AFTER THE GREAT FLOODS: SAR-DRIVEN ARCHAEOLOGY ON EXPOSED INTERTIDAL FLATS

摘要

After major storm surges in the 14th and 17th centuries, vast areas on the German North Sea coast were lost to the sea. What was left of former settlements and historical land use was buried under sediments for centuries, but when the surface layer is driven away under the permanent action of wind, currents, and waves, they appear again at the Wadden Sea surface. However, the frequent flooding and, thereby, the strong erosion of the intertidal flats make any archaeological monitoring a difficult task, so that remote sensing techniques appear to be an efficient and cost-effective instrument for any archaeological surveillance of that area. We show that high-resolution space borne Synthetic Aperture Radar (SAR) imagery with pixel sizes well below 1 m² can be used to complement archaeological surveys and that SAR images from the German TerraSAR/ TanDEM-X satellites clearly show remnants of farmhouse foundations and of former systems of ditches, dating back to the 14th and to the 16th/17th centuries. In particular, the new high-resolution TerraSAR-X acquisition mode (‘staring spotlight’) allows for the detection of various kinds of residuals of historical land use, some of which have been unknown so far.