Human effects on coastal landforms

years, and Britain is divided into cells, in which this sediment is usually contained and equally distributed. However due to coastal management these cells have been interrupted and the balance has been lost, the use of groynes to protect beaches from wave erosion has caused the trapping of sediment that is transported via longshore drift. Although this seems to be good for the area as it increases their defences from the effects of erosion by the sea, the trapped sediment cannot be transported to other areas in the cell, so other beaches are eroded with no supply of fresh sediment, and this can cause floods and excessive coastal erosion. The effects of this can be seen in England, the use of groynes in some areas of England has caused the dramatic erosion of beaches elsewhere, and now cliff bases are exposed to erosion causing the collapse of the cliffs and settlements that exist on them. In the area of Dawlish Warren in Devon, coastal management reduced the amount of sediment contributing to the spit in the Exe estuary and it began to shrink, the removal of this landform would have had devastating effects on the surrounding area, such as floods and the destruction of a harbour. To protect the spit and the nature reserve which exists on it, a management scheme build coastal defences. Although these protect the area these defences are expensive to maintain and will have effects on other areas of the coast. Other effects humans have on the coasts are the erosion and destruction of sand dunes. Sand dunes are the best natural defence from the erosive power of the sea, and take years to form. The over use of sand dunes by leisure activities can lead to their destruction. Activities such as rambling, horse riding and off road vehicles can compact the sand destroying the roots of the grass and plants that hold the dunes together, leaving them exposed to erosion by the sea or the wind, interrupting the succession of vegetation in the area. These problems have occurred at Studland Bay in Dorset, persistent leisure activities have led to the erosion of a substantial part of the sand dunes and management schemes have been set up to protect the area. Also the bulldozing of sand dunes has been know to increase sea views for surrounding houses, this leads to over-wash flooding during storms. The use of rivers as a means of transport has led to the erosion of some coasts. The dredging of navigation channels and the discharging of material in deep water to enable larger ships to travel through water channels removes sediment from coastal systems leaving the area susceptible to erosion. It will also interfere with longshore drift, which will prevent the maintenance of beech landforms such as spits. During the 18th and 19th centuries shingle from Spurn Head spit in the Humber estuary was used by whalers as ballast, leaving only sand, which was easily eroded by the wind and sea, due to the lack of sediment the split was weakened and during a storm the spit broke and the surrounding area was flooded. This is a prime example that human coastal management is dangerous. We as a people do not yet know the full reaction of our actions, and small change on an estuary may not only affect Britain but possibly Europe, and before we try to counter act nature or our own mistakes, we need to find a better understanding of coastal geology and what effects our management has on our country.