Floodplains, Levees, Estruaries Flashcards
What are the characteristics of a levee and what is it?
Raised river banks , composed of gravel, stone, steep sided, fairly flat top
Naturally raised river banks either side of a river thats prone to flooding
How are levees formed?
When a river burst its banks, friction with the land reduces velocity and causes deposition and heavy sediment and with each flood the banks are built up higher
What is a flood plain?
Large are of flat land either side of a river prone to flooding
How are floodplains formed?
The width of a flood plain is due to meander migration where the outside bends erode laterally into the edges of the valley, which eventually move downstream and cuts a wider valley. When flood plains have receded the flood plain is more fertile and higher due to the deposits of silt and alluvium and build up over hundreds of years
What is an estuary?
Tidal part of river where fresh and salt water merge, high tidal range, mudflats, tidal bores
How are estuaries formed?
Valleys become flooded, as well as, salinity increases towards the sea, there are two sources of sediment and the estuary is tidal (both fluvial and marine processes)
