Water Lesson 11: Water Insecurity Flashcards
% of people in 2015 without reliable access to safe water?
15%
% of people without clean sanitation in 2015?
25%
% of water as freshwater accessible to humans?
2.5%
% of water available as accessible surface water?
1%
% of accessible fresh water being used in 2010?
60%
% of freshwater untapped?
40%
Why is there huge water insecurity?
Unequal water world
Dwindling supply due to rising demands from a growing global population
% of world population receiving only 25% of the world’s annual rainfall?
66%
Define water stress
Water availability is between 1000-1,700m3 per person
Define water scarcity
Water availability is between 500 - 1000m3 per person
Define water security
The capacity of a population to safeguard sustainable access to adequate quantities of acceptable drinking water for sustaining livelihoods, human wellbeing and socio-economic development, for ensuring protection against water borne pollution and water-related disasters, and for preserving ecosystems in a climate of peace and political stability
How does climate determine water supply?
-Means of annual and seasonal distribution of precipitation. This is affected by atmospheric pressure systems
-Seasonal distribution of rainfall, it’s reliability and it’s availability for use as a water source
Region with high variability of rainfall?
The Sahel
% of rainfall in the summer in the Sahel?
85%
Variations in mm of rainfall in the Sahel?
100mm in the edge of the Sahara to 800mm along its southern margins
Variation in the Sahel annulally?
Unusually warm sea surface temperatures in tropical seas favour strong convectional uplift over the ocean that, in turn, weakens the West African monsoon and contributes to drought in the Sahel
How does topography and distance from the sea affect supply of water?
High relief promotes increased precipitation and rapid run-off, but can also provide greater opportunities for surface water storage in natural lakes and artificial reservoirs
Example of where topography affects the supply of water?
Himalayas
Number of people affected by widespread melting of the cryosphere in the Himalayas?
500 million
How do river regimes affect water supply?
World’s major river systems store large quantities of water and transfer it across continents. Changes in weather patterns can lead to a decrease in the river discharge and the amount of water being available for communities
Annual discharge of the Amazon river?
175,000 cubic metres per second
When did drought occur in the Amazon and Brazil?
2005 and 2010
Deforestation argued as a contributing factor
How does geology affect water supply?
-Geology controls the distribution of aquifers that provide groundwater storage
-Permeable chalk and porous sandstones can store vast quantities of water underground, not subject to evaporation loss.
-The supply comes from springs and can be accessed by wells which can give an even supply throughout the year, providing it’s used sustainably
Areas with unpredictable monsoon seasons as a result of over abstraction of water from wells?
India and Pakistan
What does over abstraction of water from wells cause?
Falling water table and less availability
How do human actions affect the quality of the water supply?
-Pollute both surface and groundwater supplies. The impact of pollution is widespread but felt more in developing countries
-Groundwater contamination is potentially more serious if important aquifers are irreversibly damaged by the high levels of toxicity.
Some types of pollution include:
-Untreated sewage, causing typhoid and cholera
-Chemical fertilisers, causing eutrophication
-Industrial waster
Number who use contaminated water in China?
300 million daily
Number in China who suffer from water borne diseases annually?
190 million
Fraction of rivers highly polluted in China?
1/3
% of major lake and coastal region in China which are highly polluted?
75% lakes
25% coastal regions
Long-term how many in China suffer from water related diseases?
2 million
Which province of China is known to have ‘cancer cluster’ villages?
Guandong province
% of deaths caused by cancer in Guandong province?
90%
What caused the release of cancer toxins into the water supply in Guandong?
Release of heavy metal toxins from the Dabaoshan mine
% of unsafe wells in Bangladesh? Why?
20%
High concentrations of arsenic
Number of people in how many countries who have signs of arsenic poisoning from drinking water?
137 million people in over 70 countries
How does human activity affect the quantity of water supply?
-Over-abstract from rivers and lakes for domestic purposes, agriculture and industrial usage
-Removal of fresh water aquifers on coastal locations can upset the natural balance of saline and fresh water, leading to salt water incursion and salinisation of wells, boreholes and wetlands
-Energy industry needs increasing amounts of water for new energy developments such as biofuels and fracking
Projected water withdrawals for 2025 per year?
5000km3 per year
Fraction of water withdrawals to agriculture by 2025?
2/3
% of water use in agriculture both globally and in developing countries?
70% globally
90% in developing countries
Rise in GDP per year between 1960-2012?
3.5%
How has increasing GDP increased water demands?
income growth and rising living standards have led to an ever-increasing demand for water
% of freshwater withdrawals for energy production?
15%
% of freshwater withdrawal for thermal power and hydropower?
80% and 15% respectively
Describe salt water encroachment
1) Well drilled into sight of freshwater and extracted
2) Over time sea levels rise as the freshwater source is used up, drawing salt water up to the well
3) Continued extraction means salt water contaminates the freshwater meaning the water is no longer pure
% increase in global water demands by 2050 according to the UN water development report?
55%
% water deficit by 2030?
40%
% of waste water untreated and discharges in developing countries?
90%
