Experimental Investigation of Sediment Trap Efficiency in Reservoirs

N M T K Revel,L P G R Ranasiri,K P P Pathirana,R M C R K Rathnayake

doi:10.4038/engineer.v47i2.6863

N M T K Revel, L P G R Ranasiri + Show 2 more

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https://doi.org/10.4038/engineer.v47i2.6863

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Abstract

Reservoir sedimentation has become one of the major problems facing water resources development projects in many countries around the world. However, only a limited number of studies has been reported in this field, particularly addressing the trap efficiency of reservoirs. In addition, whatever available studies in this area also consider few parameters governing the reservoir sedimentation. As a result, the available knowledge on trap efficiency is not very well defined. Brune curve [4] has been widely used for estimating trap efficiency of reservoirs at present, but it has several limitations, as it considers only the reservoir capacity and inflow ratio for estimating trap efficiency. The objective of this study is to formulate an improved methodology in estimating reservoir sedimentation through laboratory experiments. A small-scaled laboratory model was set-up in representing a reservoir and a series of tests were conducted by varying inflow rate, inflow sediment concentration, reservoir capacity and outflow rate. The experimental results were compared with the available theories and found that they are not very much in agreement with many of the existing theories which are mostly based on limited number of parameters. A comprehensive data analysis was performed using dimensional analysis to develop an improved relationship to estimate reservoir sedimentation incorporating many parameters governing the problem. However, the applicability of the proposed method is still limited only to the reservoirs with continuous spilling condition. In addition, only one type of sediment gradation (d50) was used in the experimental runs and thus, the effect of sediment sizes is not well represented in this method. However, the relationship developed in this study could be further improved by conducting more experimental runs by varying few other parameters which are not considered in the present study. ENGINEER, Vol. 47, No.02, pp. 1-8 2014

Highlights

Reservoir sedimentation is a severe problem in managing water resources development projects in many countries around the world, as it reduces the original capacity significantly which affects the irrigation, hydropower and drinking water supply, flood control and recreational activities
Though reservoir sedimentation is becoming a major threat to engineers who are responsible in managing water resources projects at present, a limited number of studies has been reported in the field of reservoir sedimentation
This paper presents an experimental study carried out in formulating an improved methodology to estimate reservoir sedimentation

Summary

Introduction

Reservoir sedimentation is a severe problem in managing water resources development projects in many countries around the world, as it reduces the original capacity significantly which affects the irrigation, hydropower and drinking water supply, flood control and recreational activities. Due to lack of reservoir management practices such as periodical sediment flushing, reservoir sediment routing and improving catchment protection to reduce soil erosion, the sedimentation of reservoirs has becoming a major threat to many countries around the world. Though reservoir sedimentation is becoming a major threat to engineers who are responsible in managing water resources projects at present, a limited number of studies has been reported in the field of reservoir sedimentation. This paper presents an experimental study carried out in formulating an improved methodology to estimate reservoir sedimentation

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