This tool can be used to calculate the elevation of each grid cell in a raster above the nearest stream cell, measured along the straight-line distance. This terrain index, a measure of relative topographic position, is related to the 'height above drainage' (HAND), as described by Renno et al. (2008). HAND is generally estimated with distances measured along drainage flow-paths, which can be calculated using the elevation_above_stream tool. The user must specify the name of an input digital elevation model (dem
) and streams raster (streams
). Stream cells are designated in this raster as all non-zero values. The output of this tool, along with the downslope_distance_to_stream tool, can be useful for preliminary flood plain mapping when combined with high-accuracy DEM data.
The difference between elevation_above_stream and elevation_above_stream_euclidean is that the former calculates distances along drainage flow-paths while the latter calculates straight-line distances to streams channels.
Renno, C. D., Nobre, A. D., Cuartas, L. A., Soares, J. V., Hodnett, M. G., Tomasella, J., & Waterloo, M. J. (2008). HAND, a new terrain descriptor using SRTM-DEM: Mapping terra-firme rainforest environments in Amazonia. Remote Sensing of Environment, 112(9), 3469-3481.
elevation_above_stream, downslope_distance_to_stream, ElevAbovePit
def elevation_above_stream_euclidean(self, dem: Raster, streams: Raster) -> Raster: ...