Investigation of the soil factors showed that the aeration and water perviousness of mixed forest were better than that of pure forest.
林地土壤因子调查的结果是混交林内土壤的通气性、透水性及总孔隙度均好于纯林。
2
The article analyses the mechanism and affected range of surface settlement around by excavation perviousness, and discusses the affecting factors and the measures to control it.
Pervious cement pavement concrete is of good perviousness, it can release the problems of highway seeper and urban environment, so it is a sort of environmental protection concrete.