Biotope Mapping of the Intertidal Zone of Heligoland (North Sea) Using Hyperspectral Remote Sensing Images

Kurzfassung

The marine nature reserve of the island of Heligoland is located in the German part of the southern North Sea and comprises a large amount of the species representative for Northern European rocky coasts. The recording of spatial changes of the major intertidal biotopes by remote sensing techniques provides a tool to assess biodiversity change and enables a synoptic view of the system. This complements detailed ground based biodiversity studies which are traditionally restricted in area and serves as basis for decisions, e.g. in coastal zone management, nature preservation, and monitoring of the water quality. In July 2002 and September 2003, two data sets of Heligoland’s coast were acquired with the hyperspectral sensor ROSIS. The data were radiometrically, atmospherically, and geometrically corrected. Based on ground truth data and detailed spectral analysis, a supervised hierarchical classification scheme was developed to classify the different major biotopes of the intertidal zone. Comparison between the 2002 and 2003 data shows the potential and the limitations of this spectral approach and suggestions for improvement are presented. The difference in results between the hyperspectral classification of the biotopes and a recent ground based biotope mapping will be discussed.