Abstract:
Dams built on rivers are subject to sediment deposition in reservoirs created on upstream and therefore provisions for extra storage in the reservoirs should be made ,,for deposition of sediment so that the benefits do not get reduced. Various traditional as well as modern reservoir sedimentation surveying mrthotis have been given and their applications in the capacity surveys of the reservoirs in Gujarat have been described. The new idea of the effect of various frequencies of echo-sounders and the behaviour of the return of the sound waves from the different sediment layers with various densities hare been presented.
Impact of different frequencies on sediment rates have been explained and it is brought out that results of sediment rates could be controversial. The need of further research in this regard is emphasised. The analysis of the silting data of reservoirs in Gujarat with reference to silting of Indian reservoirs have also been presented.