Hydraulic Erosion Modeling on a Triangular Mesh

Abstract

Although hydraulic erosion modeling on a GIS terrain models has been addressed by a body of previous work, it still remains an open problem. In GIS, raster representation and triangular irregular networks (TIN) are the most commonly used surface models, because they are simple and offer implicit topological information. However, these data structures do not allow the simulation of erosion on concave terrain features, such as caves or overhangs. Other methods, more commonly used in the computational fluid dynamics, use volumetric data representation. They are able to model the 3D features, but they usually have high memory requirements and are computationally demanding. We propose a novel solution to the hydraulic erosion modeling problem that uses a triangular mesh data structure. Our framework allows for adaptive changes of the mesh resolution according to the local complexity of the terrain, which leads to lower memory requirements when compared to the volumetric approaches. Our data structure also supports the visualization of the concave 3D features, allowing the simulation and visualization of erosion on terrain elements such as tunnels or caves.