Relative Elevation Model

QGIS
Published

February 3, 2022

A first attempt at making a relative elevation model in QGIS, following excellent tutorials by Daniel Coe.

For those not in the know, a relative elevation model (REM) is basically a standard DEM, but normalised to the elevation of a river channel so the value of a given pixel gives the height of that point above the height of the nearest part of the river channel. Or so the theory goes โ€“ the creation of an REM in practice is as much of an art as a science and you can get quite different results depending on how you go about creating the REM.

Made with 1m LiDAR-derived elevation data from Land Information New Zealand.

Itโ€™s interesting seeing the extent to which this kind of elevation data can reveal hydrological patterns that thereโ€™s no way of seeing when looking at aerial imagery:

Original tweet thread here: