长江三峡重庆库区不同植被条件下土壤抗冲性研究

以长江三峡重庆库区典型针阔混交林、常绿阔叶林、毛竹林、灌木林及农地(对照)为研究对象,通过室内放水冲刷试验,分析探讨了森林表层与亚表层土壤的抗冲时间特性和坡度效应。结果表明:土壤抗冲性随冲刷时间延长而增强,表层土壤抗冲性为前5 min抗冲指数变化最为剧烈,亚表层土壤抗冲性为前3 min抗冲指数变化最为剧烈,典型林地土壤抗冲指数随时间变化特征为幂函数关系;林地土壤抗冲指数与坡度关系为xK e0.0755 0.0755,农地土壤抗冲性受坡度影响最为强烈,竹林土壤抗冲性受坡度影响最小;农地较林地土壤抗冲性明显降低,林地中,针阔混交林土壤抗冲性最强,森林有较好的抵抗土壤冲刷的作用。

Soil erosion resistance of different land type in Chongqing reservoir area of Three Gorges

Taking soil of mixed Pinus massoniana-broadleaf forest, evergreen broad-leaved forest, Phyllostachys pubescens forest, shrub forest and farmland in the upper reaches of Chongqing reservoir area of Three Gorges as a research object, the relationship between anti-scourability characteristics in layer-A, layer-AB of forest soil and scouring time, slope were studied by the flume experiment in laboratory. The results show that the anti-scourability of soil layer -A, layer-AB increased with time, and the impact index of layer-A soil erosion resistance for first five minute was the most dramatic changes, the impact index of layer-AB soil erosion resistance for first three minute was the most dramatic changes. The index of soil anti-scouribility had the great remarkable power function with time and its relation with slope was fitted by the model of K = 0.0755e^0.0755x . Slope impact on the soil of farmland was the greatest, the one of Phyllostachys pubescens forest was lightest. Soil anti-scouribility of mixed forest land was the strongest. Phyllostachys pubescens forest land was the weakest. The forest has a good resistance to soil erosion.