Hydrographs and Flooding (AQA GCSE Geography): Flashcards
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Practise the cards
15 cards from this deck
What is river discharge?
What is river discharge?
Volume of water flowing in a river per second
River discharge units
River discharge units
Cubic metres per second
Hydrograph definition
Hydrograph definition
Shows discharge at a point in a river over time in relation to rainfall
Peak discharge definition
Peak discharge definition
Maximum amount of water held in the channel
Peak rainfall definition
Peak rainfall definition
Maximum amount of rainfall (millimetres)
Lag time definition
Lag time definition
Time between peak rainfall and peak discharge
Rising limb
Rising limb
Shows the increase in discharge
Falling limb
Falling limb
Shows return of discharge to normal/base flow
Base flow definition
Base flow definition
Normal discharge of the river
No vegetation effect on lag time
No vegetation effect on lag time
Short lag time - water runs off into river quicker
Vegetation effect on lag time
Vegetation effect on lag time
Longer lag time - plants intercept rainfall
Short lag time consequence
Short lag time consequence
Increases flood risk
Rainfall effect on flood risk
Rainfall effect on flood risk
Saturated soil can't infiltrate, increases runoff
Deforestation effect on flooding
Deforestation effect on flooding
Increases flood risk
Impermeable surfaces & flood risk
Impermeable surfaces & flood risk
Impermeable materials (concrete) increase runoff