Influence of terrain factors on the motion parameters of the turning-type landslide-debris flow

According to the terrain features of landslides, the deflection-valley landslides are divided into three types, including the slope turning-type, concave turning-type and steep slope turning-type. The main terrain parameters are slope of sliding source area, slope gradient, lengthwise grade slope of valley and deflection angle. Through numerical simulation, influence of main terrain parameters on the movement parameters of deflection-valley landslides are preliminarily examined by the orthogonal analysis, the difference analysis and the analysis of variance. The results show that the apparent friction coefficient and mass-front velocity recovery coefficient are mainly affected by the topographic relief. The slope gradient has the greatest influence on the apparent friction coefficient, and the lengthwise grade slope of valley is the second, and the deflection angle is the smallest. The slope gradient and lengthwise grade slope of valley have the greatest influence on the mass-front velocity recovery coefficient, and the deflection angle is the smallest. The slope gradient is the significant factor for the equivalent friction coefficient, and the slope gradient and valley gradient are the significant factors for the mass-front velocity recovery coefficient. There is a significant nonlinear relationship among the apparent friction coefficient, the mass-front velocity recovery coefficient and the decisive terrain factors, which can be described using the quadratic function and the quadratic form function, respectively.