EFFECT OF BARRAGE , ON SEDIMENTATION OF A RIVER

Abstract

The construction of diversion structures -like barrages, across the rivers entails change in the regime of these rivers consequently affecting their hydraulic parameters and sediment transport characteristics. One of the major problems associated with it, is the shoal formation upstream of the barrage. While designing a barrage, the pond level is fixed taking into consideration the requirements of the off taking channels. Further, the waterway, crest level and the afflux being interrelated are fixed taking into account the cost of river training works and aspects related to scour downstream of the barrages. However, in the, absence of any rational approach for determining the--rrg-th--af the waterway, it is generally decided by the designer depending on his engineering intution, past experience and judgement. This subjective approach in determining the waterway of the diversion structure (Barrage) has been mainly responsible for the undesirable shoal formation. In this dissertation, an attempt has been made to determine the waterway on the basis of minimum sediment deposition upstream of the barrage. The methodology adopted in the study has been used for the available data pertaining to Bidyadharpur Barrage on the river Salandi in Orissa.