Erosion

definition

involves the wearing away of rocks and soil found along the river beds and banks

involves the breaking down of rock particles being carried downstream by the river why

why happen

water moves bc of the changing gradient, therefore has the potential energy

happens bc of dynamic equilibrium, channel bed will adapt to transport its load

dynamic downstream cause by

depth wetter perimeter channel roughness load size

types of erosion

abrasion (or corasion)

solution

hydraulic power

attrition

abrasion of corasion

the wearing away of beds and banks by sediment carried in the flow of river

solution

soluble particles are dissolved in the river

attrition

caused when rockes and boulders trasnported by the river bump into each other and break up to smaller particles

hydraulic power

process where water itself compresses pockets of air in cracks in beds or banks

pressure my cause cracks to widen breaking off rock

factors affecting rate of erosion

load

velocity

geology

gradient

ph

human factors

load

the heavier and shaper the load the greater the potential for erosion

velocity

greater the velocity greater the potential for erosion

geology

soft unconsolidated rocks such as sand and gravel are easily eroded. Clay however is not becasue it is so small and tends to be cohesive

gradient

increased gradient increases the rate of erosion

ph rates

rates of solution increase when water are more acidic

human factors

deforestation, dams and bridges interfere with the natural flow of river - increase the rates of erosion