This tool classifies each DEM grid cell into one of nine multiscale topographic position classes by combining local- and broad-scale maximum standardized elevation deviation (DEVmax) responses. The tool computes DEVmax internally for two user-defined scale ranges and then applies ternary thresholds to both responses. The broad-scale response separates lowland, intermediate, and upland settings, while the local-scale response separates hollow, mid-position, and knoll settings.
The combined output classes are: 0 Lowland hollow, 1 Lowland mid-position, 2 Lowland knoll, 3 Intermediate hollow, 4 Intermediate mid-position, 5 Intermediate knoll, 6 Upland hollow, 7 Upland mid-position, and 8 Upland knoll. The output raster is categorical and is intended to be displayed using a fixed nine-class palette.
The local and broad scale ranges are each defined by minimum scale, maximum scale, and step size parameters. Thresholds (local_threshold and broad_threshold) control the ternary classification of the corresponding DEVmax mosaics. The optional min_patch_size parameter can be used to suppress very small mapped patches after classification. The optional output_confidence raster stores a class confidence value in the range [0, 1] based on the margin from the classification thresholds.
Lindsay, J. B., Cockburn, J. M. H., and Russell, H. A. J. (2015). An integral image approach to performing multi-scale topographic position analysis. Geomorphology, 245, 51-61.
max_elevation_deviation, multiscale_topographic_position_image
def multiscale_topographic_position_class(self, input: Raster, local_min_scale: int = 5, local_max_scale: int = 80, local_step_size: int = 1, broad_min_scale: int = 500, broad_max_scale: int = 2000, broad_step_size: int = 20, local_threshold: float = 0.5, broad_threshold: float = 0.5, min_patch_size: int = 0, output_path: Optional[str] = None, output_confidence_path: Optional[str] = None, callback: Any = None) -> Raster: ...