Human Impacts on Water Availability Flashcards
How and where does salt water incursion occur?
in coastal areas
due to over abstraction of groundwater
Over abstracting from aquifers can lead to what?
ground subsistence
untreated sewage can lead to what?
spread of disease e.g cholera
What is agriculture causing to happen to water supplies and ecosystems?
use of fertilisers / pesticides causing eutrophication
Define over abstraction
extraction and consumption of surface and groundwater resources beyond their sustainable level
abstraction > groundwater recharge
What happens during over abstraction
groundwater resources gradually become depleted
What problems in agriculture are causing water inefficiencies?
- evaporation
- seepage
- salinisation
- fertilisation
X2 technologies which could be introduced to decrease water inefficiency and contamination in agriculture;
- drip irrigation systems
- nitrate metres for soil to avoid over-fertilising
What global phenomenon means there is an increase in demand for water in industry?
industrialisation of BRICs
increasing proportion of middle class seeking to buy consumer goods / using more energy
What is happening to global domestic demand for water?
doubling every 20years
X3 reasons why global domestic demand for water is doubling every 20years
- increasing population
- increasing proportion of population can afford access to electricity
- globalisation meaning more people can access / afford consumer goods - so more demand - more water needed
What X3 water supply options are available;
a) surface water (rivers / lakes / reservoirs)
b) aquifers
c) desalination
How many dams globally
50,000
Dams collect what fraction of global fresh water supply
1/4
What X3 advantages to dams have?
+ short-term economic gains
+ opportunity for HEP
+ flood control
X2 disadvantages of dams
- environmental consequences
- social and economic cost of displacement
What fraction of Europe’s drinking water comes from aquifers?
3/4
Most of India’s water for irrigation comes from what?
aquifers
What X4 risks are there with over abstraction?
- ground subsistence
- falling water tables
- exhaustion of supplies
- salt-water incursion
Where is physical water scarcity concentrated?
north of the equator
e.g North Africa and southern Asia
Where is there little or no water scarcity?
Northern Hemisphere
What does most of South America suffer in terms of scarcity of water?
economic scarcity
California is home to how many of the USA’s largest cities?
X3
What did California do to secure water supplies?
Drain wetlands
which depleted fish stock and altered habitats
