A grid-based physical model to analyze the stability of slope unit.

Grid cells and slope units are commonly used in regional landslide analysis models. In practice, both show significant advantages and disadvantages. Due to the simplicity of using regular grid cells, grid cells are favored in landslide analysis models but cannot reflect the boundary of natural slopes and landforms. Slope unit can reflect characteristics of a natural slope. The algorithm of slope stability analysis needs to iteratively calculate the safety factor of each dangerous slip surface, which is more complicated than the stability analysis method of grid cells. To this end, the failure area ratio (r A) of the slope unit, which represents the size of the failure area inside the slope unit under the rainfall infiltration, is employed to establish our landslide analysis model. In this model, larger r A can indicate a greater unstable probability of the slope unit, which is used to identify whether a slope unit is stable or not. Taking the rainfall data provided by Chongqing Meteorological Bureau as inputs, the landslide analysis model was tested in Fengjie County, Chongqing. Results show that the spatial distribution of the predicted landslides has a good correspondence with the observed landslides. The rate of false negative and false positive of the proposed model is 12.3% and 24.3%, and the accuracy of the model is 78.3%. [Display omitted] • The failure area ratio of a slope unit is used to establish a physics-based landslide analysis model. • The model was operated by the integration analysis of slope units and grid cells. • The model overcomes shortcomings of only using grid cell or slope unit in landslide analysis. [ABSTRACT FROM AUTHOR]