ESTIMATION OF TRAP EFFICIENCY OF SRIRAMSAGAR RESERVOIR

Abstract

Reservoirs all over the world undergo the flow of sediment and deposition in it over a period of time which causes a reduction in their capacity. The estimation of sedimentation in the reservoirs has become a significant problem. There are a number of methods to estimate the sediment deposited in the reservoir. However, each method varies greatly in its own way in its complexity, inputs and other requirements. The simple way to determine the quantity of sediment deposited in the reservoir can be done through the knowledge of the trap efficiency of the reservoir. Trap efficiency (Te) is the proportion of the stream sediment that is trapped in the reservoir. Many of the trap efficiency estimation methods establishes a relationship of the trap efficiency to their capacity and annual inflow, generally through curves. In this study, the empirical relationships given by Brown, Gill and Brune were used for estimating the trap efficiency of Sriramsagar reservoir on Godavari river in Nizambad district of Telangana State, in India and compared with the observed trap efficiency of the reservoir. It is found that the trend of the results of Gill's and Brune’s method for medium sediment followed that of the observed Te and it is also observed that the results of the values of the Te estimated by the Brown's method with K=1 is found to be best suited for estimating the Te for the reservoir. It is also seen that, the major advantage of these empirical methods is to give fairly reasonable results from very limited data that is capacity, average annual inflow and catchment area.