Relative Elevation Models

Relative Elevation Models, also called Height Above River (HAR) rasters, are rasters that are normalized to the elevation of a channel by creating a detrended DEM and subtracting it from the bare-earth DEM. They can be useful to visualize fluvial landforms that may be hard to discern from an aerial image or DEM alone.

Features such as relic stream channels, meander scrolls, head cut erosion, meander cutoffs, and floodplain surfaces are enhanced with relative elevation models and therefore easier to see than when viewing aerial photos or a standard DEM alone.

Identifying these features is very informative in channel migration and flood studies, as well as other habitat and engineering assessments.

Interact with the below applications to identify fluvial features revealed by REMs or to display the REMs with different symbology and export an image for your own area of interest to use in a GIS.

Explore the location of Montana landscapes revealed using lidar images, with the option to download the images.