Numerical simulation of landscape evolution and water run-off on digital elevation models obtained from Pléiades

This paper illustrates how the main physical laws proposed in landscape evolution (LEMs) can be modeled by a system of three partial differential equations governing water run-off, stream incision, hill slope evolution and sedimentation. Several numerical experiments on high resolution digital elevation models (DEMs) obtained from image stereo pairs of the satellite Pléiades illustrate its potential to simulate the fine structure of the river network, and to understand the landscape morphology and its causes. They also permit to simulate plausible evolutions. The experiments on DEMs of the same site (La Réunion) are made at three different resolutions: the SRTM resolution (90 m), and then 12 m and 4 m on DEMs derived from several Pléiades pairs of the same site. The experiments show that the water run-off simulation critically depends on the DEM resolution. This justifies the use of high resolution DEMs like those that can now be produced from Pléiades pairs or triplets.