Landscape Evolution Model at the Flume Scale

Landscape evolution models (LEMs) refer to a class of models that simulate key features of network structures at the catchment scale, along with runoff and sediment deposition. Such models can reproduce landscape features as captured by different (statistical) metrics. Similarly, at the laboratory scale, LEMs produce results that are consistent with experimental data, for instance in the generation of landscape incisions. One relatively simple LEM consists of a Fokker-Planck equation accounting for surface elevation changes due to raindrop impact and shear-driven erosion due to overland flow, coupled with a flux-conserving overland flow model. In this work, this LEM was modified to account for non-uniform rainfall, and applied to laboratory data from an erosion flume subjected to intense rainfall. The experiment was designed to produce erosion from raindrop impact and sheet flow. Several detailed laser scans quantified the surface evolution. The LEM was capable of reproducing the overall surface morphology, but not its detail, since the model does not account for the small-scale morphology, which locally controls the surface flow.