Skip to main content
The Vulnerability of Sand Dunes

The Vulnerability of Sand Dunes

Our beaches and dunes are so popular that we put them under tremendous pressure. Where beaches can take a lot of coming and going, dunes are much more fragile. The tough plants that bind dunes in place are actually not suited to being walked on and die back very quickly with human trampling. The sand is then free to be blown away.



The vegetation on dunes is an essential feature in maintaining stability of the dune system. Damage to this vegetation caused by beach users treading a common path is sufficient to cause extensive instability over a large area due to the creation of vulnerable erosion routes. 

Recreational activities such as pedestrian traffic, cars, caravan parks, horse riding and scrambling can seriously damage dune vegetation and increase the rate of sand loss through wind erosion. This loss of sand reduces the overall mass of the beach and sand dune system which acts as a buffer to the sea. 

Pedestrian traffic resulting in the trampling of vegetation is the most widespread form of damage to dune systems caused by human activities. Probably the most seriously affected areas on the Irish coast are sand dunes that are subjected to unmanaged access can experience severe vegetation damage followed by soil and sediment erosion.


Through the development of networks of paths and tracks accessing the beach is where most of the damage generally occurs.  It is usually on the access routes to the beach through the development of a network of paths and tracks that most of the damage occurs.

These networks of informal paths become centre for erosion and are rapidly enlarged by the wind, eventually forming gullies and blow outs. Paths across the top of dunes are most at risk where wind speeds are higher and path slopes often steeper.

In some areas the cumulative pressures of vehicles, pedestrians, camping and sporting activities have caused serious deterioration of vegetation and increased the risk to the stability of dune systems.
 

Dune Blowouts


Blowouts are sandy bowl like depressions in a sand dune caused by the removal of sediments by wind. They tend to form when the wind erodes into patches of bear sand where there has been a reduction or damage to vegetation. At exposed sites even a few people occasionally walking across a foredune may disturb the vegetation sufficiently to initiate blowouts. 

Blowouts typically advance through various stages of development from erosional notches and hollows, to early blowouts, to large blowouts and then potentially to re-vegetating and stabilised blowouts. Where necessary, vegetation cover should be maintained either by keeping people out of the dunes or by appropriate infilling and replanting options.