Use of Accumulation Basins to Reduce Silting of Reservoirs of Hydroelectric Power Plants Located on Mountain Rivers

Resumo

The effectiveness of the use of accumulation basins ordinarily used for river sediment to reduce the rate of silting of the reservoirs of hydroelectric power plants situated on mountain rivers is considered. The investigation is performed by methods of numerical hydrodynamic simulation based on the two-dimensional Saint-Venant equations and a new model of sediment transport that takes into account the fractional composition of the sediment. Using as an example a concrete reservoir located on a mountain river, it is shown that it is extraordinarily important to take into account the heterogeneity of the soil in the process of solving these types of problems. A combination of the annual hydraulic flushing of reservoirs and mechanical removal of soil from the accumulation basins together assure the required useful volume throughout the entire service life of the hydroelectric plant, though it requires the annual removal of up to 40% of the sediment discharge of the river.