Water security

Question 1

Sources of Water

Answer 1

• Water can be extracted from both surface and underground stores by the process of removing the water from the source by ABSTRACTION.
• Surface stores include rivers, lakes, melting glaciers and resevoirs.
• Underground stores are aquifiers, these are areas of porour rock below the Earths surface which are full og small holes and saturated water, it can be pumped out of them via deep boreholes drilling to the rock.

Question 2

Water availability

Answer 2

There is enough fresh water on earth for 7 billion people yet it is distributed unevenly and too much is wated, polluted or unsustainably managed.

Water availability varies globaly, for example in areas such as Brazil and Gabon annual rainfall is very high and Australia is wealthy enought to invest in schemes despite low rainfall.

Water availability is much lower in other areas, for example egypt has a very arid climate and inadequate water treatment facilties.

Question 3

Physical factors that effect the availability of water

Answer 3

Climate
Geology
Drainage

Question 4

Physical factors that effect the availability of water - Climate

Answer 4

• Most places rely on rainfall for their water supply.
• Hot climates means water from water sources is lost through evopration which can cause water scarcity.
• Very high rainfall can overwehm sewers and water treatment plants and can increase runoff into urban areas, this can reduce the quality of the water.

Question 5

Physical factors that effect the availability of water - Geology

Answer 5

• When rain falls on impermeable rock it cant soack in, so it flows into rivers and lakes.
• When rain falls on permeable rocks it flows through them and can form aquifiers, water is much harder to extract from this, although less evaporation occures.
• Some rock contains salt and minerals that dissolve into water, amking them unsuitable for drinking without treatment.

Question 6

Physical factors that effect the availability of water - Drainage

Answer 6

• These systems move water from one area to another, changing the distirbution of water.
• large drainage basins cover more land, so are more likely to recieve a lot of rainfall, increasing water supply.
• In some areas drainage systems dont have enough quality to cope with heavy rainfall, this can cause sewage systems to overflow, affecting water quality.

Question 7

Human factors that affect water availability

Answer 7

• Treatment faciltiies and infastructure to supply safe drinking water.
• Overuse and overexploiation.
• population density

Question 8

Characteristics of areas with water surplus

Answer 8

• Climates giving regular, plentiful rainfall, resulting in good runoff and stores such as aquifiers large vodies of freshwater sources and low evaporation rates.
• Effective water treatment and manegement protects against water pollution and esnures a good water quality and supply.
• Low water usuage characterisitcs, for example low population or efficient usuage of available water

LOCATED in temperate or tropical locations such as south america, europe, north america and asia.

Question 9

Characterisitcs of areas with water scarcity

Answer 9

Both natural and physical made, effects every continent, 1.2 billion people suffer from physical water scarcity.

Arid regions with physical water scarcity, resoruces cannot reach demand of the population.

LOCATION, North africa and middle east

Question 10

Pattern of water demand

Answer 10

North america and australia have the highest per capita water use globaly, very affluent regions that use much water on domestic appliances.

Sub-saharan africa has the lowest per capita usage simply because rainfall is unreliable and they lack infastrutre to supply water effectively.

Question 11

Global demand trends

Answer 11

Global demand is rising for two reasons…

Population growth - More poeple means more water is needed for drinking, washing, preparing food. The growing population also means that demand for food, electricity and other goods increases.

Economic development - As countries develop, energy use increases and manufacturing grows, energy production and manafacutring use alot of water, as peoples wealth increases they become more affluent.

Question 12

Water stress

Answer 12

When demand for water exceeds supply, or when water is not high enough quality to use.

Results of a imbalance between water use and water resources and leads to situations where the lack of water is a mjor constraint on human activity.
How much water is used in proportion to the total resource available.

Deterioation of QUALITY, organic polluton and saltwater into aquifiers

Deterioation in QUANTATY, over abstraction.

Question 13

Components of water demand

Answer 13

• Agriculture 70%
• Industry and commercial use 22%
• Domestic and household use 8%

IN HIGH INCOME COUNTRIES
Agriculture 30%
Industry and commercial use 59%
Domestic use 11%

Question 14

Strategies to increase water supply

Answer 14

Catchment
Diversion and transfer
Storage
Desalination

Question 15

Strategies to increase water supply - Catchment

Answer 15

• This means collecting water for use
• Rainwater harvesting is an example of a water cathcment scheme, instead of allowing the water to fall on the ground and soak into the soil, it is intercepted before it hits the ground and stored in tanks.
• This allows people to quickly access water in areas of shortage, rather than having to exctract it from groundwater or surface storage.

In Bermuda there are no rivers or lakes and groundwater is very hard to access, to avoid water chortages every house is built with a stepped roof that is designed to collect enough rainfall to meet the water needs of the people.

Question 16

Strategies to increase water supply - Storage

Answer 16

• Water can be stored during times of surplus and then use during deficit.
• Creating a resevior through a dam and fill during periods of high rainfall and the water can be used during direr periods, this ensures a consitent flow od water in the river all year round..

FOR EXAMPLE the Avon Dam and Resevoir in Devon was constructed in the 1950s to ensure a regular water supply.

Question 17

Strategies to increase water supply - Desalination

Answer 17

• Desalination is the removal of salt from seawater so it can be used as a water source, seawater can be heated to evaoprate it and then condensed to collect freshwater.
• Seawater is abundant in many areas that lack sufficient freshwater, so desalination can signifcantly increase water security.
• However a lot of energy is required to desalinate water, this means it is a expensive way of increasing water supply, and as most energy comes from fossil fuels, desalination can contribute to fossil fuels and climate change, desalination is also a less viable option in LICs.

Question 18

Strategies to increase water supply - Diversion and treatment

Answer 18

• Water transfer schemes involve moving water from areas of surplus to areas of shortage, this is normally done by pumpting through pipes, tunnels and cannals. N S project china.
• Potentiallu increasing water security at the recieving area, but it can also increase water stress for the area it is diverted from, infastructure is expensive and will carry enviromental impacts.

Question 19

Strategies to manage water consumption

Answer 19

• Reduce demand in domestic and buisness water consumption
• Reduce demand in agriculture

Question 20

Strategies to manage water consumption - Domestic use

Answer 20

• People can take showers instead of baths, water efficient shower heads.
• Displacement bag to toilets reduces water needed to flush and installing a modern water efficient toilet. Around 30% of water in homes is used to flush toilets
  In 2001 the Uk government banned the insatlation of toilets that use more than 6 litres per flush.
• Water efficient dishwashers and washing machines
• Water meter, charge users for the exact amount of wate they use, so encoruages people to use less water, since 1990 every new house built in the UK is fitted with a water meter.

Question 21

Strategies to reduce water consumption - Agriculture

Answer 21

• Farmers can install drip pipes that direct water to exactly where its needed and collect storm water for irrigation.
• Farmers can also change their practises by watering crops early in the morning to reduce water loss through evapotranspiration or by contouring ploughing to reduce runoff.
• Soaker hoses with small openings allow water to seep out, they are placed at the plant base.
• Micro-sprayers are used overhead and deliver a very fine mist that can be controlled.
• Water early morning to avoid evaporation losses.

Question 22

Sustainability issues associated with water management

Answer 22

Sustainability issues associated with water management are concerbed with achieving a long-term balance between supply and demand, this will help maintain water supplies in the future.

This can be achieved through…
Virtual water trade
Conservation
Recycling and ‘greywater’
Groundwater management

Question 23

Sustainability issues associated with water management - Virtual water trade

Answer 23

• Virtual water is the term used to describe water that has been used in the production of something, for example the water required to grow a tonne of lemons or produce a tonne of steel.
• When these products are traded between countries, the virtual water is also traded.
• Sometimes products that require a lot of water to make are exported from countries with high water stress, for example india is the world largest exporter of basmati rice, one of the most water intensive crops in the world.
• Being aware of this can help countries attempt to manage their water more sustainably.
• For example middle easter countries where water is scarce may choose to import foods with a high virtual water value from countries with more water, similiary they should chose not to grow crops with a high vritual water value.

Question 24

Sustainability issues associated with water management - Groundwater management

Answer 24

• Groundwater can be managed to make sure that its quantity and quality are conserved.
  For example the amount being extracted can be monitored to ensure it is not extracted faster than it is naturally replaced. Laws can be passed to prevent over-extraction.
  Farmers can be encouraged to apply less artifical fertilisier and pesticides to farmland and companies that leak or dump tosic waste can be fined.
• In places where groundwater has been overexploited, aquifiers can be artifically recharged, for example INJECTION WELLS allow water to be piped back into depleted aquifiers. INFILTRATION STRUCTURES are water filled basins, ponds or trenches from which water infiltrates to the aquifier.

Question 25

Sustainability issues associated with water management - Recylcing and ‘Greywater’

Answer 25

• Recycling water means treating used water to make it safe to reuse straight away.
• Most recycled water is used for irrigation, industry, power plants and toilet flushing, though it can also be treated enough to make it safe to drink.
• Recycling makes water supplies more sustainable because it helps people meet their water needs without extracting more water from rivers or from groundwater.
• ‘Greywater’ is a type of recycled water its mostly waste water from homes and buisnesses, washing machines and showers etc. This water is relatvively clean and it can be used for water gardens, toielts and irrigation without being treated.
• Using ‘greywater’ can make water supplys more sustainable, it also means that clean water isnt treated unecessastily.