Author(s): M. A. Sattarov; Ibodzoda Kh; S. N. Rakhimov
Linked Author(s):
Keywords: Vakhsh river; Water reservoir; Normal level; Flow; Water discharge; Velocity; Turbidity; Suspended sediment; Tractional load; Nurek dam; Volume; Useful capacity; Depth; Theory; Model; Diffusion; Hydrophysics; Draw-down; Filling
Abstract: The high ground dam of Nurek Hydroelectric Power Station (310 m) and its water reservoir are a part of a cascade of 9 hydrosystems at the Vakhsh riverbed. Five of these systems are operational and 4 of them are under construction. The area, length, the average width and depth, the total and useful volumes are 98 km2,70 km, 1.2 km and 107 m, 10.5 km3 and 4.5 km3, respectively. The dead zone volume (>75%) is mainly concentrated near the dam and the lake-shaped part of the reservoir, and extends for about 30 km (Table 1). In this paper, the results of experimental measurements performed in 1972,1989,1994,2000, and 2001 are presented and generalized. The influence of the silting zone on the irrigationenergetic potential of the Nurek hydrosystem at seasonal draw down and filling of its net capacity is studied. A complex irregular regime of the reservoir silting is observed. Stable deposition of coarse particles of tractional load in the river part, moderate mobility of fine particles of suspended sediments in the direction of the lake-shaped part, and their homogeneous deposition on the reservoir bottom are observed. Curves of the silting zone growth are constructed. As a result, it is found that the principles of turbulent diffusion theory are more effective in investigations of the vertical turbidity distribution and in studies of the dynamics of the silting zone growth in the deep-water part of Nurek reservoir. On this basis, some problems of the diffusion theory of sediment transportation are formulated and solved. The results of these solutions are compared with the data of experimental observations.
Year: 2003