Water Lesson 11: Water Insecurity Flashcards
(48 cards)
% 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
