Characteristics Of Soil Erosion On The Side Slope Of Constructing Expressway From Tongxin To Guyuan

To study the characteristics of soil erosion on the side slope of constructing expressway, segment from Tongxin to Guyuan of Yinwu expressway is selected as the research object.Using the field survey along expressway and building field experimental plots to analyse expressway soil erosion characteristic and law of soil erosion occurrence and development on the side slope of expressway.The mostly conclusion is as below:(1) The intensity of average slope soil erosion of all expressway route from Tongxin to Guyuan are 91581.10t/(km2.a),largely ahead of average soil erosion of Guyuan city.(2) The main fators influending slpoe surface erosion are rainfall amount and rainfall intensity, and there is a notable positive correlation between them. Regression equations can be drawn for soil erosion amount and principal component of rainfall factors.The regression equations are as the following: Plotâ… Y=0.183X(1)+0.093X(2)-0.255 Plotâ…¡Y=0.186X(1)+0.100X(2)-0.253 Plotâ…¢Y=0.179X(1)+0.113X(2)-0.255 Plotâ…£Y=0.210X(1)+0.103X(2)-0.252 Plotâ…¤Y=0.217X(1)+0.096X(2)-0.250 Plotâ…¥Y=0.189X(1)+0.096X(2)-0.254Vegetation plays an important role in reducing soil erosion amount.Amount of surface erosion of Ammopiptanthus mongolicus+ Agropyron cristatum+ Medicago sativa are at least, the second are Caragana korshinskii + Medicago sativa+ Amorpha fruticosa, the third are Caragana korshinskii+ Nitraria+ Medicago sativa, that of Nitraria+ Ammopiptanthus mongolicus+ Medicago sativa are maximum.(3) The amount of gully erosion and the rainfall amount efficiently are kept with the rainfall amount efficiently in a certain extent.When the average intensity of rainfall exceed 9.47 mm/h,gully erosion is likely to happen.And the bigger the average intensity of rainfall is, the more the gully erosion is produced. Under certain average intensity of rainfall,the more the rainfall amount is, the more the gully erosion is.The eroded valley on the slopes of dump area developed acutely,where the amount of gully erosion reached 9779.55 t/km2 during a rainy season.The measure of hexagon brick can prevent the eroded valley from happening. The preventive measures of arch beam can control the development of eroded valley.Combining them with vegetation measures,the slopes can be defended better.