Measuring Soil Erosion at Different Time Intervals in Khamsan Representative Watershed using Erosion Pins

The present study was conducted to calculate the amount of erosion in monthly, quarterly, six-month and one-year time scales. Three erosion pin networks in three aspects of north, northwest and eastern slopes in control subwatershed of Khamsan representative watershed were selected in order to measure erosion during the period of October 2015 to September 2016. Due to the monthly records of erosion pins, the possibility of erosion analyzing in the intervals of less than one year (monthly, quarterly, and sixth) was used to determine the contribution of these periods in annual soil erosion. Therefore, considering pin records, the average changes in the height of the soil and, finally, the average amount of annual erosion was calculated about 17.22 t ha-1. Also, the participation of monthly, quarterly, and six month intervals in annual erosion was calculated to be 5.81, 7.33 and 9.52 t ha-1, respectively which are about 34, 43 and 55% of annual erosion. Despite significant differences in the average amount of erosion in different time periods and their participation in annual erosion, the results of one-way ANOVA showed that the effect of time scale on soil erosion is not significant.