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Analysis of Long-Term Changes of a Sandy Shoreline Utilising High-Resolution Aerial Photography

Chapter
Part of the Coastal Systems and Continental Margins book series (CSCM, volume 13)

Abstract

The Wadden Sea is the shallow sedimentary coastal zone of the south-eastern North Sea. It is a highly dynamic system where shorelines are continuously changed by wind, waves, currents and tides. These morphodynamics were surveyed at the island of Sylt which is located in the northern Wadden Sea. The base of this long-term study is a series of high-resolution aerial photographs from 1928 to 2003. The analyses of the georeferenced aerial photographs and the quantification of shoreline changes were conducted with a Geographic Information System (GIS).

The northern part of the island of Sylt turned out to be the most interesting area where different coastal processes can be observed. The west shore of northern Sylt is subject to severe erosion as it is exposed to strong westerly winds, a consistent westerly wave wash and strong currents. Therefore, a considerable coastal retreat was observed here. In contrast to this, the north shore turned out to be an accumulation area. However, the east shore of northern Sylt is rather inactive due to its sheltered position as well as solid coastal protection constructions, such as dykes and petrified coastal sections.

In order to compensate the coastal retreat at the west shore, sand replenishment is carried out almost annually since 1972. By this, the loss of sand gets compensated and the shoreline could be fixed. At the same time, the annual accumulation rates at the north shore increased considerably. Due to the sand replenishment at the west shore, a lot of unconsolidated material is artificially supplied to the depositional system. These sediments get transported to some extent to the north shore of Sylt where they are deposited.

High-resolution aerial photographs and their analysis with GIS proofed to be very suitable to monitor coastal processes and the efficiency of coastal protection measures, like sand replenishment. This technique is a powerful method to detect erosion “hotspots”. It can be especially recommended for long-term and local surveys at a smaller spatial scale.

Keywords

Shoreline changes GIS Aerial photographs Wadden Sea Sand replenishment 

Notes

Acknowledgements

Christian Hass (AWI), the Regional Office of the Schleswig-Holstein Wadden Sea National Park, Toenning (NPA) and the Regional State Office for the Rural Areas, Husum (ALR) are gratefully acknowledged for providing aerial photographs. My thanks to G. Gayer from the GKSS for supplying the current model and special thanks to Trevor Vincent for proof-reading.

References

  1. Ahrendt, K. (1993). Sedimentdynamik an der Westkueste Sylts (Deutsche Bucht/Nordsee). Meyniana 45: 161–179.Google Scholar
  2. Ahrendt, K., Thiede, J. (2001). Naturraeumliche Entwicklung Sylts – Vergangenheit und Zukunft. In: Daschkeit, A., Schottes, P. (Eds.). Klimafolgen fuer Mensch und Kueste am Beispiel der Nordseeinsel Sylt. Springer, Berlin, Heidelberg, New York: 69–112.Google Scholar
  3. ALR (Amt fuer laendliche Raeume, Husum) (2007). Kuestenschutzmaßnahmen Westkueste Sylt 2007. Husum.Google Scholar
  4. Andres, F.J., Byrnes, M.R. (1991). Accuracy of shoreline change rates as determined from maps and aerial photographs. Shore and Beach (January): 17–26.Google Scholar
  5. Backhaus, J., Hartke, D., Huebner, U., Lohse, H., Mueller, A.. (1998). Hydrographie und Klima im Lister Tidebecken. In: Gaetje, C., Reise, K. (Eds.). Oekosystem Wattenmeer – Austausch-, Transport- und Stoffumwandlungsprozesse. Springer, Berlin, Heidelberg, New York: 39–54.Google Scholar
  6. Behrens, A., Gayer, G., Guenther, H., Rosenthal, W. (1997). Atlas der Stroemungen und Wasserstaende in der Sylt-Romo-Bucht. Geesthacht, GKSS Forschungszentrum.Google Scholar
  7. Boak, E.H., Turner, I.L. (2005). Shoreline definition and detection: a review. Journal of Coastal Research 21(4): 688–703.CrossRefGoogle Scholar
  8. CPSL (Coastal Protection and Sea Level Rise) (2001). Final Report of the Trilateral Working Group on Coastal Protection and Sea Level Rise. Wadden Sea Ecosystem No. 13. Common Wadden Sea Secretariat, Wilhelmshaven, Germany.Google Scholar
  9. CPSL (Coastal Protection and Sea Level Rise) (2005). Coastal Protection and Sea Level Rise – Solutions for sustainable coastal protection in the Wadden Sea region. Wadden Sea Ecosystem No. 21. Common Wadden Sea Secretariat, Trilateral Working Group on Coastal Protection and Sea Level Rise (CPSL), Wilhelmshaven, Germany.Google Scholar
  10. Dolan, R., Hayden, B.P., May, P., May, S. (1980). The reliability of shoreline change measurements from aerial photographs. Shore and Beach (October): 22–29.Google Scholar
  11. Hapke, C.J. (2005). Estimation of regional material yield from coastal landslides based on historical digital terrain modelling. Earth Surface Processes and Landforms 30: 679–697.CrossRefGoogle Scholar
  12. Landesregierung, S-H. (- Ministerium fuer laendliche Raeume, Landesplanung, Landwirtschaft und Tourismus des Landes Schleswig-Holstein) (2001). Generalplan Kuestenschutz - Integriertes Kuestenschutzmanagement in Schleswig-Holstein. Kiel.Google Scholar
  13. Landesregierung, S-H. (- Minister fuer Landwirtschaft, Umwelt und laendliche Raeume) (2007). Haushaltsmittel fuer den Kuestenschutz. Drucksache 16/1203, Schleswig-Holsteinischer Landtag, Kiel.Google Scholar
  14. Li, R., Keong, C.W., Ramcharan, E., Kjerfve, B., Willis, D. (1998). A coastal GIS for shoreline monitoring and management – case study in Malaysia. Surveying and Land Information Systems 58(3): 157–166.Google Scholar
  15. Moore, L.J., Griggs, G.B. (2002). Long-term cliff retreat and erosion hotspots along the central shores of the Monterey Bay National Marine Sanctuary. Marine Geology 181: 265–283.CrossRefGoogle Scholar
  16. Rankey, E.C., Morgan, C. (2002). Quantified rates of geomorphic change on a modern carbonate tidal flat, Bahamas. Geology 30(7): 583–586.CrossRefGoogle Scholar
  17. Thieler, E.R., Danforth, W.W. (1994). Historical shoreline mapping (I): improving techniques and reducing positioning errors. Journal of Coastal Research 10(3): 549–563.Google Scholar
  18. Wohlenberg, E. (1953). Sinkstoff, Sediment und Anwachs am Hindenburgdamm. Die Kueste 2(2): 33–94.Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  1. 1.Wadden Sea Station SyltAlfred Wegener Institute for Polar and Marine ResearchListGermany

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