Capturing the effects of the Danube River incision on the potential natural vegetation of the Donau-Auen National Park
Anna Schöpfer, BOKU - University of Natural Resources and Life Sciences, Vienna (AT)
This study investigates the effects of the incision of the Danube on the floodplain vegetation of a study site in the Donau-Auen National Park. The research questions are: (1) How has the incision of the Danube affected the physical habitat parameters of the floodplain? (2): What is the current state of the potential natural vegetation and how does it differ from the potential natural vegetation mapped in 1975? In order to assess the effect on physical habitat parameters of the floodplain vegetation, the change of groundwater table and flood characteristics over the past decades is modelled in ArcGIS based on a digital elevation model, hydrological data and floodplain aggradation as well as river incision rates. The change of the potential natural vegetation over the past 40 years is captured by mapping the present state of the potential natural vegetation of the study site and comparing it with a map from 1975. The analysis of the physical habitat parameter showed an increase of depth to groundwater of ~ 0.5 m from 1949 to 2010. Depth of inundation and flooded area during flood events decrease over the investigated time. The comparison of the two potential natural vegetation maps shows the shift of a black poplar woodland site to the next successional phase, the rest of the study site has remained in its previously mapped phase of succession. Due to the lack of hydrogemorpological disturbances no new pioneer vegetation has been initiated.