Evolution of rivers in the arid zone of Kazakhstan (geomorphological aspect).

Abstract

Geographical location, the variety of relief and climatic conditions of Kazakhstan have caused an uneven distribution of surface waters in its territory. Character of the hydrographic system, regime and flow of the rivers depend essentially on the latitudinal zonation of climate and landscapes. On the most part of the territory evaporation equals to the amount of precipitation. Therefore, there is a shortage of moisture in the soil and aridity roughs in the form of landscapes everywhere. Due to the shortage of moisture, especially sharply expressed in the desert and semi-desert areas, surface runoff is small, river system is sparse, and the rivers are shallow. Many rivers form independent basins of a closed flow and finish in small closed lakes, lost in the sands or its own deposits. Central Kazakhstan applies to the areas with poor hydrographic system. Surface runoff of the Central Kazakhstan is represented by rivers Ishim (upper), Selety, Shiderty, Sarysu, Nura. Modern state of the rivers is aggravated by environmental destabilization of the region.