Effects of grid coarsening on coupled hydrosystem models

M.Sc. Bastian Waldowski, Prof. Dr. Insa Neuweiler

In cooperation with: DFG research unit FOR2131

In terrestrial modeling, the interconnectedness of different compartments makes it advisable to use an integrated approach. However, coupled surface-subsurface modelling at a large scale can be very computationally demanding. This is commonly compensated by a higher grid size (compared to a stand-alone model), which may reduce model accuracy significantly due to smoothening of soil heterogeneities as well as topography. A coarser spatial grid generally leads to a decrease in curvature of the surface, which results in an underestimation of lateral fluxes.

Using the Terrestrial Systems Modeling Platform (TerrSysMP), the effects of smoothening of topography are investigated and evaluated. Further, we investigate approaches to compensate effects that come from non-resolved structures in the coarse models.