Figure 10
Computation of μH and μeff. (a) Landslides metrics in 2D (after52). A (blue point) and B (red point) are respectively the highest and lowest points of the initial mass. C (cyan point) is the flow front position. H0 is the initial mass maximum thickness. H and ΔL′ are respectively the difference in altitude and horizontal distance between A and C. ΔL is the length traveled by the front flow, i.e. the length of the yellow curve. θ is the mean local slope between A and C, i.e. the mean local slope of the joint yellow and green curves. The Heim’s ratio is μH = H/ΔL′, and the effective friction coefficient is μeff = tan(θ) + H0/ΔL. (b) Landslides metrics in 3D, for the topA2 scenario with δ = 10. Color code of lines and points matches (a). The white line is the deposit extent, the dashed white line is the collapse scar extent. Colorscale in the collapse geometry matches the initial mass thickness (from yellow to red). Points A and B are uniquely defined. Points C are chosen as explained in the main body of the text. The DEM is from IGN BDTopo, coordinates: WGS84, UTM20N.
