黄土丘陵林区开垦地土壤侵蚀强度时间变化研究

以黄土丘陵林区１０ａ径流泥沙观察资料为基础，分析了林地开垦后不同侵蚀年限情况下土壤侵蚀强度的变化。结果发现，随侵蚀年限的增长，土壤侵蚀强度呈明显的增长趋势，平均每年约有１０ｍｍ的土层被侵蚀掉，到侵蚀的第１０ａ时，已有１００．８１ｍｍ的土层被侵蚀掉，相当于林地土壤的Ａ层大部分遭到流失。土壤侵蚀强度的增加，土壤质量的下降，土壤性状的恶化，更促使侵蚀程强度的加剧。

Temporal Change of Soil Erosion Intensity of Reclaimed Lands in Loess Hilly Forest Region

Using the 10 years observed data about runoff and sediment in the loess hilly forest region, the temporal change of soil erosion intensity in the reclaimed lands was analy zed. The results showed that with the increasing of erosion time, the soil erosion intensity in reclaimed lands would be increased apparently, and there had about 10mm soil layer be eroded away every year. In the 10th year, the 100.81mm depth of soil was eroded away, which was almost all the humus layer. At last, it is pointed that the increase of the erosion intensity, the decease of soil quality and the worse of the soil properties would aggravate the soil erosion intensity seriously.