Our understanding of combined geomorphic, pedological and ecological systems at large spatial scales is insufficient - although individual processes at small scales may be well understood (Reinhardt et al., 2010, Murray, 2009). This limited understanding is frustrating because it is at the landscape scale that our influence as humans is felt and where our policies have impact. The recent start of important observation sites (like Chicken Creek, but also the Critical Zone Observatories in the US) is expected to provide the first comprehensive sets of quantitative observations at the landscape scale. Based on such observations, hypotheses can be made and tested – with the use of initially simple models. We argue that much can be gained from the use of simple models in the study of human-bio-physical landscapes. Here, we will illustrate a few of those gains, using our simple landscape evolution model LAPSUS as a platform.