Survey Physical Properties of the Always Submerged Sediments in Dez Dam Reservoir Using the Field Data and the Empirical Methods Application

Sediment deposition is the principal problem affecting the useful life of reservoirs. Here we quantify the physical properties of sediments deposited in Dez dam reservoir by field investigations and empirical methods. Upon field investigation performed in the reservoir, 79 undisturbed sediment samples were taken from 12 cross sections of a 25 km of the reservoir upstream dam body where the sediments deposited have always been submerged. Results showed that grain size and bulk density of sediment deposited in the studied reach (up to 25 km upstream Dez dam body) are almost uniform and empirical methods for calculating bulk density in comparing of field data has averagely an error of 30%. This shows that the empirical methods arent capable accurately to predict bulk density of fine sediment in Dez reservoir. Analysis of the results showed that the error mostly refer bulk density calculation of the clay sediments.