Rivers etc. Flashcards
In which erosional landform does differential erosion occur?
Headlands and Bays
A meander is…
curves in the middle-lower course of a river
What processes occurs on the outside of a bend and why?
-erosion and deposition
-caused by the fastest flowing water hitting it
What processes occurs on the inside of a bend and why?
-Deposition
-occurs on the inside of the bend due to the water being forced to slow down
Why does the neck of a meander eventually break through?
Floodwaters cause the neck of the meander to break through
as the force of the water erodes the neck
and creates a new, straighter channel
A floodplain is…
a generally flat area of land next to a river or stream
What makes the floodplain wider?
when there is a significant amount of meander migration
What is an estuary
Where the River Meets the Sea
What often forms in estuaries
brackish water
What is a storm hydrograph
a graph on which river discharge (y-axis) is plotted against time (x- axis)
What is river discharge?
the volume of water flowing through a river channel; measured at any given point in cubic metres per second
Give the name for the time between the peak rainfall and peak discharge
Lag time - the time taken between peak rainfall and peak discharge.
If there is a short lag time what does this mean?
water is reaching the river quickly, so there is a greater chance of a flood
If there is a steep rising limb what does this mean?
the more likely a flood is to occur
Identify one physical factor that increases the risk of flooding.
steep slopes
Identify one human factor that increases the risk of flooding.
Constructing buildings and surrounding roads and paths
Identify one physical factor that reduces the risk of flooding.
physical barriers such as levees or seawalls
