Storm Surges and East Frisian Island Sand Loss
Winter season's first storm surges have caused minor sand erosion on select East Frisian islands. Notable sand losses occurred on Juist, Norderney, Langeoog, Spiekeroog, and Wangerooge islands. The Lower Saxony State Agency for Water Management, Coastal Defence, and Nature Conservation released an interim report outlining these losses.
Coastal protection authorities are keeping an eye on sand erosion on north-east dunes on Wangerooge Island, though losses were not as severe as in previous storm surges. Current dune width and height ensure there's no immediate need for action, according to Frank Thorenz, NLWKN's island protection head.
Langeoog Island's sand deposit experienced break-offs with a depth of five to ten meters. However, around 70% of the weather body remains functional. Juist's storm surges led to some dune erosion, while Norderney's Kugelbake area saw sand removed from its recently reinforced dune section.
Storm surges impact a broad ecosystem beyond mere sand loss. They can harm NATURA 2000 sites and other coastal ecosystems, especially nature reserves along the Lower Saxony coast. Hopefully, civil protection measures will be put in place to safeguard these habitats and prevent further erosion.
Understanding Storm Surge Impact
- Erosion and Sand Loss: Storm surges can lead to inundated beaches and strong undertow currents, evacuating sand to the upper shoreface, sometimes offshore. Deficiencies in sediment accumulation affect beaches in regions like Spiekeroog Island's western tip.
- Dune Erosion: Dune toe erosions occur at about 1.5 meters above Mean High Water (MHW) and are common during significant storm surges due to frequent exposure to erosive conditions.
Action Necessary for Coastal Protection and Habitat Preservation
- Structural Measures: The use of groins, masonry protection walls, and natural barriers like dune systems contributes to mitigating erosion, providing stability to dunes, and protecting coastal communities.
- Non-Structural Measures: Dune restoration and periodic beach nourishment aid in rehabilitating damaged dunes, providing a protective barrier, and replenishing sand lost during storm surges.
- Adaptive Management: Regular monitoring of coastal conditions, adapting management strategies based on changes observed, and integrating trilateral management instruments help maintain the fragile coastal ecosystem while managing escalating pressures from human activities.
In conclusion, the impacts of storm surges on East Frisian Islands are more than just sand loss. It's a call to action for coastal communities and authorities to actively protect these islands from storm surges and other climate change implications. Integrating various protective measures and adaptive management will play a vital role in safeguarding habitats and responsibly using shared coastal zones.
Source: dpa.com
[1] Memorial University: Surf Zone and Bottom Currents.
[2] Oliveira et al. (2004): Coastal Erosion and Protection Measures in the Wadden Sea Region.
[5] European Union: Trilateral Cooperation in the Wadden Sea.
