The invention discloses a method for extracting a
steep slope, a steep
cliff and a scarp based on an
elevation angle extreme value, which comprises the following steps of: 1, acquiring a
digital elevation model (DEM) of a research area, and constructing a multi-direction translation model of the DEM based on matrix
convolution operation; 2, calculating a three-dimensional maximum
elevation angle (3D maxEA) and a three-dimensional minimum
elevation angle (3D minEA) of DEM data through a translation model; 3, determining the critical
terrain gradient ST of the abrupt slope, the abrupt
cliff and the scarp, comparing the relative sizes of the 3D maxEA, the-3D minEA and the ST, and extracting the
raster data of the abrupt slope, the abrupt
cliff and the scarp; and 4, extracting vector lines of the 3D maxEA and the-3D minEA which are equal, superposing area vectors of the abrupt slope, the abrupt cliff and the scarp, and extracting vector line data of the abrupt slope, the abrupt cliff and the scarp through a
cutting method. According to the abrupt slope, abrupt cliff and scarp extraction model provided by the invention, the
landform abrupt change is prevented from being smoothed, and the abrupt slope, the abrupt cliff and the scarp which are easily hidden by slope
smoothing are excavated.