A Comparison between the Amount of Reservoir Sediment Load Prediction

during Design Period and the Operational Period

Mohammad Sadegh Sadeghian¹, Mohammad Daneshkhah², Mohammad Heydari^3*

1. Assistant Professor, Faculty of Engineering, Islamic Azad University, Central Tehran Branch, Iran

2. Graduated at Civil Engineering Department, Faculty of Engineering, Islamic Azad University, Central Tehran Branch, Iran

3. PhD candidate, Department of Civil Engineering, Faculty of engineering, University of Malaya, Kuala Lumpur, Malaysia

* Corresponding author E-mail: m3heydariii@yahoo.com

Abstract: Sedimentation of dams in Iran is an important issue. Often the sedimentation prediction is done in different ways in dams’ design. Sometimes due to lack of data of sedimentation, the calculations lead to false results. To compare the predictions made as to whether the design is correct or not a method called Bathymetry is being used to determine the amount of sediment deposited in the reservoir in a certain period of time. The comparison between the above methods can determine whether the rate of deposition matches the anticipated design time or not? Therefore, in this paper, deposition rate obtained through Bathymetry was compared to the amount of anticipated deposition at design time in Karaj and Latian dams. So we used 40 to 45 years of operation period, which is done by echo sounder system, with the gained results during designing of Karaj dam and Latian dam. Furthermore, sedimentation rate and volume reduction percentage are evaluated in these two dams and the results were analyzed for determining sedimentation rate and also to study whether the total sediment volume during the reservoir useful life coincides calculations during designing. In the end, it showed that the Area Increment Method for the mentioned dams was not an appropriate and adequate method to distribute sediments. The data obtained by sedimentation through Bathymetry findings can be a model for other dams in Iran and worldwide.

Key words: Sediment Estimation, Sedimentation Prediction, Sediment Deposition, Area Increment Method