Investigations on determination of changes in inactive volume of water reservoirs (case study of South Surkhan water reservoir)

Abstract

The article develops the change of the reservoir’s useable volume under the effect of turbidity-sediments, considering the turbid discharges' hydrological regime into the reservoir, and proposes a computation technique. Field research was conducted in the South Surkhan reservoir. Based on the data collected from the field research, an electronic map of the reservoir bowl was made, and morphometric indicators were evaluated, considering the formation of muddy sediments in the reservoir. When the standard water level of the water reservoir is 415 meters, the designed water surface area is 65 km2, and the full volume is 800 mln. m3, and according to the results of field research, the full volume of the water reservoir at the level of the normal moisture level is 491.2 mln. m3, the water surface was 72.45 km2. It showed that the full volume of the reservoir was reduced by 38.6 percent compared to the design volume during the operation period, and the water surface area increased by 7.45 km2. The research results allow to determine the change in the useful volume of the reservoir under the influence of turbidity and sediments, to determine the morphometric indicators, and to use the water reserve effectively.