Water EQ3 Flashcards
What has caused global water stress and waster scarcity?
The combination of rising demands and the diminishing availability of finite supplies as well as the physical distribution have created mass resource shortages
2015, 15% of the worlds population didn’t not have access to safe portable water.
How does the physical distribution of water led to water scarcity?
There is a mismatch between where water supplies are and where the demand is. Water supplies are spread unevenly across the world, 60% of the worlds supplies are contained in just 10 countries.
Why is there a rising demands?
There is a growing gab between demand and supply’s this is because
- rising standard of living (growing consumer society (Asia) higher consumption of water for agriculture and meat)
- economic growth (industry services and fracking)
- irrigated farming (Aral sea, 99% of extraction used for irrigation)
- population growth
What is the definition of ‘virtual water’?
The hidden flow of water when food or other commodities are traded.
What is the definition of water scarcity?
When there is below 1000m3 per person.
What is the definition of water stress?
When there is below 1,700m3 per person
What is the water availability gap?
The water availability gab is the gap between the ‘have nots’ largely in developing nations and the ‘haves’ largely in developed nations due to the imbalance of usages.
What is the definition of physical water scarcity?
When more than 75% of a country’s or regions blue water flows are being used. This currently applies to 25% of the world population e.g. Saudi Arabia who are one relying on desalination plants.
What is the definition of economic scarcity?
When water scarcity is due to the in ability of a country to access it due to lack of technology, capital and good governance. (Sub-Saharan Africa)
What are the physical causes of water insecurity?
- climate variability
- topography and distance from the sea
- geology
- salt water encroachment at the coast
How does climate variability cause water insecurity?
Climate determines the global distribution of water supply by controlling the annual and seasonal distribution of precipitation. Precipitation varies globally as a result of the of atmospheric pressures. This variability makes water source unreliable and maybe unavailable.
ENSO checks and climate change are exacerbating water security.
How does topography and distance from the sea impact water availability?
- Areas with high relief tend to have increased precipitation and surface runoff and may have greater opportunities for water storage (natural lakes).
- Snowfall and glaciers feed many water sources. (Climate change threatening these sources)
How does geology affect water insecurity?
Geology controls the distribution of aquifers that provide groundwater storage. Permeable chalk and sandstone can store vast amounts of water underground which is not subject to evaporation rates and can be accessed through wells.
What are the human causes of water insecurity?
- over extraction of water from rivers, lakes and aquifers
- water contamination from agriculture and industrial waste pollution.
How is over extraction form water sources lead to water insecurity?
Over extraction of water to meet growing demands (population growth, consumer societies) has resulted in diminishing supplies and salt water encroachment.
Salt water encroachment happens as removal of water can upset the natural balance of saline and fresh water causing salt water to encroach inland contaminating supplies.
How is contamination of water supply leading to water insecurity?
Human actions are polluting both surface water and ground water supplies diminishing supplies and creating water insecurity. They are polluted in the following ways
- untreated sewage disposal (water borne disease)
- chemical fertilisers (eutrophication)
- industrial waste
e.g. In Guandong China 80% of recent deaths where the cause of liver and digestive cancer caused by mis disposal of heavy metal toxins for the he Dabaoshan min PE being washed into the Hendshi River.
What is the green revolution?
The use of high yield varieties of crops along with the use of agrochemicals and irrigation to increase yields and improve food supply’s.
Why is the demand for water rising?
- population growth (more people mean higher demands)
- economic development (increases the demand for water for developments in industry, agriculture, services and energy)
- rising living standards (increase in a consumer society ha increased demand per person more washing machines and meat consumption ect)
What are the three main pressure increasing the risk of water insecurity?
- Diminishing supplies
- climate change
- contamination
- impacts of competitive users - Rising demands
- pop growth
- rising demands - Competing demands from users within a basin
- international issues
- upstream bs downstream
- HEP vs irrigation
What is the distribution of physical scarcity?
The distribution of physical scarcity is largely determined by climate (balance between precipitation and evapotranspiration). However factors such as continentality (interior Asia) and topography and significant regionally. As well as geology and climate changes.
What is the distribution of economic scarcity?
This is associated with developing countries that lack capital, technology and governance meaning they can exploit there blue water supply’s. (Sub-Saharan Africa and Haiti)
Why does the price of water vary globally?
The price of water is determined by
- cost of obtaining water (LA has high water costs as it is piped all the way from Colorado)
- degree of demand (in drought conditions water price increases significantly)
- insufficient infrastructure (need to pay for bottled water or form informal vendors normally 2x the price than form a tap)
- who supplies water (private water companies and if the waters clean)
Why is water supply essential for economic growth?
Water plays an essential role is all economic productivity for
- agriculture
- industry
- energy supply
What is the need for water in agriculture development?
Agricultural practises dominate water use about 3,770 kilometres more than twice the total withdrawn for industrial and domestic usage. The green revelation has encouraged the use of high yielding food varieties and the use of irrigation rather then rain fed agriculture massively increasing food availability which is vital for development but this has massive environmental downsides and diminishes water supplies.
How has the Aral Sea been depleted?
The Aral Sea is the 4th largest inland sea which has been steadily shrinking since the 1960 to provide irrigation water for agriculture.
- the sea has declined to 10% of its original size and split into separate lakes
- levels have fallen to 40m
How has water form the Aral Sea benefited development for countries?
- irrigation schemes allowed Uzbekistan (once an incredibly poor country) to become one of the worlds largest cotton exporters.
- irrigation to develop fruit and cotton in a once unproductive region has created jobs for millions of farm workers
C > water extraction has brought the water table to the surface making drinking water and food crops salty and polluted
How does water provide development in terms of industry and energy?
Over 20% of freshwater usages worldwide are for industrial and energy production. Water is essential is essential in the development and production of products (electronics, paper and petroleum) making it important for economic growth. However water pollution is associated with this rapid industrialisation.
C > over half the waste used is either for generating HEP energy or as a cooling mechanism meaning it can be returns virtually unchanged.
What human wellbeing factors does water insecurity impact?
It is important for
- sanitation
- health
- food preparation
2.5 billion people have no access to improved sanitation facilities.