Investigation of the Effect of Watershed Management Operations on Erosion Change and Sedimentation Class, using MPSIAC Experimental Model in Semi-Arid Regions

Soil erosion is one of the processes that directly and indirectly threatens our country's water and soil resources. Although this phenomenon is natural and it is not possible to prevent it, but it is very important to know all the erosion processes and factors that are involved in the production of sediment and the rate of erosion of watersheds. Main objective of this study is to evaluate the effects of conservation operations on the change of erosion and sedimentation class in Morid Valley Watershed in Kerman Province.

The study area is located in Darreh Morid watershed, which is located below the Halilrud basins in Baft city, central part, Kiskan village, Darreh Morid village, Kerman province. In this study, the method of recalculation of some parameters of the MPSIAC model before and after the implementation of conservation operations was used. After determining the locations of conservation operations, maps of experimental model factors were prepared before and after conservation operations, and then the amount of sediment before and after conservation operations in each sub-basin was calculated.

the amount of sediment in sub-basins 1, 2, 3 and 4 decreased from 1094.05, 697.60, 670.25 and 576.88 to 516.79, 386.70, 398.47 and 444.81 cubic meters per square kilometer, respectively. Meanwhile the amount of sediment in the whole basin reduced from 932.42 to 663.35 cubic meters per square kilometer. Regarding sedimentation class, the results showed that in sub-basins 2, 3 and 4, it was reduced from Ⅳ to Ⅲ. There is no change in sub-basin 1 and the whole basin.

After ensuring the normality of the data by Klomo-Smirnov method using descriptive statistical indices and paired t-test in SPSS17 software, the results were analyzed and significant changes were performed. The results indicated that the difference between the means is not zero and therefore the zero assumption is rejected. In other words, according to the averages, the implementation of conservation operations had a positive effect on reducing the sedimentation class and the amount of erosion, and the data had a correlation of 79%.