Abstract:
Abstract—This paper explores the rate of sedimentation and trap efficiency empirical methods which are important regarding the performance of reservoirs. There are various empirical relations that may be sedfordetermining trap efficiency of reservoirs. Among them, Brown (1943), Churchill (1948), Brune (1953), Dendy (1974), Gill(1979), USDA-SCS (1983) and Siyam (2000) relationshipshave been used for determination of trap efficiency of Tarbela & Mangla reservoirs. The results were compared with the observed trap fficiencies. Trap efficiency (TE) equations were also developed both for Tarbela & Mangla reservoirs along with a combine equation for both of the reservoirs. Performance of the developed equations was evaluated using reservoir data. Further, by using capacity / inflow (C/I) ratio, TE and density of sediments, useful life of Tarbela reservoirwas estimated as of 51 years (up to year 2065) and of Mangla reservoir as 154 years (up to year 2168).