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山西省属山地高原,山峦起伏,沟壑纵横,海拔高差悬殊(最高3058米、最低245米),大部分地区在1000米以上。黄土覆盖厚度一般为8—13米,部分地区为70—80米。植被覆盖率低,森林占12.7％,草地约占20％。全省水土流失面积为10万平方公里,占全省土地总面积的60％。晋西是水土流失的严重地区,水土流失的面积达3.4万平方公里,占晋西土地总面积4.8万平方公里的71％。水土流失形成的自然原因 1.地形:全省地形以山脉为主体,呈东北向西南方向扩展,北高南低,海拔高差2833米。地形坡度在10°以下的占10％,10—20°的占30％,20—30°的占30％,30—40°的占20％,40°以上的10％。晋西地区坡度在15°以上的达70—80％。坡面坡度越大,水土流失越严重,土壤肥力越低,土壤有机质含量一般为0.3—
Shanxi Province is a mountainous plateau, rolling hills, ravines aspect, altitude disparity (up to 3058 meters, a minimum of 245 meters), in most areas at more than 1,000 meters. Loess thickness is generally 8-13 meters, in some areas 70-80 meters. Vegetation coverage is low, with forests accounting for 12.7% and grasslands accounting for about 20%. The province’s soil erosion area of 100,000 square kilometers, accounting for 60% of the total land area of the province. Shanxi is a serious area of water and soil loss, with an area of 34,000 square kilometers of soil erosion and 71% of the total land area of 48,000 square kilometers in western Shanxi. Natural causes of soil erosion 1. Topography: The province’s terrain to the mountains as the main body, northeast to the southwest direction of expansion, North High South low elevation of 2833 meters. Topographic gradient of 10% below 10%, 10-20 ° 30%, 20-30 ° 30%, 30-40 ° 20%, 40 ° 10%. In Shanxi Province, the gradient reaches 70-80% above 15 °. The greater the gradient of the slope, the more serious soil erosion, the lower the soil fertility, the content of soil organic matter is generally 0.3-