river landforms Flashcards
explain how a waterfall is created
the river will go over a section of resistant rock but then will go over some less resistant rock, then the less resistant rock will get eroded down to create a punch pool. there will then be lots of very turbulent water undercutting the softer rock due to hydraulic action and abrasion. then the rock that was originally undercut will will fall down into the plunge pool to start the process again
explain how a gorge is created
They are created when waterfalls retreat. that is when the undercut rock fills the plunge pool.
explain how a meander is made
a meander is created when the thalweg of the river slowly erodes a bend of river and making it deeper and creating a slip off slope and a river cliff
explain how an ox bow lake is created
the thalweg erodes the meander that the neck of the meander joins together. deposition seals off the old meander. The old meander then dries up and creates a ox bow scar
explain how a floodplain is created
they are made when a river floods and leaves old sediment (silt) behind. they are used for farming because the ground is very fertile.
explain how a levee is made
they can be made by either a river flooding and dropping of sediment on the banks of the river or they can be made when a river goes through an area of low energy and it deposits sediment on the banks of the river
