Desertification

Abstract

Because of mismanagement, Georgia is losing a lot of arable land each year. Analysis of subarid and arid territories of the South Caucasus shows that desert and semidesert landscapes are most closely bound to paleogeographical and paleogeomorphological conditions of the area and consequently with particularities of lithogenesis. Major types of arid landscapes of eastern Georgia are situated in the thick terrigenous–marine deposits (conglomerates, clays, sandstones). High salinity and gypsum content of these rocks stipulate aggressive reaction of soil that in turn results in the degradation of vegetative cover, i.e., causes desertification. Drought is a frequent visitor to the territory of eastern Georgia. During 1900–1990, about 134 (12 %) drought months were registered, air temperature rose by 4–5 °C in comparison with mean perennial, relative humidity was lower by 30 % and wind velocity 5–10 m/s. A fierce drought occurred in the summer of 2000 when the whole territory of eastern Georgia was declared a zone of ecological disaster. Only 20 % of grain crops and 5 % of the sunflower crop were harvested. Climatic changes recorded in Georgia are most clearly revealed in the nature of changing mean annual and mean monthly temperatures and precipitation. A general trend of climate warming is noted in eastern Georgia at a rate of 0.006 °С per annum. The desert presents itself a peculiar natural complex—a type of landscape which is formed under the conditions of constant or seasonal dry and hot climate. These landscapes are characterized by an unusual soil–ground component and at the same time by extremely poor aspectual composition. This chapter discusses growing desertification in Georgia.