Using Landscape Evolution Models to create new catchments

Geomorphology provides the potential to design new landforms based on understandings of hydrology and sediment transport. An example of this need are post mining landscapes where large areas (hundreds of hectares) are disturbed. Post-mining landscapes require reconstruction to support an agreed landuse. The landscape also requires integration with underlying materials and surrounding unmined or undisturbed catchments with  consideration of the post-mining land use. At many sites, pre-mine landscapes with hillslope curvature are replaced with linear hillslopes. These landscapes are easy to construct and result in a surface which can be easily traversed by agricultural machinery, while the benches often rely on drainage control structures to manage runoff and resultant erosion. An alternative to linear hillslopes is to employ a catchment focus for post-mining landscape shape using an understanding of geomorphology. Here, a new method for catchment design is presented   where a computer-based Landscape Evolution Model (LEM) is used to design the post-mining landscape. The LEM employs site and material specific hydrology and erosion parameters which produce a landscape which potentially represents the geomorphological evolution of the catchment and also has a more natural appearance. Results demonstrate that a computer generated landscape produces sediment output within that of target erosion rates with low gully depths.