Rational management of mountain reservoirs taking into consideration changeability of suspended sediment run-off

摘要

In the river ecological system "Water catchment's area - River - Reservoir - Sea" one of the most important roles is attached to formation of river solid sediment run-off and regulation of its regimes. High silting rate as a phenomenon, characteristic of many mountain reservoirs all over the world determines the actuality of forecast for silting chronological duration and reservoir operation term. The purpose of the research is to work out a forecast estimation method for mountain reservoir silting taking into consideration granulometric differentiation of the solid material brought to a reservoir, periodicity of sediment removal taking in to consideration changeability of suspended sediment run-off. While analyzing the results of the study data on field survey of various reservoirs has been used. Relation for calculation of mountain reservoir silting has been obtained, which considers carrying away part of the sediment brought to the reservoir by river solid sediment, solid slips, landslides, mudflow, wind sediments and coast washing products in suspended condition into downstream as well as periodicity of hydraulic cleaning of reservoir sediment. Method for determining periodicity and duration of hydraulic cleaning is suggested. A method has been developed for probability evaluation of mountainous reservoir silting terms taking in to consideration changeability of suspended sediment run-off, which is based on statistical models of annual average discharges of suspended sediments. It has been ascertained that regulation of solid sediment run-off regimes in mountain reservoirs provides for the efficient management of ecological and technical system.