The influence of climatic conditions of Central Kazakhstan on the state and development of the hydrographic network of the Region

Abstract

 The climate of Kazakhstan has changed significantly during the Quaternary period. This affected the periodic  flooding or desiccation of the territory, traces of which have been preserved in the relief to this day. Focus on  climate change in the historical era (2000‒3000 years) it caused various opinions and disputes. According to  some researchers, over the past 2000‒3000 years, the climate has become more humid than in the preceding  postglacial period. Although small intra-century cycles of fluctuations in lake levels indicate periodic humidification of the climate, the general course of the centuries-old cycle is now directed towards decreasing humidity. Consequently, the drying of the territory of Kazakhstan will reach a maximum in 2600‒2700, after  which the climate will change towards humidification. The increase in moisture levels from 1952-1953 was  reflected in the rise in lake levels, increased river flows, and the onset of glaciers, which is the result of an  intrasecular rhythm of moisture variability against the background of large, centuries-old rhythms. Research  shows that in Kazakhstan, during the Quaternary, there was an alternation of pluvial and xerothermal epochs,  but the type of modern relief-forming processes is more consistent with xerothermal epochs. This is evi[1]denced by a reduction in runoff along the valleys, a partial transition of concentrated runoff to a flat one, a reduction in the water area of lakes, the presence of abandoned irrigation ditch systems far from the modern  water channel, and the death of tributaries of the right bank of the Yertys River at the level of the modern  floodplain. At the present stage, climate aridization has affected the hydrographic network of Central Kazakhstan.