water Flashcards
WHY ARE WE FACING A GLOBAL WATER CRISIS? (4)
Because the demand for water has been doubling every 20 years
Water is being wasted and polluted
Water distribution is uneven, leading to droughts in some areas
Changing diets also increases demand for water because some people richer, and start to buy and eat more meat and dairy which needs to be produced
why is it likely hat the global water crisis will get worse
Due to an increase in population and global warming which leads to changing rainfall patterns and water evaporation, and due to more development, so the industrial sector, the demand for water increases.
what are the main methods of water supply (4)
dams and reservoirs
wells and boreholes
desalination
rainwater harvesting
what is a reservoir
an artificial lake made to store water temporarily.
what is a dam
a barrier that holds water back. Mainly used to save, manage and prevent flow of excess water into specific regions. (affect 60% of the world’s major river basins)
wells and boreholes
A means of tapping into various types of aquifers (water bearing rocks), gaining access to groundwater. They’re sunk into the water table.
A borehole is drilled by machine and has a small diameter, wells are larger in diameter and sunk by hand
what percentage of the world’s water comes from underground sources
70%
what is desalination
Desalination is the process of removing slt and other impurities from seawater to make it drinkable freshwater. (Either by heating and condensing, or filtering it. It needs a lot of energy (unsustainable because fossil fuels are burned in the process).
how many people worldwide rely on desalination
300 million people worldwide rely on it
what is rainwater harvesting
Process of collecting and storing rainwater from rooftops or other surfaces for later use. It’s then filtered and stored.
how many countries worldwide is rainwater harvesting used in
over 100 countries worldwide
WHY HAS GLOBAL DAM CONSTRUCTION DECLINED SINCE PEAK IN 1970s?
because most of the best sites for dams are already in use or such sites are strongly protected by environmental legislation and therefore off-limits for construction.
ADVANTAGES OF USING DAMS AND RESERVOIRS AS WATER SUPPLY METHOD
(5)
Reliable water supply-they store a large amount of water, which ensures a consistent and reliable supply for drinking, irrigation and industrial use. (especially during droughts or dry seasons)
Can also replicate it on smaller scales and is simple and easy extraction process
Flood control
Can be used for HEP
After initial investment, you don’t need to spend anymore money
DISADVANTAGES OF USING DAMS AND RESERVOIRS AS WATER SUPPLY METHOD
(8)
Environmental impact- the building of dams can lead to the flooding of large areas,
disrupting ecosystems,
displacing local communities as it uses up land
Reduced fertility on floodplains as alluvium doesn’t reach them
affecting wildlife habitats.
This can cause long-term environmental changes.
Expensive
Water is likely to be contaminated so needs to be purified and cleaned.
Water will also be warmer as its on surface
well is (deepness, how is it dug, how is water drawn up, and where is it most common)
WELL:
Shallow (20-30 metres)
Dug manually or with basic machinery
Water is drawn up by a bucket or hand pump
More common in agricultural and rural areas
borehole is (deepness, how is it dug, how is water drawn up, and where is it most common)
Deep (reach hundreds of metres)
Drilled using specialised equipments
Usually have mechanical pumps to extract water
Common in areas where groundwater is deep or in urban/industrial areas.
difference between well and borehole
Overall, wells are shallow, manually dug, and more common in agricultural areas while boreholes can reach hundreds of metres, are dug with specialised machinery and more common in industrial areas.
WHAT IS AN AQUIFER :
Underground layer of permeable rock, sand or gravel which allows the flow of groundwater
WHY ARE WELLS AND BOREHOLES GENERALLY THE MOST IMPORTANT WATER SUPPLY METHODS IN ARID AND SEMI-ARID CLIMATES?
because dry areas have limited water on the surface as it evaporates quickly and this is why underground water sources allow water to be available and not get evaporated. Also dry areas usually lack lakes and water sources meaning wells and boreholes allow water to be conserved at a smaller distance for everyday use.
advantages if wells and boreholes
- Reliable water supply (especially in dry regions)
- Easy to construct
- Water is cleaner
- More water than in rivers
- Sustainable as its extracted slowly
DISADVANTAGES OF WELLS AND BOREHOLES
(2)
High cost because of expensive drilling equipment and skilled labour making installation expensive
Unsustainable if rate of extraction is faster than rate of replenishment
advantages of desalination (4)
Provides freshwater
Reliable because ocean won’t run out & doesn’t rely on specific weather conditions
Sustainable (reverse osmosis)
Cheap if its reverse osmosis
disadvantages of desalination (4)
High cost
Disposing of the salty product can harm marine ecosystem if not well managed
Needs a coastline
Need reverse osmosis technology for it to be sustainable and cheaper
WHERE WOULD DESALINATION BE USED
(example country & why)
UAE
lack of freshwater sources, it has limited natural freshwater resources, like rivers or lakes so relies heavily on desalination to meet water demands for drinking and agriculture
high water demand due to population growth + climate. There is rapid urbanisation, growing populations and hot, dry climates so demand for water is very high in that region, making desalination a necessary solution to supplement water supply.
what is a trend
change over time (shown on line graph)
what is a pattern
spatial variations over an area (how something varies from place to place) (shown on maps)
HOW MUCH OF WORLD’S FRESHWATER IS FOUND ON SURFACE?
1.2 % (rivers, lakes…)
HOW MUCH OF WORLD’S WATER IS FRESH
2.5%
where is the worlds fresh water stored and how much in each (4)
70% in the form of ice
28 % groundwater
1.2% is surface water (lakes, rivers…)
Can also be found in the atmosphere
WHAT ARE THE 3 SECTORS OF HUMAN USE OF WATER
domestic (household things like washing machines, showers)
industry (factories)
agriculture (to grow food)
how much human water usage is in domestic
11%
how much human water usage in in industry
19%
how much human water usage is used in agriculture
70%
WHAT’S THE MAIN DIFFERENCE IN HOW MEDCs AND HICs USE THEIR WATER SUPPLY COMPARED TO LICs
HICs use less water for agriculture while HICs have a much more balanced water supply
why do HIC have a much more balanced water usage and lower agricultural usage
ey have natural resources (from rain) and better technology meaning their irrigation methods are more efficient so less waste.
HOW DOES WATER USE IN THE THREE SECTORS CHANGE AS A COUNTRY DEVELOPS
As a country develops, the use of water for agricultural purposes decreases significantly. This is due to reliance on irrigation for farming. As the country develops, the agricultural sector becomes more efficient with improved irrigation techniques,reducing its overall share of water consumption.
while the use of water for industrial purposes increases, and domestic use also does slightly as people have more money and have better technology (domestic appliances like washing machines and showers) so they buy better ones). LICs are not developed and so a lot of people don’t have a water supply like pipes, so need to walk often for hours to a well, where they get their water. So HIC, also invest more on distribution of pipes.
WHAT IS VIRTUAL WATER
Virtual water is the hidden (indirect) water that is used to produce goods and services. (mostly in food and industrial products)
HOW CAN VIRTUAL WATER INCREASE PER CAPITA USE OF FRESHWATER (4)
- importation of goods and products
- agricultural production
- energy and industrial production
- consumption patterns
how does the virtual water use increase with import of goods and products
imported goods contain hidden water (when a country imports food, clothes, or manufactured products, it also imports the water used for their production. Meaning that even if a country doesn’t use a lot of water directly, its virtual water footprint can still be large.
how does the virtual water use increase with agricultural production
foods (meat, rice, wheat) require huge amounts of water to produce. A high consumption of food means higher per capita virtual water use (more demand, more being grown, more water being used).
how does the virtual water use increase with energy and industrial production
the manufacturing of cars or electronic devices (as well as energy production like HEP) consume large amounts of water. If the country is very industrialized, or imports those products, its virtual water use increases.
how does the virtual water use increase with consumption patterns
Wealthier nations with high meat, dairy and processed good consumption have higher virtual water footprints than LICs with less because these products need a lot of water for their production.
overall, how does virtual water increase a country’s per capita use of freshwater
by including all the water used to produce the goods and services people consume, not just the water they use directly.
WATER SHORTAGES ARE A RESULT OF?
Lack of correlation between population density and rainfall total
what is physical water scarcity
PHYSICAL WATER SCARCITY: is when physical access to water is limited (demand for water exceeds amount of water physically available)
what is economic water scarcity
ECONOMIC WATER SCARCITY: exists when a population doesn’t have the necessary monetary means to utilise an adequate source of water. ( lack of investment in water infrastructures)
IMPACTS WATER SCARCITY CAN HAVE ON LOCAL PEOPLE AND THEIR PROSPECTS FOR ECONOMIC DEVELOPMENT (6) + explanation
Reduced agricultural productivity (water is needed to grow plants- irrigation) which means that in areas where farming is a main job source then people will not make as much money from selling due to lower crop yield. Can lead to malnutrition (not enough food)
Health, lack of clean water will mean people will have poor sanitation (water borne diseases) and more money will be spent in hospitals and healthcare. And also, peoples hygiene will decrease due to less showers
Less industrial growth (many industries need water for energy (HEP) so a lack of water reduces productivity and sales, can lead to more environmental issues as you burn more fossil fuels.
Migration as people migrate to places where water is not so scarce- this leads to overpopulation and strain on resources which decreases economic development
Will involve more time and energy collecting water. (women need to go to the water hole or communal well and carry the buckets, which takes time and energy. Also means they spend so much time collecting water, they don’t get education.
Decline economy, decline in fishing and tourism (fish cant survive in low quantities of water meaning the fisherman wont have so much product to sell, tourists won’t be as attracted to a country which doesn’t have main attractions like lakes,rivers etc…)
HUMAN ACTIVITIES WHICH INCREASE WATER SCARCITY (7)
inefficient use of water in irrigation systems
over extraction of water
deforestation
pollution of water sources
population growth + urbanization
construction of dams
industrial use of water
how does over extraction of water increase water scarcity
excessive withdrawal from aquifers, agriculture, industry and domestic use leads to depletion and drying up of wells
how does deforestation increase water scarcity
cutting down trees reduces rainfall infiltration, which leads to less groundwater storage and more increased surface runoff, reducing water availability. ( it goes into the sea, and doesn’t recharge the aquifers)
how does pollution of water sources increase water scarcity
Industrial waste, agricultural chemicals and domestic sewage can contaminate freshwater supplies, making them unsafe for use.
how does population growth + urbanization increase water scarcity
expanding cities increase demand for water, and impermeable surfaces reduce groundwater storage
how does climate change increase water scarcity
human induced climate change means that there can be altered rainfall patterns, prolonged droughts, and desertification
how does the construction of dams increase water scarcity
dams store water but they can disrupt downstream water supply, leading to shortages in other areas
how does industrial use of water increase water scarcity
large scale industries consume large amounts of water, especially in sectors like mining, textiles and power generation. Leading to waterborne diseases
WHAT NEEDS TO BE DONE TO REDUCE WATER SCARCITY (4)
invest in infrastructure (wells) (to hold water avoids droughts evaporating water) and desalination (convert sea water to freshwater.
public awareness (educate communities about water conservation methods, promote water recycling)
enforce policies (to protect natural water sources- avoid pollution) (sustainable farming practices, methods like drip irrigation which will minimize water usage in agriculture)
replacement of damaged pipes
how much percentage of the world’s surface does water cover
71%
how many billion cubic kilometres of water on earth
1.4
what percentage of water on earth is poisonous to us
96.5%
how many thirds of freshwater available to us is locked in ice caps and glaciers
2 thirds
is water distributed evenly
no
