Water EQ2 Flashcards
1
Q
What are the 4 types of drought?
A
- Meteorological- shortfall or deficiency of water over an extended period
- Hydrological- reduced streamflow, lowered groundwater levels, reduced water stores
- Agricultural- famine, and starvation
- Socioeconomic
2
Q
What are the causes of meteorological drought?
A
- Research suggests sea surface temperature important factor in short-term precipitation deficits
- Physical causes on partially understood -complex interactions between different spheres
3
Q
How does El nino work?
A
- Strong trade winds push warm ocean currents to the east around South America, and leaving cooler ocean currents around Australia
- Occur every 3-7 years and usually last for 18 months
4
Q
How does la Nina work?
A
- Involve build-up of cool water around South America due to no trade winds- lead to severe drought conditions in parts of SA- Very warm water moving east- west
- Sometimes happens after EL nino
5
Q
What are the causes of desertification and where does it take place?
A
- Changing rainfall patterns
- Vegetation cover becomes stressed and begins to die leaving bare soil
- Bare soil eroded by wind and occasional intense shower
- When rain does fall only for short, intense periods- difficult for soil to capture and store it
- Usually takes place in semi- arid land on edges of existing deserts
6
Q
What human actions exacerbate desertification?
A
- Over-abstraction of surface water and groundwater
- Population growth- pressure on land to grow more food
- Overgrazing- destroy vegetation cover
- Overcultivation- exhausts the soil
- Deforestation- roots no longer bind soil and erosion occurs
7
Q
What human actions exacerbate desertification?
A
- Over-abstraction of surface water and groundwater
- Population growth- pressure on land to grow more food
- Overgrazing- destroy vegetation cover
- Overcultivation- exhausts the soil
- Deforestation- roots no longer bind soil and erosion occurs
8
Q
What is the situation with drought in Australia?
A
- It is a recurrent annual feature- up to 30% of the country is affected ( El Nino links)
- Careful management of scarce water resources- large scale recycling of greywater, desalination plants, and water conservation strategies
9
Q
Why are wetlands useful?
A
- Act as temporary water stores
- Recharge aquifers
- Trap pollutants
10
Q
How does drought impact wetlands?
A
- Less precipitation- less interception- less infiltration and percolation - water tables fall- increase evaporation and decreased transpiration
11
Q
How does drought affect forests?
A
- Increase sisceptibility of pines and firs to fungal disease
- Tree mortality increase
- less interception- reduced infiltration and overland flow
- Deforestation also has massive effects
12
Q
What are meterological casues of flood?
A
- Intense storms- lead to flash flooding- common in mountainous areas
- Prolonged, heavy rain- asian monsoon
- Rapid snow melt- siberia in warm spring
13
Q
What physical circumstances increase liklehood of flooding?
A
- low-lying areas with impermeable surfaces
- impermeable rocks on ground surface
- ice dams suddenly melt- glacial lakes released
- volcanic activitygenerates meltwater suddenly released- jökulhlaups
- earthquakes cause failure of dams or lanslides- bloking rivers
14
Q
What are some different human actions that exacerbate flood risk?
A
- Impermeable areas of tarmac
- Dams built to supply towns with water
- Ploughing compacts soil
- Deforestation stops woodlands from intercepting and transpiring
- pasteurised land does not allow water to sink in
- wells sunk to supply settlements.
15
Q
What are a few examples of river mismanagement of rivers using hard engineering?
A
- Channelization- improves river discharge and reduces flood risk, but it simply displaces the river downstream
- Dams- block flow of sediment down a river, so reservoir gradually fills up with silt- increases riverbed erosion downstream
- River embankments- designed to protect from floods, but they can fail when a flood exceeds there capacity- this makes the scale of flooding much greater.
16
Q
What is more preferred in managing rivers in flooding soft or hard engineering and why?
A
- Soft-engineering like making use of the floodplains as nature intended as temporary stores of water. This is preferred because of the mismanagement that can happen with hard-engineering leading to a greater impact?
17
Q
What are a few socio-economic impacts of flooding?
A
- Death and injury
- Spread of water borne diseases
- Damage to property
- Interruption of water and energy supplies
- Destruction of crops and loss of supplies
18
Q
What are some environmental impacts of flooding?
A
- recharged groundwater stores
- increased connectivity, between aquatic habitats
- soil replenishment
- triggers breeding, migration and dispersal
- pollutants can be brought into
- soil and river channel erosion
- soils may become waterlogged
19
Q
What were a few impacts of the UK flood events 2015-2016?
A
- 16000 properties in England flooded
- total economic costs £5 billion
- Roads and railways blocked
- Businesses damaged
20
Q
What was to blame for the lack of flood protection?
A
- Budget cuts in the amount of money being spent on flood defenses
- Global warming
- Poor land management
- EU puts environmental conservation ahead of regular dredging of rivers.
21
Q
How has climate change affected precipitation?
A
- Higher humidity in the atmosphere creates a greater potential for condensation and precipitation , but patterns are variable
- Rainfall is likely to be heavier and more intense
22
Q
How has climate change affected evaporation/evapotranspiration?
A
- Increased a lot especially over oceans, but also over land
- Increasing the amount of moisture in the atmosphere
23
Q
How has climate change affected runoff and streamflow?
A
- Precipitation is in heavy short bursts due to higher humidity levels, or where snow and ice are melting , more water will runoff the surface and enter streams, increasing flood risk
24
Q
How does climate change affect snow?
A
- Amount of snow collecting and surviving from one winter to the next is decreasing as air temperature increase.
- Snow depths has been decreasing and early melting has been observed
25
How has climate change affected glacier mass?
- Most glaciers in the world in retreat due to warmer temperatures, especially at lower altitudes
- Glaciers in Antarctica are thinning as ice shelves on the warmer sea, allowing glaciers to move faster
26
How does climate change affect lakes and reservoirs?
- Higher evaporation rates from open water sources due to warmer air temperatures have decreased water heights, and lower precipitation means that they are not refilled in times of drought.
27
How does climate change affect lakes and reservoirs?
- Higher evaporation rates from open water sources due to warmer air temperatures have decreased water heights, and lower precipitation means that they are not refilled in times of drought.
28
How does climate change affect permafrost?
- Tundra areas are experiencing the greatest degree of warming, therefore all forms of permafrost are experiencing melting- this changes the surface and soils of these areas
29
How does climate change affect permafrost?
- Tundra areas are experiencing the greatest degree of warming, therefore all forms of permafrost are experiencing melting- this changes the surface and soils of these areas
30
How does climate change affect soil moisture?
- Big contrast around the world- some moisture levels have increased, others have decreased, but higher air temperatures have drawn more water from soils by evaporation.
31
What factors
