four processes of erosion:
- hydraulic action - water enter cracks in a rock and the force of the water breaks rock particles away from the river channnel
- corrasion - eroded rocks picked up by river scrape and rub against the channel, this is a very common process of eroision
- attrition - eroded rocks picked up by the river smash into each other and break into smaller fragments. Their edges also get rounded off as they rub together.
- corrosion - river water dissolves some types of rock e.g. limestone and chalk.
erosional river landforms
waterfalls suchs as high force waterfall on the river tees form when a river flows over an area of hard rock followed by an area of softer rock, the softer rock erodes more than the hard rock creating a 'step' in the river, as the water flows on the 'step' it erodes more and more of the softer rock, a steep drop is eventually created called a waterfall.
Overtime hard rock is eventually undercut by erosion and collapses to the foot of the waterfall, the hard rock then swirl around the foot and erode the softer rock by corrasion, this cretes a deep plunge pool, overtime more undercutting causes more collapsing causing the water to…