Experimental Study On The Hydrological Effect Of Shrub Vegetation On Slope Protection Under Rainfall

Due to the complicated terrain conditions in the southwestern mountainous areas,many engineering slopes have been formed in the construction of transportation infrastructure,which has damaged the vegetation cover layer,caused the degradation of the ecosystem,and easily induced geological disasters.Engineering slope protection technology can improve the slope stability and effectively reduce the occurrence of landslides and other geological disasters,but most of them cannot provide a plant growth environment,so the ecological protection effect is poor.In order to restore the ecology,vegetation slope protection technology came into being.At present,the research on vegetation slope protection is mostly focused on the mechanical reinforcement mechanism of roots on slopes,and the hydrological effect of vegetation is little.However,the research on hydrological effects has focused on agriculture and forestry,which are concerned about soil and water conservation.There are few studies on the relationship between water absorption by plants,water content of soil covered by vegetation and substrate suction.Laboratory tests and field observations show that vegetation-covered soil can maintain a high matrix suction,and the matrix suction will affect the strength and hydraulic conductivity of the soil,so it is necessary to further understand the hydrological role of slope protection vegetation in slope stability.In this paper,the infinite slope model with shrubs is taken as the research object.The indoor artificial rainfall method is used to study the hydrological effect of the vegetation on the slope by comparing the vegetation slope with the bare slope without vegetation.In this paper,we obtained the changes of the internal water content and matrix suction of the slopes,and the role of shrubs in the rainfall diversion process.The results of the study show that: due to the water gathering effect of the shrub canopy,the vegetation slope is more prone to surface runoff;the interface between the root system of the shrub plant and the soil will become a preferential channel for rainfall infiltration,making rain infiltration faster In bare soil,but with the increase of slope,this preferential flow effect will be weakened due to the seepage along the slope direction;compared with bare slope without vegetation,the air intake value of the water and soil characteristic curve of vegetation slope is larger,the soil Pore body distribution is poorly uniform,the residual water content is greater,and the water holding capacity is stronger.