European Geographical Studies

8-30

Authors: Nikolai A. Bityukov

The article is devoted to the analysis of the hydrological regime of small rivers of the Black sea coast of the Caucasus, located in the mid-mountain and low-mountain zones. Based on the GIS-technologies, maps of the distribution of high-altitude zones of these rivers' basins with hypsographic curves have been developed. For the mid-mountain zone of the Sochi Black sea region, the analysis of the hydrological regime of the Psiy river basin with a catchment area of 20.4 km2 and an average height of 664 m above sea level (a tributary of the Shakhe river) is given. To characterize the low-mountain hydrology, we consider the Kuapse river catchment area with an area of 14.6 km2 and an average height of 322 m, which flows into the Black sea. It was found that the input part of the water balance of these rivers in the form of precipitation measured at weather stations in the estuaries of rivers is understated due to the high-altitude zoning of catchments. To account the influence of this factor, the correction coefficients were calculated equal to an increase in precipitation by 4.5 % for every 100 m of elevation in the mid-mountain zone, and by 17.3 % per 100 m of elevation in the low – mountain zone. As a result of calculations for the mid-mountain zone, it was found that for r. Psii the main part of the balance is occupied by shallow-water ground nutrition – in total, it reaches 66 % with slope runoff. The total evaporation here is about 1/3 of the balance. For the low-mountain zone, the annual water balance of the Kuapse river basin is as follows: in mm of layer 3520 = 1539 + 1981 or in % 00=44.0 + 56.0. Here precipitation is spent on 44 % on runoff, and 56 % is spent on total evaporation. During the cold period, more than half of the precipitation goes to runoff, and only 45 % − to total evaporation. During the warm period, out of 1644 mm of precipitation, 533 mm (31.0 %) is spent on runoff, and the remaining 1111 mm (69.0 %) is total evaporation.

37-47

Authors: Elizbar Sh. Elizbarashvili, Mariya E. Elizbarashvili, Shalva E. Elizbarashvili, Nato B. Kutaladze

Based on the observations of 12 meteorological stations, the statistical structure of heat and cold waves in Georgia has been investigated. The average continuous, total, and longest wavelengths, the probability of their realization, the distribution area, and the repeatability period are determined. The long-term course of the total duration of the waves of heat and cold is investigated. The rate of change, the coefficient of determination and the criterion for the statistical significance of changes were estimated. The average total duration of heat waves per year in Georgia ranges from 13-20 days, with a maximum on the Black Sea coast and in the mountains. The total duration of cold waves is 10-14 days, with a maximum on the Black Sea coast, in the Colchis Lowland and on the plains of Eastern Georgia. The greatest total duration of heat waves is 40-90 days, and the greatest total duration of cold waves is 20-50 days. The continuous duration of heat waves ranges from 6-11 days and averages over the territory of about 8 days, and the duration of cold waves ranges from 6-8 days and averages 7 days, which is in good agreement with the process of transformation of air masses.

57-67

Authors: Tsisana Z. Basilashvili

The extreme events resulting from climate change are discussed: floods, decline of fresh water and land resources, draughts, crop failure, desertification, etc. The reasons causing climate change are examined, main of them being the anthropogenic increase of carbon dioxide concentration in the atmosphere. Its absorption is possible only by green vegetation through the process of photosynthesis, as a result of which large amount of oxygen is produced being a principal source of existence for all living organisms. Forest is rich in many kinds of food and medical products. It is a protector of water and land resources as well as a filter for purifying air and the water. The importance of forest cover in mountain regions is described, where it protects settlements, roads and fields from floods and mudflows, erosion processes, landslides and avalanches. Forest is regulating the water regime of mountain rivers curtailing floods and preventing them from drying up. The data are presented on the state of forest cover in Georgia and the world over. Resulting from unsystematic felling forests are becoming sparse, are losing their protective functions, thousands of plant and animal species are wiped out. In all settlements the population and local authorities must care for reforestation and afforestation that will facilitate the reproduction of animals and birds, increase in crop capacity and the development of resort-recreational, and ecotourism activities. While planting the forests useful kinds should be chosen and cutting dawn must be permitted for only elderly and sick trees and considering the amount of annual accretion. Very important is the raising of public awareness. Only the knowledge, correct education and love to the nature may save the biosphere and environment from the destruction and produce economic and social prosperity.