Impact of the Relief on the Territorial Distribution of the Precipitations on the Example of Samtskhe-Javakheti Region

Abstract

The climatic conditions in Samtskhe-Javakheti region differ from those in other regions of Georgia. The major reason for the diversified climate in the region is the nature of the underlying surface and altitude above from the sea level (900-3,300 m), nature of the surface jointing, alteration of ridges and valleys, vegetation cover (forest, meadow, valley, water basins) causing unequal warming of the underlying surface and intensification of the circulation processes. The vegetation cover in the region is transformed intensely under the influence of the anthropogenic factors what drastically changes the climatic conditions. Atmospheric precipitations are one of the climate-forming factors having its influence on the climate and determining the degree of humidification. The annual amount of atmospheric precipitations on the territory of Samtskhe-Javakheti varies between 400 and 1400 mm. It is minimal on Javakheti Plateau and Akhaltsikhe basin. The amount of precipitations on Javakheti Plateau first decreases and then, increases gradually at higher altitudes. In the basin of the river Paravani, at 1,400 m asl, the amount of precipitations decreases by 6-17 mm on average after each 100 m altitude, while above 1400 m asl, increases first, slightly (by 4-20 mm) and then, significantly (by 44-76 mm after each 100 m). The maximum amount of precipitations fallen in the area in one month in the cold period of the year is 202 mm, and the least amount is 0.1 mm. The distribution of precipitation on the territory of Samtskhe-Javakheti changes depending on the altitude, and at lower elevations, the amount of liquid precipitations is 75%, 18% are hard precipitations and 8% are mixed ones, while in the high-mountainous zone, these indicators are 60 %, 31 % and 9%, respectively. A decisive role in the territorial distribution of precipitations is played by the relief forms. The region is bordered by high ridges from all its sides. The ridges transform the atmospheric circulation processes and hamper a free flow of air masses. Therefore, the air masses in the region are of a descending nature, with the amount of moisture reduced in it (the condensation is limited), and as a result, the amount of precipitations on the major territory of Samtskhe-Javakheti is little. A continental type of the annual distribution of precipitations dominates all over the territory of the given region