~(137)Cs测定法研究不同坡面土壤侵蚀空间的分布特征

通过对短坡长农耕地坡面、沟坡、沟道坡面及复合坡面表层土壤１３７Ｃｓ 含量的测定分析，研究了这几种坡面土壤侵蚀空间分布特征。结果表明，在所有坡面上土壤侵蚀都表面为波动趋势，短坡长农耕地坡面中部侵蚀更为强烈；沟道侵蚀表现为溯源侵蚀强烈的趋势，而沟坡由于地表覆盖等因素的影响，侵蚀特征表现复杂；在复合坡面上及相同坡度、坡长的情况下，由于所处的部位不同，侵蚀量相差极大；在长时间段内，影响侵蚀变化的最主要因素是微地貌的变化。

SOIL EROSION SPACIAL DISTRIBUTION PATTERNS OF DIFFERENT SLOPES BY USING ~(137)Cs TRACER

The soil erosion spacial patterns of several slopes were studied through measuring 137 Cs in the top layer soil on the different slopes. The results show that all the soil erosion spacial distribution patterns are in fluctuant trend. The soil erosion is more severe in the middle part on the short farmland slope. The erosion pattern of the gully base show violent headward erosion. Because of the influence of vegetation cover and other factor, the erosion patterns on the gully slopes are complex. The soil erosion differs obviously with the compound slopes of the same slope gradient and slope length. In general, the main factor that influence soil erosion is the change of the microlandform in a long period.