Technical Note: Water flow routing on irregular meshes

For spatial explicit hydrological modelling an algorithm was needed which works as cellular automata on irregular meshes. From literature it was found that usual algorithms applied for this purpose do not route the water flow correctly to its adjacent cells. In this study the hydraulic linking between mesh cells is done by calculating the flow cross section between the mesh cells. The flow cross sections are positioned in the centre of the mesh edges and are perpendicular to the local gradient of the digital elevation model. The presented algorithm is simple in its implementation and efficient in computation. It is shown that the proposed algorithm works correctly for different synthesised hill slope shapes.