The Microrelief Distribution Law On Steep Slope In Semiarid Loess Area In North Shaanxi Province

The microrelief lead to soil moisture heterogeneity on slop,therefore,According to microrelief in configuring vegetation is an important theory to solve the difficult restoration of vegetation on steep slop in semiarid loess area in north Shaanxi Province.Choosing He Vally in Wuqi County,Shanxi Province as research object,based on3-d laser scanner, GIS and significant to research microrelief distribution in steep slope in loess hilly and gully region.The results showed that comaring with tape measure results, the error is about5%of shallow gully length and scarp width measured by3-d laser scannerwhi,ch is satisfied for researching microrelief;The area percentage of differerent microrelief,from big to small,are gully (8.44%), platform(6.66%), shallow gully (5.00%),scarp(1.53%) and collapse(1.52%).The area percentage upper of scarp and collapse is between2%-5%,gully and shallow gully is between10%-15%,platform is between15%-20%; the area percentage of collapse,gully and shallow gully shown as sunny slope and half-sunny slope are higher than half-shaded slope and shaded slope,however,it shows an opposite result of scarp area percentage. The area percentage of scarp,gully and shallow gully increases with slope gradient,and The area percentage of collapse decrease with slope gradient. The ridge and valley shoulder line have different effection on the terrain parameter,such as area,length,slope gradient and confluence area of collapse,scarp and platform; in addition, According to microrelief in configuring vegetation, arbor and shrub vegetation can take a big proportion.