Natural Causes of Coastal Erosion

Natural causes of coastal erosion include:

a. Rising sea
Rise in sea level in the long term common in many places in the world. Sea level rise due to the relative decline in the face of the land (Land subsidence) or because of sea level rise is absolute. As a result of rising sea level, the shoreline may be backed slowly toward the mainland

b. Changes in sediment supply
Supply of sediment to coastal areas can be derived from the mainland (blastic sediment) or from the sea (biogenic sediment). Change in the sediment source of bias caused by the natural process of rock weathering on land or due to reduced river flow carrying sediment. Reduced sediment supply from the sea can be caused by a damaged reef areas or coral growth inhibition.

c. Storm Waves
Storm surge could cause beach erosion, this is caused by the storm occurred during the current perpendicular to the beach big enough to carry beach material. Generally the process of erosion caused by storm waves iniberlangsung in a short time and are termporer, because the eroded material will be left in the surf zone and will return to shore on a wave saait calm (swell). However, if the monitor is steep bathymetry and have trenches beach sediment carried in the unbiased back to the beach.

d. Overwash (runoff)
Overwash occurs when a high tide accompanied by high waves hit the coast passing over the tongue of sand (dune). As a result of the tongue Overwash be eroded beach sand and deposited on the inside tongue of sand.

e. Transport parallel to the beach
Selection (sorting) beach material can be changed according to the gradation of grain and circumstances of this wave resulting from wave activity. These changes may result in changes to the shoreline or beach erosion and accretion.

f. Transport by wind
Coastal erosion can be caused by sediments by wind terangkutnya land. Wind berberan in distributing sand beach in the direction parallel to the beach, where sand supply is smaller than the transport capacity then the erosion of coastal winds can occur.