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基于137Cs示踪技术,结合土地利用变化数据,对黄土丘陵沟壑区羊圈沟小流域土壤侵蚀强度的演变过程进行了研究.结果表明:从20世纪80年代以来,该流域土地利用强度逐渐减弱;1980—2006年间,研究区坡耕地面积急剧下降,从94.9hm2下降到0.2hm2,乔木林地面积由0增加到51.1hm2,灌木林地面积由0增加到19.2hm2,果园林地面积由0增加到18.0hm2,荒草地面积趋于稳定,由76.9hm2增加到80.1hm2.研究期间,不同土地利用类型的土壤侵蚀强度依次为:坡耕地>灌木林地>果园林地>荒草地>乔木林地;1980、1984、1996和2006年流域土壤侵蚀强度分别为6408.9、5362.4、4903.9和3641.4t.km-2.a-1,侵蚀程度由强度变为中度.土壤侵蚀强度降低的主要原因是该区的水保措施和植被恢复措施.
Based on the 137Cs tracing technique and the land use change data, the evolution process of soil erosion intensity in the Yangcungou small watershed in the gully region of the Loess Plateau was studied. The results show that the land use intensity of the watershed gradually weakened since the 1980s; From 1980 to 2006, the area of cultivated land decreased drastically from 94.9 hm 2 to 0.2 hm 2, the area of arbor forest increased from 0 to 51.1 hm 2, the area of shrub land increased from 0 to 19.2 hm 2, and the area of orchard increased from 0 to 18.0 hm 2 , And the area of dry grassland tended to be stable from 76.9hm2 to 80.1hm2. During the study period, the soil erosion intensities of different land use types were: sloping cropland> shrub land> orchard land> wild grassland> arbor forest land; 1980, 1984, 1996 And the soil erosion intensity of watershed in 2006 was 6408.9, 5362.4, 4903.9 and 3641.4t.km-2.a-1 respectively, the degree of erosion changed from intensity to moderate.The main reason for the decrease of soil erosion intensity was the soil conservation measures and Vegetation restoration measures.