Geography year 10 mocks revision Flashcards
Drainage basin
an area of land drained by a river and its tributaries
confluence
where a tributary joins a larger river
watershed
the edge of a river basin
4 erosional processes
hydraulic action=force of water
solution=chemical in water dissolve the bed and banks
abrasion=rivers bed and banks eroded from its load
attrition=rivers load erodes each other so turns into smaller particles
4 transportation processes
traction=load rolled along river bed
saltation=smaller pebbles bounced along river bed
suspention=fine particles carried along within the water
solution=minerals dissolved in water
interlocking spurs
projections of high land both sides of a v-shape valley
how are waterfalls made?
where there is a section of hard rock upstream and soft rock downstream. water erodes the soft rock where it meets the hard rock and forms a vertical drop
how are gorges formed?
plunge pool forms under the waterfall and is undercutting happens. when the overhang can’t hold the weight of the water it collapses reading the waterfall upstream. happens many times forming a gorge
oxbow lakes
meander loops become very large and the gap between the loop gets eroded away. This creates a shortcut and a straight channel. over time the old meander gets detached and becomes an oxbow lake
levees
when the river floods its banks, sediments builds up on the rivers banks, after many floods the sediment builds up and make the river bank taller on both sides.
human causes of flooding
building impermeable surfaces like roads where water sits on top off. hedges have been destroyed means less interception of rainwater
examples of hard engineering to stop rivers flooding
dams/reservoirs
channel straightening
river relief channel
examples of soft engineering to help stop river flooding
flood warning
preparation
floodplain zoning
what waves erode beaches
destructive waves because they have a strong backwash
what direction does longshore drift happen?
the direction of the prevailing wind
