GIS analysis and geoinformatics
The phenomena of surface runoff and flash flood are investigated in the HiOS project using a geographical information system (GIS) and geoinformatics. For the investigation, a database with information on past flash flood events and the associated catchment properties is established. In addition, Bavaria is topographically analyzed with regard to surface runoff and flash floods using a GIS. Then potential influencing factors (e.g. slope, terrain, land use, etc.) are examined, classified and weighted by applying data mining approaches and the gathered geodata sets. Based on the results of the database evaluation and the hydrological and hydrodynamic modeling, a decision tree is developed. This decision tree questions the characteristic of the beneficial and triggering factors of surface runoff and flash floods and divides the municipal areas into hazard classes. The decision tree is then expressed in the form of query algorithms of the geographical information system. With the help of the developed GIS tool, the reference map of surface runoff and flash floods is generated for Bavaria.