Causes and Characteristics of Flooding (Grade 10 NSC Matric Geography): Flashcards
📚Flashcards
Practise the cards
10 cards from this deck
ShowHide
Practise the cards
10 cards from this deck
Flood definition
Flood definition
Water covering normally dry land
Physical causes (geography)
Physical causes (geography)
Natural factors linked to Earth's structure & processes
Physical cause: heavy rainfall
Physical cause: heavy rainfall
Ground can't absorb all water; rivers burst banks
Physical cause: steep slopes
Physical cause: steep slopes
Water flows rapidly downhill causing flash floods
Physical cause: saturated soil
Physical cause: saturated soil
Can't absorb more water; rainfall becomes run-off
Human cause: urban areas
Human cause: urban areas
Impermeable surfaces cause rapid water run-off
Human cause: deforestation
Human cause: deforestation
Less water absorption; more flows directly to rivers
Discharge
Discharge
Volume of water passing a point per second in a river
Hydrograph
Hydrograph
Graph showing river discharge changes over time
Lag time
Lag time
Delay between peak rainfall and peak discharge