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In this study one of the main branch of sephid-rud which is called Alamut-rud watershed , with the area of 72500 hec, and 18 subwatershed was chosen. All of the physical parameters in this watershed and in each subwatershed were measured seperatly.
EPM method was used for estimating the rate of erosion, in this method four parameters were found , respectivly:
erodibility Cofficient (?), land use Coefficient (Xa), coefficient of sensivity of rocks and soils to erodibility (Y) and average slope of watershed (I).the equation Z=Y.xa(? +1 0.5) was used for determining intensity of erosion. Then map of the erodibility was prepared . In this map , Alamut-rud watershed according to erodibility was divided to 5 classes, with using the amount of Z and equation ofWSP=T.H.?Z1.5annual average of sedimentaion in each subwatershed was calculated
The amount of sedimentation which was measured by EPM method was compared with amount of sedimentation in hydrometric stations ,it showed that, using the results of EPM method for estimating rate of erosion and sedimentation is acceppted.
Comparing results of EPM method with PSIAC method which was done by others in some parts of sephid-rud watershed showed that accuracy of EPM method is less than PSIAC method.
At last, this study showed, EPM method can be used in primary and identifying studying about soil erosion , and isn’t suitable for detail studying.