The coastal environments are defined as the areas lying at the interface between land and the sea. The area includes both the zone of shallow water within which waves are able to move sediment and the area landward of this zone including beaches, cliffs and coastal dunes. The landward zones are also affected to some degree by waves, tides and currents. This essay attempts to explain the main features of the coastal environment and movement of sediments. Also, outline the impact of human activities on coastal environments. Firstly, the key terms which are “coastal features” and “sediment movement” will be defined; the main body and the conclusion will be drawn at last.
Leopold, Wolman,& Miller (1992) discuss sediment movement or transport as set of processes that mediates between the flowing water and the channel boundary. It involves two main processes erosion which involves the removal and transport of sediment (soil particles which includes sand, silt and clay) and deposition which involves the transport and placement of sediment on the boundary. It is these processes that lead to formation of channels of any alluvial river as well as the floodplain through which it moves.On the other hand, Coastal features are the features formed when the running water meets with the land part of the system. there are several characteristics that contribute to the formation of these features for example sea waves. When water heats the banks of the river some materials get loss then transported by the running water to the position of deposition and these sediments are known as alluvium wicander (2011). These features are brought about either by erosion; features formed are called erosional coastal landforms. The other type is formed by deposition; features formed are called depositional landforms.
The waving of water onto the space land is known as swash and the moving back into the water body is known as backwash and through this process there comes in the formation of beaches (Svenndsen, 2013). Beaches extend from the outer limit of the longshore bars that are usually present to the low-tide line. In areas where longshore bars are absent, it can be regarded as coincident with the surf zone. The beach extends from low-tide line to the distinct change in slope and or material landward of the unvegetated an active zone of sediment accumulation. It may consist of sand, gravel or even mud, though sand is the most common beach material.
Apart from that, Lane (1955), Dunes are other features which form when sand is blown landward from beaches. Aeolian transport is favoured by high onshore wind speeds moving sand from thick beach deposits. Larger beaches generally supply greater quantities of sand to dunes than smaller beach surfaces. Coastal areas which receive abundant supplies of sand from rivers generally have the largest coastal dunes complexes. Dunes develop in rows parallel to the coast. The row closest to the coast is the primary dune set which receives sand from the beach. The secondary more inland dunes are maintained as sand is blown inland from the more coastal dunes.
In addition, cliffs are yet another example of coastal features. They are formed as a result of the combination of erosion and weathering. Soft rock for instance sand and clay, erode easily and create gently sloping cliffs. While hard rocks like chalk are more resistant and erodes slowly and hence they create steep cliffs.
Furthermore, caves are other examples of coastal features. These are as a result of waves that force their way into cracks in the cliff face. The water contains sand and other materials that grind away at the rock until the cracks become caves. This is facilitated by hydraulic actions.
Human activities that influence coastal environment are physical modification of habitats by either natural forces or human influence pose serious threats to coastal ecosystem integrity and these modifications are often difficult to reverse and may result from filing of interdal or subtidal.
Besides, Industrial development has altered, disturbed and destroyed coastal ecosystems including habitats many important industrial centres are situated on estuaries and in the vicinity of urban areas and parts. Many industrial activities affecting coastal environments include metal smelting and processing. Data and energy cables are numerous with similar effects to pipelines which are submerged in the seabed. This creates problems for other users.In addition, tourism is another contributing factor that influences coastal environment. This adds pollution waste and water needs of the environment. Tourist developments such as piers and other structures have been built directly on top of coral reefs. Nesting sites for endangered marine turtle have been destroyed and disturbed by large numbers of tourists on the beaches.
In conclusion many coastal environment features like the beaches have reversed their role, instead of being inhospitable place they have become the driving force behind the economic welfare. The overuses of the territory related to tourism as well as the proper beach have caused a general decrease in the contribution of sediments to the beaches with a continental or a marine origin.

References
Lane, E. (1955). The importance of fluvial morphology in Hydraulic Engineering. ASCE,1-17
Leopold, L.B., Wolman, M.G., and Miller, J.P. (1992). Fluvial processes in geomorphology. San Francisco: W.H. freeman and company.
Wicander, J. S. and Moriroe (2011). Geol. instructor edition. United states: Yolonda cossio.
Svendsen, E (2013). Essentials of geology. Fourth edition, united states of America, W.W. Norton & Company, Inc.