Increasing Edge via Realignment

A useful illustration from the Dutch Deltaproof website in their section explaining managed retreat/realignment.

'Intertidal habitats and natural coastlines provide an important buffering function for flood protection. Habitats absorb and attenuate wave energy and in turn provide protection against flooding and prevent erosion, also during storm events. In addition, the intertidal areas move landward to a proportionately higher elevation as sea levels rise. Man-made flood defences form an obstacle for these natural processes to occur. These were constructed decades ago to prevent the flooding of low lying coastal and estuarine areas. While these constructions enabled the land to be developed or used for agriculture, hydro-morphological processes and functions of a water body were constrained. A fixed line of flood defence leads to narrowing of the intertidal area - a phenomenon known as coastal squeeze.'

Shifting Shores

The National Trust has just issued a new report on coastal erosions: Shifting Shores. It marks the increasing move towards adaptation strategies as it becomes clear that action to stop climate change is happening too slow and too late. The authors write:

'In our new report  'shifting shores – playing our part at the coast', we are calling for a bold and imaginative approach to coastline management, involving an understanding of how nature works, moving towards adaptation and away from maintaining engineered defences, where appropriate, while being sensitive to community needs.' 

I particularly enjoyed the glossary at the back, with these gems:

Managed re-alignment – allows an area that is not currently exposed to flooding by the sea to become flooded by removing frontline coastal protection. Note – can also occur as a consequence of ‘force majuere’ i.e. unmanaged re-alignment. [My emphasis]

Uncertainty – a situation where the current state of knowledge is such that the order or nature of things is not fully understood and thus absolute outcomes cannot be defined or guaranteed.

Preparing for change on the coast

2011 video from Managing Coastal Change about 'an innovative scheme to recreate salt marsh'.