نگاهی آماری به وضعیت فرسایش آبی در ایران

Soil erosion and its consequences are major obstacles for development of the country. On the other
hand, natural factors underlying erosion in Iran have caused Iran to have a high potential for water erosion.
Knowing the erosion conditions are very important for erosion control, but significant differences can be
observed in the presented information. Then, in this article it has been tried to present an illustrated image
of the water erosion conditions in Iran. Reviews show that professionals have declared specific erosion
rate of 16 to 25 t/h/y. In landscape of the country watersheds plan, the mean of specific erosion, total
erosion of the country and total sediment of the country have been estimated using EPM model equal to
6.94 t/h/y, 975 and 129 million tons respectively. While, using the rating curves studies, total sediment
yield has been estimated equal to 250 million tons per year. The results of erosion and sediment studies
in 38 catchments in Qazvin province, indicate the rate of 16.6 t/h/y for the mean of specific erosion.
The average sediment production of country is less than 15 t/h/y, based on the sediment measurement
in reservoirs of small dams. Therefore, accurate estimation of the sediment yield with proper methods
is necessary, since the estimated methods and the achieved values are very different. However, it can be
said that the average erosion rate of the country lies between 7 and maximum 16 t/h/y. According to the
area of Iran, soil erosion of the country would be 1.15 to 2.64 billion tons annually that is considered a
high rate of water erosion.