To test whether models give a good description of hydrological processes, some spatial mapping of the characteristics of wetness in the catchment is needed. One way is the observation of dynamic saturated areas, which in many small catchments, will be strongly related to the generation of fast run-off. Areas that are frequently saturated are also often strongly related to vegetation types. In this contribution, we describe mapping based on the vegetation patterns in a small catchment at the foothills of the Jizera Mountains in the Czech Republic. A Monte Carlo method is used to compare the vegetation pattern with saturation mapping using a boot method, mapping based on piezometer levels, and with the pattern of a topographic index. In the Smrzovsky Brook catchment, the vegetation communities are well correlated with the topographic index.