Sea Level Rise, Coastal Processes and Human Response
by
John Ridgway
British Geological Survey

Models of sea-level change in northwestern Europe show that at the beginning of the Holocene, Britain was connected to mainland Europe by an extensive land bridge. This area of land has been termed Doggerland after the relatively shallow water region of the North Sea known as the Dogger Bank. For southern Britain and southern Jutland, the presence of settled groups of people has been dated to about 12, 400 BP and it can be inferred that the land area between these regions would also have been settled. Direct archaeological evidence of such settlement is rare, but bones of horse, mammoth and red deer, similar to those of the faunas of adjacent lands, and flint artefacts have been found in dredges from the North Sea, suggesting that an abundance of wildlife attracted human predators. Holocene sea-level rise between approximately 10,000 and 6000 BP must have had a pronounced effect on the population of Doggerland, forcing retreat onto mainland Europe and the British Isles. Complete separation of Britain and mainland Europe probably took place between 7000 and 6000 BP.

Sea-level rise during the first half of the Holocene was relatively rapid and coastal processes, such as tidal scour of deep valleys, have left their mark on the topography and sediments of the floor of the North Sea. There is nearshore archaeological evidence of drowned settlements and coastal processes continue to have a profound effect on human habitation and activities. Human interference in natural processes can also be significant and the effects may be difficult to predict and often unwanted.

Erosion is a constant problem in many coastal areas and is likely to become more intense with predicted sea-level rise. Society is faced with the choice of trying to defend the coastline against erosion or allowing events to follow a natural course. The former can be a very expensive and long-term commitment, but has to be considered where investment in the coastal zone is very high. However, protecting the coast in one area may have a detrimental effect elsewhere and may even have unexpected consequences in the immediate vicinity. The latter also has financial implications if there is a need to compensate land and property owners for their losses and requires long-term forecasting of coastal evolution and appropriate coastal zone management plans.

Sedimentation along the coastal zone can lead to the silting up of harbours and access routes. Dredging keeps many modern harbours open, but this in itself can lead to problems, because international agreements on the disposal of dredge material are becoming increasingly strict. In the past, sedimentation has led to the almost complete closure of many small ports, with consequent changes in the life styles and work of coastal communities. As with erosion, human interference in the natural processes of sedimentation may lead to conflicts of interest.

Examples from around the world demonstrate the difficulties associated with inappropriate development and use of the coastal zone. In the face of sea-level rise, island communities face the greatest challenges: they have less room to retreat, more limited resources, and economies that are largely dependent on the coastal zone.

Date received: July 14, 2005

Copyright © 2005 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caqy-33.