revision Flashcards
what is lateral erosion
erosion that takes place sideways/horizontally
what are the 4 different types of erosion in a river
hydraulic action
abrasion
attrition
corrosion
what is hydraulic action
where the water erodes inside cracks
what is abraision
rocks hitting the banks
what is attrition
rocks hitting each other
what is corrosion
the water is slightly acidic and so reacts to any alkaline material (such as limestone), it then starts to dissolve it.
why does the river have a greater velocity downstream
the water will have less friction with the bed and the banks as they are worn smooth
why does the river have a shallower gradient downstream
the river will meander, causing the valley to be pushed and eroded into a flood plain
what is an interlocking spur
it is the pattern usually made by a small river as it finds the least resistant and energy needing route
what does a waterfall leave behind as it retreats
a gorge
how is a flood plain created
it is created when a river laterally erodes in a meander, as it erodes the outside and deposits on the inside it widens and flattens any valley.
what are the hills or any raised land called around a drainage basin
watershed
what type of erosion undercuts the waterfall
hydraulic action
what is the name of a river/stream that joins a bigger stream
tributary
what is the place where the tributary joins the main river called
confluence
what are the benefits of hard engineering
Very effective
Strong and durable
what are the disadvantages of hard engineering
Expensive
Visually unattractive
what are the benefits of soft engineering
Relatively cheap
Blends in with the natural environment
what are the disadvantages of soft engineering
May not be as long lasting or as strong
Can lead to conflict e.g. allowing certain places to flood
