It was estimated that approximately 300-400 tons of soil per annum are lost due to soil erosion by water. The intensity of soil erosion by water is mainly related to vegetation cover, surface slope, soil development and rainfall erosivity. The intensity of soil erosion by water is slight in the Great Lakes Depression, Valley of the Lakes and the eastern parts of Gobi with low mountains and depressions, which account for 92 per cent of the total areas affected by soil erosion by water. Severe soil erosion by water occurs in mountainous regions and along piedmont, especially in Mongol Altai, Gobi Altai and the Gobi-type piedmonts and southern parts of the Khangai and Khan Khukhii Mountains, which account for 4 per cent of the total areas affected by soil erosion by water.