【摘要】 该文通过紫色丘陵区响水滩小流域不同土地利用类型、不同坡度和坡长、不同地貌部位土壤剖面中137Cs含量的测定与分析,对其侵蚀空间分布进行了估算。研究结果表明:该流域137Cs含量的背景值为1870 Bq/m2;流域内坡耕地、林地的年平均侵蚀强度分别为4468、1759 t/(km2.a);土壤侵蚀量与坡长、坡度均指数相关;丘顶、丘坡和鞍部的年平均侵蚀强度分别为2125、4676、3625 t/(km2.a)。结果表明土地利用类型、坡长和坡度、地貌部位对土壤侵蚀量影响很大,坡耕地是该流域泥沙的主要来源。更多还原

【Abstract】 The 137Cs contents in soil profiles were analyzed under different land use types,gradients,slope lengths,and landform positions in Xiangshuitan watershed in purple hilly area.Spatial distribution of soil erosion in Xiangshuitan small watershed was estimated.Results show that the reference 137Cs content is 1870 Bq/m2.Average erosion intensity is 4468 t/(km2·a) in cultivated land and 1759 t/(km2·a) in forest land.Erosion amount is exponentially related with slope length and gradient.Average annual soil erosion intensity in hilltop,hillside and neck are 2125,4676,1759 t/(km2·a),respectively.Soil erosion is significantly influenced by the land use types,slope lengths,gradients and landform positions.The cultivated land is the chief source of sediment in Xiangshuitan watershed in the purple hilly area.更多还原