Percentage of surface increasing when passing from 2D to 3D-space used as a morphologic parameter. Application to the study and characterization of the Sierra Norte de Puebla geological formations (Mexico)

Various indices were proposed to measure the Digital Elevation Model roughness. In this paper, we present a calculation and definition of roughness index called PA3D which is based on the increasing of a bi-dimensional surface when passing to a three-dimensional space. This index was applied to measure the roughness of geological formation surfaces in the mountainous region of the Sierra Norte de Puebla, Mexico. Furthermore, the PA3D index lets locating unstable areas where landslides can occur.