黄土区不同植被条件下的土壤抗冲性

Soil erosion resistance of different land types in Loess Plateau area.

该文以晋西黄土区刺槐林地、油松林地、农地、草地、道路边坡为研究对象,用野外实地放水冲刷的方法,以地表径流含沙量为指标,研究了不同植被条件下土壤的抗冲性,并就坡度、地被物、植物根系对土壤抗冲性的影响,以及流量和土壤抗冲性的相关性进行了探讨.研究得出不同植被条件下土壤的抗冲性为油松林地>刺槐林地>草地>道路边坡>农地.林草措施的抗冲效果与坡度密切相关,且随坡度的增大林草措施的防冲效果变小;地被物对土壤抗冲性有显著影响,没有地被物的土壤抗冲性明显小于有地被物的土壤;植物根系对土壤抗冲性的影响与冲刷水流的流量密切相关,冲刷水流的流量较小时根系对土壤抗冲性的改善效果更为突出.黄土区水土保持的关键是分散地表径流.

Using in suit artificial eroding trial, sediment yield of surface runoff was set as a measurement index to investigate the erosion resistance of different land types in Loess Plateau area, including black locust (Robinia pseudoacacia) forest stand, Chinese pine (Pinus tabulaeformis) forest stand, farmland, grass land and roadside slope. In the experiment, the effects of slope gradient, vegetation coverage and root system on erosion resistance were examined. The relativity between flow rate of surface runoff and soil erosion resistances was also discussed. The results show that: 1) the soil erosion resistances of different land types are ranked in decreasing trend as Chinese pine forest stand > black locust forest stand > grass land > roadside slope > farmland; 2) the effect of forest and/or grass on erosion control increases along with the decrease of slope gradient; 3) soil erosion resistance increases when the land is covered with vegetation; 4) the vegetation root system has an obvious function on erosion resistance in the case of small flow. Results suggest that the key factor for erosion control in Loess Plateau area is to spread around surface runoffs.