1.3 River Processes and the Hjulstrom Curve Flashcards
What does the amount of energy depend on?
Height water descends, steepness
Mass of water available
What are the characteristics of a low-flow river?
Clear water
Visible riverbed
What is potential energy?
A still body of water at any point above sea level with stored energy.
The amount of kinetic energy generated is less than the amount of potential energy because of…
Overcoming friction
What is dissolved load?
Transportation of chemicals dissolved in the water
Eg calcium carbonate, dissolved when rainwater flows over limestone or chalk
What is suspended load?
Fine-grained mud and silt
Dark and murky
What is bedload?
Larger sediment transported along the riverbed, too heavy to be picked up.
What is traction?
Material rolled along the riverbed
What is saltation?
Material moved in a series of small bounces
What are three factors that affect the type and amount of sediment transported by a river?
Flow of river
Nature of riverbed and banks- flowing through loose materials, easier to pick up than over hard rock
Human intervention, concrete lined beds
What is river erosion?
The picking up and removal of material. Picking up individual rocks or wearing away.
Surplus energy from river needed to erode
What is corrasion?
Particles of rock scrape away the riverbed and banks. Can add more load.
What is abrasion?
When particles of rock erode away bare rocks resulting in a smooth surface
What is hydraulic action?
The power of water dislodging loose particles of rock from the riverbed or bank.
High flow
What is solution?
The dissolving of chemicals when a river flows over rocks such as limestone and chalk.
