Water Cycle EQ2 Flashcards
What is a drought?
Deficit of water compared to normal precipitation levels
What are the droughts in order of severity and duration?
Meteological
Hydrological
Agricultural
Famine
What is meteological drought?
Shortfalls in precipitation as a result of short term variability within the long term average overall
What is hydrological drought?
Reduced steam flow and groundwater levels from reduced precipitation and high rates of evaporation
What is agricultural drought?
Rainfall deficiency from meteorological drought lead to deficiency of soil moisture
What is famine drought?
Humanitarian crisis leading to food shortages and famines with severe social economic and environmental impacts
What are the physical causes of drought?
Lack of rainfall
Seasons
Heatwaves
Late monsoon seasons
El Niño/ La Niña
What are the human causes of drought?
Over extraction
Over population
Lack of needed infrastructure
Building dams on rivers
Pollution
Deforestation
Climate change
What are the ENSO cycles?
Good example of a longer term physical cause of drought in some regions
What is El Niño?
Climate cycle operating every 2-7 years leading drought in different parts of the world origins
Changes to sea surface temps in southern Pacific Ocean
What is La Niña?
Opposite to El Nino
Clear air sinks at South America warm air rises at Australia
What is the ITCZ?
Intertropical Convergent Zone
Area of low pressure in tropics forms due to action of Hadley cells where north east and south east trade winds meet
What is a blocking high pressure system?
Area of warm weather that block more unstable weather/air moving in
Can remain stationary for weeks/months
What is a monsoon?
Particular wet season lasting several months and happens in a number of regions around the planet
What are human factors that lead to drought?
Building dams- lessens water access below
Water transport schemes- less water for are coming from
Deforestation- water doesn’t stay in the area
Overgrazing
The impact of drought on Brazil and the Amazon rainforest?
Water rationing for 4 mill people
Increased over extraction of groundwater
The impact of drought on Brazil and the Amazon rainforest?
Water rationing for 4 mill people
Increased over extraction of groundwater
$3000 to gain listence to drill a well for groundwater
Aquifers dropped to alarming levels
Wells were shallow and vulnerable to pollution
What is the impact of droughts on an ecosystem?
Foliage loss
Impared growth
Increased susceptibility to pests and diseases
Faulty crops
Decline in pollinating insects
What impacts does drought have on wetland ecosystem?
Leads to severe cracking and compaction
Loss of organic matter
Major impacts during drought
Major impacts on water quality
Why do some areas experience surpluses in water?
Monsoon summer- India
Colder oceans
Why do places experience flooding?
Human reasons
Urbanisation
Agriculture
Deforestation
Mismanagement
Changing land use
Why do places experience flooding?
Physical reasons
Infiltration maximum reached
Drainage basin shape
Snow/melt
Relief
Intense storms
ENSO cycles
Consecutive rainfall events
Impermeable soils
What was the meteorological cause of flooding in Northern England December flood?
The jet stream stayed over north west longer then usual bringing in rain
How much rain fell in Cumbria flood?
341.5mm honister pass
405mm in thrilmere
What increased the flood risk in Cumbria?
Changing of land use by gamers less vegetation due to more fields for sheep
Flood impacts weren’t repaired from the flood in 2009
What is likely to happen by 2100 in the UK
Winter floods are 4.5 times more likely
Summer droughts are 3 times more likely
