The Effects of Human Activity on Coastal Landforms

The Effects of Human Activity on Coastal Landforms

Human activities add another layer of complexity to the natural

processes of coastal lands and materials. These activities may have

direct or indirect effects on our changing coastlines. They may effect

sources of new sediment to the coast and the movement of sediment

within the coastal environment.

Sediment starvation caused by river and coastal management is one

effect of human activities on the coast. For some coastal regions,

such as the Pacific coast, a large part of their sediment is supplied

by rivers. Dams built for flood control and water catchment along the

rivers leading to these coasts inhibit the transport of large grained

sediment, The coasts lack new material so erode and move inland. For

instance damming of the tributary rivers to the Mississippi River over

the past 60 years has reduced the movement of sediment. Studies in

recent years have demonstrated that the amount of sediment carried by

the Mississippi has been cut in half, aggravating the deterioration of

Louisiana's wetlands. An important source of sediment to Louisiana's

delta wetlands was periodic flooding of the Mississippi River, which

deposits new material on the flood plain. Massive levees built along

the river bans now contain these floods and eliminate the supply of

sediment to the wetlands. As a results, the natural compaction and

subsidence of the delta are no longer balanced by the deposition of

new sediments, and the local relative sea level is rising as much as

1cm per year.

Human actions can also lead to the destruction of dune grasses and the

disturbance of coastal landforms promotes inc...

... middle of paper ...

... 7000 containers. However, if this proposal is

to go ahead, it will lead to the total loss of the foreshore mudflats

and grazing marsh. There will also need to be dredging of the channel,

which will cause coastal erosion, redistribution of sediments and

variation of the channel's usual flow.

The main problem with human activity and the coasts is that human

activities often conducted without an adequate understanding of

coastal geology and process. The effects of damming the Mississippi is

a good example. So that even human activities intended to save or

improve the coast may inadvertently cause erosion. More investigations

need to be carried out on proposed developments such as Dibden Port

and the effect it will have on the coast before they are allowed to be

carried out to stop such problems occurring in the future.