Zusammenfassung der Ressource
River Flooding - Causes
- Prolonged rainfall
- Long period of rain
- soil become
saturated
- Further rainfall can't
infiltrate - increases
run-off into rivers
- Increases discharge
- Heavy rainfall
- A lot of runoff -
increases
discharge quickly
- Snowmelt
- A lot of snow or
ice melts into river
in short space of
time
- Increases discharge quickly
- Relief
- If steep sided
valley - water will
reach river
channel much
quicker
- Increases discharge quickly
- Geology
- If river in area of impermeable rock,
more water flowing on surface
- More runoff - risk of
flooding higher
- Deforestation
- Trees take in water (leaves, roots)
- Cutting down trees
increases volume of
water that goes to river
- Increases discharge
- Causes soil errosion
- So soil washed away
- raises river bed
- Reduces volume of
water river can hold
- Urbanisation
- Buildings with impermeable surfaces
(roads, concrete)
- Increases surface runoff
- Increases
discharge quickly