The characteristics as well as the correlation between runoff and erosion was studied under 3 kinds of cover conditions of bare-slope, artificial grass slope and ecological-restoration slope with 20°slope gradient by runoff scouring intensities of 9l/min. The results showed that: (1) Sediment yield which sourced from artificial grass slope and ecological-restoration slope was separately decreased by 95% and 98% than bare slope, and the runoff reduced by 20% and 50% than bare slope respectively; The infiltration rates of the two kinds of grass slope were higher than the bare slope by 38.32% to 51.10% and 114%; (2) Sediment and runoff process showed that the stable state appeared respectively at 26min, 18min and 6min under bare slope, artificial grass slope and ecological-restoration slope, the amount of runoff was bare slope> artificial grass slope > ecological-restoration slope. (3) For bare slope and artificial grass slope, the relationship between sediment and runoff, sediment and the drag coefficient which both showed a negative correlation, but the correlation which from the ecological-restoration slope wasn’t obvious, so, further studies should carry out to promote runoff-sediment relations on ecological-restoration slope.

GIS technology and fractal theory provide a powerful tools in the soil erosion study.Based on GIS and three-dimensional laser，and under rainfall intensities of 45, 90 and 130mm/h with 20°slope gradient using simulated rainfall experiment, Amount of erosion , fractal dimensions and Hydraulic parameters were studied from different slope positions, Which was up-slope mid-slope and low-slope, The results showed that the distribution of erosion along the slope was difference in different rainfall intensity. the fractal dimensions increased along the slope，It indicated that the complexity of erosion increased with slope length. Reynolds number, Froude number, Darcy-weisbach drag coefficient and the shear stress were the important hydraulic parameters to study the soil erosion process and soil erosion mechanism. They were showed the same or the opposite trend with fractal dimensions, taking into the erosion distribution and erosion development process, Dynamics of soil erosion could be further advance.

Using the compound erosion experimental device developed by ourselves, the compound erosion process simulation experiment of 35° steep slope were carried out under different combination modes of freeze-thaw, wind, rainfall. The runoff and sediment yield change process of Pisha sandstone slope under different dynamic combination environment were studied. The results show that the superposition of wind, freeze-thaw and rainfall conditions obviously promotes the occurrence of slope erosion, among which the effect of freeze-thaw increased the collapse phenomenon obviously in the erosion process.

Soil erosion processes and erosion distribution was research focus to establish distributed mathematical equation in the soil erosion areas, GIS techniques and fractal theory provide a means to advance these studies.Slope erosion patterns of bare slope was studied under rainfall intensities of 45、90 and 130mm/h with 20°slope gradient using simulated rainfall experiment. The results showed that the time of rill appeared of lower rainfall intensity was later than that of high rainfall intensity；Within the rainfall time，the rill scale expanded increased with the increasing of rainfall intensity; The erosion distribution was studied by the three-dimensional laser scanner，The trend of rill erosion deep kept roughly consistent with that of sediment; The characteristics was analyzed of slope erosion by GIS, the fractal dimension and sediment were both increased with rainfall intensity, The fractal dimension was increasing with erosion pattern complexity. So the fractal dimension is the representative of erosion complexity.