In the dam of Bin El Ouidane , Morocco , the bathymetry studies were done , and that helped to validate the rate of sedimentation reaches the reservoir as shown in the paper below :
Article MODELLING RESERVOIR SEDIMENTATION AT BIN EL OUIDANE DAM, MOROCCO
Here you can find some results from 9 watersheds in Iran which has been published in a Persian journal, but I think you can simply use Figure 3 of the paper.
English abstract of the paper can be found in the link below: