4.6 Flashcards
What is the long profile of a river?
It is where the river is at either upper, middle or lower course due to them being different location but in the same river and they will all have different things in them.
What is the upper course?
The upper course is the slowest area of them all even though most people think it is the fastest area.
It had a lot of rocks in the way of the water to slow them down.
Abrasion and hydraulic action takes place a lot in these areas.
What is the middle course?
This is the part where the river gets faster and wider and deeper but still not as fast as it can be and it will start to meander quite a lot and the erosion is now horizontal.
What is the lower course?
It is the fastest of them all and it has less meanders and more just massive, wide, long, deep rivers which due to having nothing to stop them go the fastest and all the rocks are all sediment now.
Biological weathering
When things such as animals burrowing and trees roots destroy cliff sides and other places.
Freeze-thaw weathering
When the water gets in the cracks and expands by 10% and then widens the cracks on the cliffs.
Traction
This is where the big rocks will roll across the river bed-floor.
Suspension
Fine line of material carried by the river.
Slope processes
Slope creeping is where over time the area gets moist and wet and will move down the hillside very slowly. About 1 to 10 mm a year.
Slope processes are those that generate and transport soil or regolith. Both chemical and physical weathering occurs on and within slopes, and mass transport can be rapid and hazardous.
Lag time
The time it takes for a flood to happen after a downpour of rain.
Precipitation
The amount of rain dropped on an area.
Peak discharge
The highest amount of water levels in the area.
Rising limb
This is where the flood water will go to reach its climax.
Waterfall formation
The resistance rock will not erode as the less resistance rock will erode and create a fall of water into a small puddle at the bottom which will then erode into a plunge pool which is like a washing machine for water, and then it will erode backwards and then the resistant rock will fall under its weight and create a waterfall.
