Coastlines are often described as being in dynamic equilibrium. This means that although they are changing, changes along one stretch of coastline will be balanced by what is happening elsewhere. Nature has a way of evening out the differences. If the dynamic equilibrium is upset by human activity, however, the changes may be more than nature can overcome. This may occur, for example, when coastal management techniques, such as the building of groynes, impedes the process of longshore drift.A good illustration of this can be seen in the aerial photo above. On the left of the photo is the holiday resort of Highcliffe-on-Sea on the Dorset coast. To the right is Barton-on-Sea with lots of holiday homes and caravans visible. I visited this area last summer and took the following two photos. The first looks west along the coast towards the beach at Highcliffe...
The second, taken from almost the same spot, looks east towards Barton...
You should be able to work out a) the direction of longshore drift and b) why the residents of Barton are not happy!As we have said in class, beaches absorb wave energy and so play an important role in protecting coastlines from erosion. With the beach gone, Barton has had to adopt other, less attractive forms of coastal protection such as rock armour or 'rip rap'...
Meanwhile, up on the cliff tops, it is a waiting game for some of Barton's residents..
