| Besides receiving sediment from the longshore transport, it is also said that beaches receive approximately 80 to 90 percent of their sediment from rivers and estuaries. Rivers are an extremely large contributer to the sediment on beaches. One theory is that because dams on rivers block off an additional amount of sediment for the beach, that may be another cause of beach erosion. From an aerial view, it appears that the additional sediment received from a river causes the land to stick out into the ocean, which is called a delta. This is because there is extra sediment being deposited there by the river, and since that part of the coast has more sediment, it develops into more land |
