Types of Erosion and Transportation of Materials by the River Essay

Types of Erosion and Transportation of Materials by the River - Essay Example Erosion takes place hand in hand with transportation. Transportation of materials in a stream or a river starts when water overcomes friction. Material that has been set loose through erosion is then transported along the stream. There are three main processes by which water in a stream or river transports material; suspension, traction and saltation, and solution. Suspension occurs when material composed of the finest particles such as silt and clay is lifted by the turbulence of water and transported away. Rivers that are more turbulent and fast-flowing carry more suspension. This explains why a stream or river gets muddy towards its mouth. The velocity of the water is greater here. Traction and saltation occur when larger particles are carried away. Saltation refers to when a material such as gravel and pebbles that are too heavy to be carried away in suspension are bounced along by the water force. Traction, on the other hand, occurs when larger material like boulders is pushed and rolled along the river or stream bed by the force of the water. The third process, solution, occurs when materials such as minerals and dissolving rocks dissolve in the water and are carried along. This happens mostly in areas whose geology is limestone with water that is slightly acidic. Stream capacity refers to the sum capacity of residue that a stream can move, transport, or carry. Water streams carry sediment. Different streams carry different amounts of sediment. This capacity depends on the velocity and volume of water that is being channeled. Stream competence, on the other hand, refers to the sedimentary particle size that a stream can move, transport, or carry. Again, each stream has its competency for the sedimentary particle size it can move by its velocity and volume. This competency changes with changes in velocity and stream volume. Such changes are caused by a variety of topography factors and seasonal flooding.