erosion

Question 1

erosion examples

Answer 1

abrasion, corrasion, solution, cavitation, hydraulic action

Question 2

abrasion

Answer 2

wearing away of the bed and bank by the friction between the load carried by the river

Question 3

corrasion

Answer 3

major process by which rivers erode vertically and horizontally. process occurs due to the erosive action of particles carried by the river.

requires large amount of energy

Question 4

solution (corrosion)

Answer 4

occurs continuously and is independent of the discharge/ velocity of the river.

river water is slightly acidic as it absorbs CO2 from the atmosphere. As a result the river water will slowly dissolve the bed and banks of the channel and remove it in solution

Question 5

Attrition

Answer 5

rocks and pebbles collide with each other becoming more rounded

Question 6

cavitation

Answer 6

as fluids accelerate, pressure drops and may cause air bubbles to form as water “boils”

Bubbles of air subsequently implode and create tiny jets of water with high velocities. occurs mainly in rapids and waterfalls

Question 7

hydraulic action

Answer 7

force of air and water on the water on the sides of rivers + in cracks. includes the direct force of flowing water

Question 8

factors affecting erosion

Answer 8

load - heavier and sharper the load, the greater potential of erosion

velocity - the greater the velocity the greater the potential for erosion

gradient - soft, unconsolidated rocks such as sand + gravel are easily eroded

pH - rates of solution are increased when water is more acidic

human impact - deforistation, dams interfere with natural flow of the river.