

According to location the Greater Caucasus is divided into three parts: Western, Central, and Eastern. The borderline among them runs near the meridians of the Mount Elbrus (5642 m) and the Mount Kazbegi (5033 m). In the mountainous system of Caucasus the highest is the Central Caucasus. Several peaks are higher than 5000 m (e.g. Elbrus, Dikhtau, Shkhara massif, and Kazbegi). It is in this section the Europe’s highest peak Elbrus (5642 m) with its glacial complex.

The Caucasus Mountains are characterized by strong longitudinal gradients that produce a maritime climate in the west and a more continental climate in the east. Trends in precipitation, for example, reveal that westernmost areas typically receive around three to four times as much as eastern areas (Horvath and Field 1975). The southern slopes are also characterized by higher temperatures and precipitation, which can be up to 3000–4000 mm in the southwest (Volodicheva 2002). Much of this precipitation falls as snow, especially on windward slopes of the western Greater Caucasus, which are subjected to moist air masses sourced from the Black Sea (Stokes 2011).

According to the conditions of relief, the northern slope of the Caucasus is more favorable for formation of glaciers than the southern one. This is contributed by high hypsometry and extremely partitioned slopes, gorges, and depressions, represented by wide cirques of Wurm period.

In the Caucasus the current number of glaciation is ~2000 with a total area of ~1100 km2 and volume ~68 km3 (Radić et al. 2014). Approximately 33% of the glaciers of the Caucasus is located in Georgia (Fig. 1.2). These Glaciers are an important source of water for agricultural production in Georgia, and runoff in large glacially fed rivers (Kodori, Enguri, Rioni, Tskhenistskali, and Nenskra) supplies several hydroelectric power stations. Glacial melt waters are one of the main factors in river runoff formation in the mountainous areas of Georgia. It is necessary to know Glacial waters daily volatility for mountaineering, tourism and mountainous areas of livestock and other sectors of operation. Glacier melt water is also important in terms of water supply in the mountainous regions of Georgia. In the mountainous regions (Svaneti, Kazbegi, Racha, and Abkhazeti), in addition to the tourist—recreational purposes, a great role owned the glacial landscapes in the development of the recreational facilities.

Fig. 1.2
figure 2

Georgian Caucasus glacier outlines (in yellow) derived from Landsat 8 and ASTER imagery. White rims show the individual river basins

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Also glacier outburst floods and related debris flows are a significant hazard in Georgia and in the Caucasus (Bogatikov et al. 2003). Unfortunately, such hazards are relatively common in this region and have led to major loss of life. In September 20 of 2002, for example, Kolka Glacier (North Ossetia) catastrophic ice-debris flow killed over 100 people (Evans et al. 2009), and in May 17 of 2014, Devdoraki Glacier (Georgia) catastrophic rock–ice avalanche and glacial mudflow killed nine people. Future trends in glaciers variations are thus a topic of considerable interest to the region.