Water Flashcards
(40 cards)
What are the major features of a famine drought?
(Food deficit)
- Loss of natural vegetation
- Increased risk of wild fires
- Wind-blown soil erosion
- Desertification
What are the main features of a hydrological drought?
(Stream flow deficit)
- Reduced infiltration
- Low soil moisture
- Little percolation and groundwater recharge
What are the major features of a meteorological drought?
(Rainfall deficit)
- Low precipitation
- High temperatures
- Strong winds
- Increased solar radiation
- Reduced snow cover
What are the major features of an agricultural drought?
(Soil moisture deficit)
- Low evapotranspiration
- Plant water stress
- Reduced biomass
- Fall in groundwater levels
What are the impacts of a meteorological drought?
- Loss of soil moisture
- Supply of irrigation water declines
What are the impacts of hydrological droughts?
- Reduced water storage in lakes and reservoirs
- Less water for urban supply and power generation - restrictions
- Poorer water quality
- Threats to wetlands and wildlife habitats
What are the impacts of agricultural droughts?
- Poor yields from rain-fed crops
- Irrigation systems start to fail
- Pasture and livestock productivity declines
- Rural industries affected
- Some government aid required
What are the impacts of a famine drought?
- Widespread failure of agricultural systems
- Food shortages on seasonal scale
- Rural economy collapses
- Rural-urban migration
- Increased malnutrition and related mortality
- Humanitarian crisis
- International aid required
Order of drought duration and severity? (From shortest to longest)
- Meteorological
- Hydrological
- Agricultural
- Famine
What is the PDSI?
Palmer Drought Severity Index- Focuses on monitoring the duration and intensity of large-scale, long-term, drought-inducing atmospheric circulation.
What happens in a normal (non- El Niño) year?
- The trade winds blow westwards (from South-America to Australia) across the tropical Pacific
- The winds blow towards the warm water of the western Pacific
- Convectional uplift occurs as the water heats the atmosphere
- The trade winds push warm air westwards. Along the east coast of Peru, the shallow position of the thermocline allows winds to pull up water from below
- This causes upwelling of nutrient-rich cold water, leading to optimum fishing conditions
What is water scarcity?
Less than 1000m of water available per person per year.
What is physical scarcity?
There is not enough water to meet the demand.
What is economic scarcity?
Water is available but people cannot afford it.
What is water stress?
Less than 1700m3 of water available per person per year.
What is water insecurity?
Present and future water supplies cannot be guaranteed.
What are the 4 main reasons for increased global water scarcity?
Increasing population and urbanisation
Improved living standards
Industrialisation
Agriculture
How does increased population and urbanisation affect water?
- Demand for water is growing twice as fast as the population
- Half the world’s population live in urban areas. By 2030, the urban population in Africa and Asia is expected to double.
How does improve living standards change affect water scarcity?
- Rising incomes in developing and emerging economies
- Increased meat consumption
- Larger homes
- Production of more cars, appliances and gadgets
How does industrialisation affect water scarcity?
- Industrial consumption will increase by 400% by 2050
- Increased industrial pollution contaminates supplies
How does agriculture affect water scarcity?
- Largest consumer of water
- By 2050, 60% more food will be required
- Depleting aquifer levels and contamination by salt water
What are desalination plants?
Remove salt from water in order to obtain freshwater supply
What are the pros of desalination?
- Sustainable due to vast amounts of seawater supply
- Advancing technology makes the process less energy-intensive
What are the cons of desalination?
- Major ecological impact on marine life as left over water returned from desalination plant has double the salt concentration of sea water which can impact coral and food webs.
- Energy intensive process