Introduction
Different landscapes, like plateaus, plains and mountains, arise as a result of different processes. They include glaciations, wind, weathering, erosion and deposition. Erosion and deposition have been termed as one of the major forces behind landscape types. Erosion usually occurs after weathering. Weathering is the process where rocks are exposed to water and air thereby altering their physical and chemical characteristics. They are broken down into sediments which are carried by erosion and later deposited elsewhere.
Erosion
Erosion refers to the transportation of sediments (pebbles, sand, colloids and silt) from one location to another. These sediments are transported once the rock material has been weathered. Agents of erosion include water, wind, waves, gravity and glaciers. The major driving agent leading to erosion is gravity. Gravity is a force that moves sediments from one place to another, usually downhill and is enhanced by gradient and stream velocity (Waugh 49).
There are human activities which affect erosion including deforestation, forest fires, construction activities and farming methods (Hobbs 39).
Types and effects of erosion
Water erosion is one of the major types of erosion. It can be depicted as a runoff where water moves over the surface, depending on how flat the land is, type of vegetation and type of soil. River erosion occurs when the water carries sediments which chip the riverbed making it deeper.
Features arising from river erosion include flood-plains, where erosion widens a valley rather than deepening it, ox- bow lakes, which refers to bends that have been cut off from the main rivers as a result of finding a new route and meanders where a river winds while eroding the outer bank and depositing in the inner bank of a bend making them more curved.
Other features formed include waterfalls and rapids. Wave erosion causes land forms ranging from headlands, sea caves, archs and stacks which form pillars of rock rising above water (Patherniades 59).
Deposition
Once erosion has occurred, sediments are deposited elsewhere. Agents of erosion deposit sediments which lead to changes in landscapes.
Types and effects of deposition
Deposition can occur as a result of wind where sediments are picked and transported by wind. Land features formed include sand dunes. Sand dunes are formed depending on direction of the wind. Glacial deposition occurs when glaciers melt and deposit sediments. Erosion by glaciers leads to formation of glacial lakes, cirques (which are depressions formed when ice cuts back into walls of mountains), hanging valleys and others.
Deposits by waves lead to formation of beaches, sandbars and spits. Wave deposition causes features ranging from tombolos (spits connecting mainlands to islands), beaches and spits (which are an extended stretch of the beach that project out to the ocean). Deposition by rivers leads to various land forms. They include deltas which refer to a flat piece of land created as a result of continued buildup and settling of sediments deposited by a river as it enters a lake, ocean or sea. Other features include flood plains and alluvial fans.
Conclusion
In conclusion, it is evident that deposition and erosion are major contributors towards the structure of landscapes. Tectonic settings and prevailing climate equally affects evolution of land forms. Erosion should be distinguished from weathering since erosion is the moving element while deposition implies ‘settling down’ of particles or sedimentation.
Works Cited
Hobbs, Joseph. World Regional Geography. USA: Cengage Learning, 2009. Print.
Patherniades, Emmanuel. Cohesive Sediments in Open Channels: Properties, Transport and Applications. United Kingdom: Elsevier Inc, 2009. Print.
Waugh, David. Geography: An Integrated Approach. United Kingdom: Nelson Thornes Ltd, 2000. Print.