Human activity and drought Flashcards
Rio drought 2014/15:
- Worst drought in (1) years
- Driest region had less than (2)mm of rainfall than usual
- (3) system over Brazil but heavy rainfall in (4)
- Water rationing affected (5) people and got cut in some areas for (6) days
1 - 80 2 - 100 3 - high pressure 4 - Paraguay and Bolivia 5 - 4 million 6 - 3
Rio drought 2014/15
- Power cut due to halted (1)
- (2) of the largest reservoirs dangerously low, some down to (3)%
- Reduced crops of (4) increased global prices over 50%
1 - HEP
2 - 17
3 - 1
4 - Arabica beans
Tipping point:
- Rainforests recycle (1)% of their rainfall
- (2) feedback loop from deforestation and (3) so there is less capacity to regenerate and therefore less (4) and storage
1 - 50
2 - Positive
3 - less precipitation
4 - resilient
Tipping point:
- Global climate change so the (1) cycle and deforestation makes (2) more frequent
- Less absorption of (3)
- Change in regional (4) and an increase in (5) temperature
1 - ENSO 2 - extreme weather 3 - carbon 4 - water cycles 5 - soil
Tipping point:
- Biome change to (1)
- More (2) and so more carbon
- Less dependence on HEP which provides (3) of energy
- Loss of (4) as rainforest
1 - Savannah
2 - wildfires
3 - 70%
4 - carbon sink
Define ‘positive feedback’
A cyclical sequence of events hat amplifies or increases change
Define ‘negative feedback’
A cyclical sequence of events that neutralises the effects of a system
Rio drought not just (1) also contributed by (2) of surface water and ground water (3). Sao Paulo heavily industrialised and shanty towns so (4) is sole supply Government charge (5) to drill a well (6)% of new wells are illegal as they are not registered and so not checked for safety
1 - meteorological 2 - over extraction 3 - aquifers 4 - groundwater 5 - $3,000 6 - 70
Drought in the rainforest:
- (1) billion trees absorbs up to (2) billion tonnes of water vapour daily
- River carries (3) million tonnes back to the Atlantic a day
1 - 400
2 - 20
3 - 17
Drought in the rainforest:
- Younger trees die reducing (1) cover
- Less humidity and (2) so less rainfall
- More tropical sunlight increases (3) vegetation and (4)
1 - canopy
2 - vapour
3 - dying
4 - wildfires
Define ‘drought’
A period of time when weather is abnormally dry which causes a serious hydrological imbalance in a specific region
Why is drought a ‘creeping hazard’?
Typically long onset and so difficult to determine a start date
Areas severely affected by drought has increased to (1) of global land in the past 30 years
30%
What is the cause of meteorological drought?
Rainfall deficit
What are the main features of a meteorological drought?
- Lack of rainfall
- Lack of snow cover
- Strong winds
- High temperatures and solar radiation
