静水条件下植物根系对紫色土的抗蚀性效应

Effect of Enhancement of Different Plant Rootson the Purple Soil Erosion Resistance Under Hydrostatic Conditions

三峡库区广泛分布的紫色土崩解造成严重的水土流失,在该区域人工构建植被是解决该问题的重要途径。以紫色土、狗牙根和多花木蓝为研究对象,通过静水崩解试验,研究不同植物根系组合下紫色土的抗蚀性能,分析紫色土的抗蚀性能与植物根系特征、侵蚀坡度的相互关系。结果表明:植物根系能显著提高紫色土的土壤平均质量直径(MWD)、抗蚀系数和抗蚀增强系数,植物根系组合的抗蚀增强效果为草灌混播>纯草本>纯灌木;紫色土的抗蚀系数随根系的根长密度、根表面积密度、根重密度的增大而增大,拟合优度在0.96以上,成显著相关关系;相同的种植条件下,累计崩解量随侵蚀坡度的增大而增大,且在崩解前期增速较快、后期增速较慢并逐渐趋于稳定。

Purple soil is widely distributed in the Three Gorges Reservoir area landslides caused by serious soil erosion and the artificial vegetation is an important way to solve the problem. This paper treated the Bermuda grass and the Indigofera amblyantha Craib in purple soil as research objects and studied the anti-erodibility of purple soil with different kinds of plant roots by conducting the hydrostatic collapse test. It analyzed the relevance between the purple oil's erosion resistance and the characteristics of plant roots and slop erosion. The results show that plant roots can significantly improve the soil MWD value,as well as the corrosion resistance coefficient and enhancement factor. Specifically,the anti-corrosion enhancements with different enhanced plant roots of combinations are Grass irrigation > Pure herbs > Pure shrub. Moreover,the purple soil erosion resistance coefficient increases with the increase of root length density,root surface area density and root weight density and the goodness of fit is more than 0.96; under the same planting conditions,the cumulative amount of disintegration increases with the increase of erosion slope and the growth of disintegration is faster in the early stage,slower in the later stage and gradually tends to be stable.