Clustering of flood-aggravating pathways in the forelands of Pre-Alpine Region

Upper Bavaria has comparatively higher mean rainfall amounts than other regions in Germany when the long-term rainfall data analyzed. Those heavy rainfall events cause severe human and economic impacts in the region. However, when the precipitation patterns (i.e. intensity, duration, etc.) were examined for this region, it is possible to see that similar rainfall patterns might cause different impacts in different districts of Oberland. This situation underlines the importance of understanding the different aggravating pathways of heavy rainfall events in the region. For this aim, flood-aggravating pathways such as topographic features, land use types, soil moisture and infiltration properties of the events in Oberland between the years 2001-2021 were analyzed. To determine the dominant influencing mechanisms, aggravating pathway factors are classified using hierarchical clustering for the study area. The classification results are compared with the heavy rainfall events defined by the German Weather Service (DWD), Catalogue of Radar-based Heavy Rainfall Events (CatRaRE catalogue) in terms of precipitation duration and amount, as well as fire brigade operations in the area regarding the impacts.

Herewith, direct or indirect relevance of rainfall patterns and catchment properties on the flood events in Oberland (Upper Bavaria), Germany between the years 2001 and 2021 are investigated with this study. The outcomes could provide beneficial information on different aggravating mechanisms in different districts in Oberland and could be used for future land-use planning and flood risk prevention studies.