在重庆南部南川市境内,按不同侵蚀强度取^137Cs样品,用于研究岩溶坡地不同侵蚀程度的土壤侵蚀强度与特征。结果表明,林草地侵蚀速率变化范围49.3t/(km^2·a)~230.5t/(km^2·a),平均侵蚀速率112.5t/(km^2·a);缓坡耕地侵蚀速率变化范围190.3~1138.4t/(km^2·a),平均565.5t/(km^2·a);陡坡耕地的侵蚀速率变化范围为452.0~3759.4t/(km^2·a),平均2264.8t/(km^2·a)。与黄土高原和紫色土区相比,岩溶区侵蚀速率较小。
Chose soil samples according to different degrees of soil erosion in karst slope to study the soil erosion rates, soil erosion intensity and its characteristics by using cesium^-137 technique in Nanchuan county, Chongqing. It is showed that the erosion rates of woodland and grassland range from 49. 3 t/(km^2·a) to 230. 5 t/(km^2·a), its mean value is 112. 56 t/(km^2·a) ;the erosion rates of cultivated profiles associated with relatively small slopes range from 190. 3 to 1 138.4 t/(km^2·a) ,its mean value is 565.5 t/(km^2·a). Nevertheless, the erosion rates of cultivated land with large slopes change from 452. 0 t/(km^2·a) to 3 759. 4 t/(km^2·a), its mean value is 2 264. 8 t/(km^2·a). Our research shows that the average thickness eroded in cultivated profiles in one year is 1.8 to 42 times as the woodland and grassland. Positive correlation exists between soil erosion rates and gradients. In addition, soil erosion rates on upside and middle sector are bigger than that of lower section in karst slopes, farming at steep slope must be responsible mostly for the the increase of soil erosion rates and the development of the rock desertification. Contrast to purple land and loess plateau, the soil erosion rates in karst region is small, but it's very dangerous because of the slow speed of weathering and pedogenesis of carbonate rock.