Coastal and deep deformations of the riverbed in the area of a damless water intake

Abstract

The paper analyzes the dynamics of planned and deep deformations on the section of the Amudarya River in the area of the damless water intake in the main structure of the Karshi Main Canal-KMC. The results of field studies of the state of the canal situation of the Amudarya River at the site of a damless water intake are studied. The course of riverbed processes in the riverbed is studied. Recommendations for improving water intake conditions have been developed. According to the results of the field survey and the study of the head section of the supply canal, the state of the Amudarya riverbed in the water intake zone was assessed. The results of surveys of the hydraulic and pumping modes of sediments of the Amudarya River in the area of the damless water intake are analyzed and summarized. The results of field studies of the canal situation of the Amudarya River in the water intake area in the Amudarya River KMC in the area of the Karshi head water intake are studied. The riverbed situation is not characterized by constant hydraulic characteristics over time for the same water flow rate, i.e. with the same water horizon marks, the flow rates may differ from each other by about half, and with the same flow rates, the horizon marks may vary up to ± 0.6 m. This is explained by the extreme instability and high mobility of the canal, and large deformations of the canal occur in a short time. The hydraulic regime of the river is characterized by a significant redistribution of speeds, depth and width of the flow. The range of their changes is within: Maximum speed >Vmax =2…5 m/s; average speed Vav = 0.5…2.5 m/s; depth H max = 4…14 m, Hav = 1…5 m; width B = 300…2000 m; slope i = 0.00016…0.0003. It is established that the characteristic feature of the river is that at a constant flow can have different average velocities depth and width, for example, when Qw = 1000 m3/s, respectively, v = 0.6…1.7m/s, B = 180…1030m, Hav = 1.1…4.3m.