Rivers Flashcards
What features do you find in the upper course? (4)
Waterfalls, gorges, V-shaped valleys, interlocking spurs
What features do you find in the middle course? (3)
meanders, floodplains, oxbow lakes
What features do you find in the lower course? (4)
floodplains, mud flats, deltas, estuaries.
Where do you find a waterfall?
upper course
Where do you find interlocking spurs?
upper course
Where do you find a gorge?
upper course
Where do you find a v-shaped valley?
upper course
Where do you find an oxbow lake?
middle course
Where do you find a meander?
middle course
Where do you find floodplains?
middle course or lower course
Where do you find mud flats?
lower course
Where do you find a delta?
In the lower course, where a river empties into another body of water
Where do you find an estuary?
lower course
How is a waterfall formed?
when a river starts flowing over harder rock. The water vertically erodes the softer rock, and eventually starts undercutting the hard rock. Over time, the overhang of harder will be less and less supported, and eventually fall into a plunge pool. It will eventually retreat up[ the river.
What type of erosion happens when a waterfall retreating backwards?
Headward erosion
What is headward erosion?
When a waterfall retreats backwards up a river
What is a plunge pool?
The deep pool found at the bottom of a waterfall.
What types of erosion create a plunge pool?
Hydraulic action and abrasion
What is undercutting?
When the soft rock under the hard rock in a waterfall is eroded faster than the harder rock.
When the hard rock falls into the river what is it called?
Load
How is a gorge formed?
When a waterfall retreats backwards and leave a steep sided valley