Riverbed processes in the lower reaches of the Amu Darya river in conditions of anthropogenic impact on the river flow

Abstract

The interaction of the river flow with bottom riverine forms is considered under the significant influence of anthropogenic factors leading to changes in the water regime, the riverbed process and the ecology of watercourses. The section under consideration in the lower reaches of the Amu Darya River, taking into account the nature of the influence of both hydroelectric units, is divided into three parts: the upper section – from the Tuyamuyun hydroelectric unit to the Kipchak gorge; the middle section – from the Kipchak gorge to the Takhiatash hydroelectric unit; the lower section – from the Nietbaytas hydropost to the Kyzyljar hydropost (the delta part of the Amu Darya River). The regularities of the negative impact of anthropogenic factors on the hydraulic regime and the course of riverbed processes have been studied at these sites. The scale of the impact of anthropogenic factors significantly altering the course of the riverbed process has been determined and a generalized indicator characterizing the complex of various anthropogenic loads has been developed. It shows the change in water and riverbed regimes under the influence of hydraulic engineering measures in recent years in the lower reaches of the Amu Darya River, which are still observed in the case of wandering of the stream and the occurrence of peculiar currents, as well as deigish, where the banks are not protected by structures. In places where damless water intakes are located in channels, due to the large width of the river, planned instability occurs, which complicates water supply. According to the results of the analysis of the mechanism of these phenomena, appropriate measures have been developed to improve water intakes.