Published 03.02.2021 RSE "Kazhydromet" of the Ministry of Ecology, Geology and Natural Resources of the Republic of Kazakhstan conducted an analysis of changes in the flow of the Zhem and Oyil rivers under the influence of economic activity and changing climate.
Thus, as a result of the imposition of changes in climatic factors on economic activity, the average annual flow volume in comparison with the conditional natural period in the Zhem River decreased to 201 million m3 (by 58%), along the Oyil River-to 233 million m3 (by 25%).
On the Genesis of the lowland rivers of Kazakhstan are rivers snow power, therefore, analyzed the long-term dynamics of rainfall during the winter period, according to which it is revealed that over the last 20 years, there has been a decreasing trend in precipitation. At the same time, there is an increase in the average annual air temperature in both river basins, which, in turn, leads to a shift in the dates of the beginning of the flood to earlier dates, thereby increasing the length of the low-water period.
Today, one of the most important tasks is to further investigate the causes of the reduction in the flow of small rivers and develop recommendations for the preservation of their ecosystem.
For this purpose, Kazhydromet plans to conduct expedition activities to study the current state of the Zhem and Oyil river basins and to determine the causes of flow changes.
It should be noted that hydrometric observations in the basins of the Zhem and Oyil rivers have been conducted since 1935. In the mid-50s of the last century, the average annual flow of the Zhem River was 474 million m3, in the Oyil river - 310 million m3. With the advent of dam systems for estuary irrigation and small hydraulic structures, the average annual flow decreased by 18%, and on the Zhem River was 388 million m3, Oyil-253 million m3.
Similar changes are taking place in other regions of the country. The study of such problems of small rivers, which, in turn, are feeding tributaries of large water bodies, is a primary important task not only for Kazhydromet specialists, but also for the entire scientific community in the field of water safety.