5.7 - Physical And Human Causes Of Water Insecurity

Question 1

Water stress

Answer 1

Annual water supplies per person fall below 1700m^3

Question 2

Water scarcity

Answer 2

Annual water supplies per person fall below 1000m^3.

Question 3

Physical Scarcity

Answer 3

Occurs when over 75% of a country’s rover flows are being used.
Currently affects 25% of people.

Eg:
North Africa - Nile Delta, Egypt
Northern China - Beijing
N and S India

Question 4

Economic Scarcity

Answer 4

When the development of blue water flow sources are limited by human and financial capacities and technology.
Affects 1bn people.

Eg:
Much of Sub-Saharan Africa
Making Delta Region SE Asia

Question 5

Uneven distribution of water

Answer 5

Water is a finite resource. Only 3% globally is freshwater.

Key physical challenge - 60% of water supply contained in 10 countries.

66% of the population live in areas relieving 1/4 of rainfall.

Question 6

The water development gap

Answer 6

1.8bn people globally don’t have access to clean, potable water.

Un states our basic needs can be met by 1000m^3 pp annually.

Currently, 1/3 of the population is considered short of water.

Question 7

Water and Development

Answer 7

Water is considered ‘lubricant for development’.

Economic growth in all sectors increases demand for water, including the growth of the fracking industry.

Rising demand is often driven by rising living standards > including changing diets and more meat consumption.

Question 8

Climate - Physical Causes of Water Insecurity

Answer 8

The distribution of water globally is related to earths climatic zones. Precipitation and evaposyranspiration rates vary according to latitude.

Equatorial > high conventional rainfall in Tropical Areas

Inter-Tropical Zone > very dry > ie Sahara Desert

Mid Latitude > Temperate regions mixed > ie UK quite humid

Polar regions > semi/arid

Influence of wind patterns and proximity to ocean, seasonality (i.e., monsoons in S Asia), glacial fed streams in spring (i.e., Himalayas)

Question 9

River Systems - Physical Causes of Water Insecurity

Answer 9

Worlds rivers store large amounts of water and transport across continents,
get bigger downstream from tributaries (high temperatures can lead to considerable water loss by evap.)

Seasonal changes can vary discharge and produce distinctive river regimes

Flow can be influenced by many factors ie. Type of precipitation, previous antecedent rainfall, land use/shape/geology/basin size/relief/ human activity.

Question 10

Geology - Physical Causes of Water Insecurity

Answer 10

Permeability and porosity of rock is vital, i.e., Sandstone/Chalk > water permeates into underground drainage systems> Ogallala Aquifer, USA

Impermeable surfaces (Granite) > water remains on surface (instead of permeating into ground seater table) > leads to high surface drainage density > water often stored in surface stores eg. Granite is the dominant rock type in Scotland.

Question 11

Saltwater Intrusion - Human Causes of Water Insecurity

Answer 11

Movement of saline (ocean) water into freshwater coastal aquifers, which can contaminate fresh drinking water sources. Human activities such as overabstraction have increased this.
Ie Califonia

Question 12

Pollution - Human Causes of Water Insecurity

Answer 12

Pollution of groundwater is much less obvious than surface stores, but no less problem.

Industrial waste - 400bn tonnes generated annually, allot is pumped into rivers/oceans ie Ganges, India

Sewage disposal - in developing countries, diseases ie hepatitis/cholera/typhoid common in areas with polluted water.

In China, 300m people drink contaminated water daily, 190m suffer water related diseases annually.

Question 13

Chemical Feltilisers - Human Causes of Water Insecurity

Answer 13

Used by farmers, contaminate ground and surface stores.

Sewage and fertilisers add nutorens to water and increase already growth > eutrophication > dead zones > algal blooms > plant and animal life is impossible.

Question 14

Groundwater Pollution - Human Causes of Water Insecurity

Answer 14

When pollutants are released to ground they make their way into groundwater.

Major sources are industrial and household chemicals, garbage landfills, oil field brine pits, sewage sludge.

Major problem in developing and NEEs eg NE China, linked to ‘Arsencosis’ in Bangladesh, nearly 20% of all wells unsafe because of arsenic in groundwater rock formations.

Question 15

Mega Dams - Human Causes of Water Insecurity

Answer 15

Increase supply of freshwater in some areas, interfere with the flow in other areas downstream.

Also trap sediment in reservoirs, reduces floodplain fertility and flow of nutrients to sea.

Question 16

Overabstraction of Surface and Groundwater Stores - Human Causes of Water Insecurity

Answer 16

Removing water from rivers/ groundwater sources for drinking or irrigation can have unintended consequences.

Worldwide, where is being abstracted from aquifers faster than it can recharge (especially in arid areas), can upset natural saline and freshwater balance too.

Question 17

Future Uncertanties about Water Stress

Answer 17

Population is growing > particularly in areas where water stress is highest. Anticipated global population could grow by 2 - 10 bn by 2030.

Question 18

Agriculture - Key Demand for Water

Answer 18

Is the major global user of water, especially as there’s a struggle to grow food for the growing population.

Some forms of agriculture are more water efficient than 4 of Beef is 10× more ‘Water-Costly’ than producing 1kg of rice.

Water storage and irrigation systems do make agriculture more productive, can be wasteful of water.

Poor management > evaporation, seepage, salinisation, fertiliser pollution.

Question 19

Industry - Key Demand for Water

Answer 19

21% of water used is for industry, predicted rapid rise witharge scale industrialisation of India and China and pop. Growth

The energy sector uses huge amounts, still generally more efficient than agriculture, accept paper manufacturing

Industry has a larger impact on quality of water as opposed to quantity.

Question 20

Domestic (Homes and Municipal) - Key Demand for Water

Answer 20

Only 10% of water usage, smallest category.
This includes gardens, parks, pools, golf courses.

Amount used varies country to country and quality of water also varies.

Global domestic demand seems to double every 20 years > primarily driven by developing world.

Question 21

Virtual Water - Key Concept

Answer 21

Virtual water trade refers to the hidden flow of water if food or commodities are traded from one place to another.

Aka. Embedded water, since its embedded in all the farm products, food and manufactured goods imported.

120l for 1 glass of wine