"Especially in the field of hazard zone planning and flood protection there is a lot of spatial data. Rivers are surveyed and 3D models are constructed. Hydraulic simulations provide information on the dispersion of water during floods. The quality of the geodata plays an important role here. The more accurate the surveying and the hydraulic network, the more plausible the results. The results are visualised, among others, by means of geoinformation systems".