Knowledge of the wind field near the ground is important for many relevant environmental questions. Valleys, crests, and other orthographic characteristics as well as land use influence the wind field near the ground. One possibility for quantitatively computing the influence of orthography at individual points is offered by diagnostic wind field modeling, e.g. with the model DIWIMO (SCHAEDLER, LOHMEYER, 1996).

The model can be used among other things for the following questions:

• Preparation of wind fields for dispersal models
• Estimation of the influence of planned development (landfills, dumps, expansion of built-up areas) on the wind field
• Transfer of wind statistics to locations with no existing wind measurements
• Production of synthetic wind statistics
• Production of ground wind maps (e.g. for wind energy use)

Figure 4/33a und Figure 4/33b reproduces an example of the result of a calculation with the model DIWIMO. One can recognize where the large-scale airflow near the ground is substantially altered in areas with sharp relief. This reflects on the one hand the change in wind velocity – easily recognizable from the airflow shown coming from the northwest in the central-city area of Stuttgart and the Neckar Valley – and on the other hand the change in wind direction. Thus even southwesterly wind directions arise in the Nesenbach Valley flowing into the city "cauldron" of Stuttgart.