Resource security notes from online lessons Flashcards
(154 cards)
What factors effect water supply?
Topography - Long narrow valley -Small surface area- less evaporation
Reliable/High water flow- catchment area
Geology (impermeable)-
Catchment area
Climate - sufficient rainfal
What are the impacts of reservoirs?
Downstream- less sediment to deltas- more coastal erosion, less soil fertility/ecosystems
Micro climates- higher rainfall over reservoir lower ground
Floodland-
Flood control
Stored water supplies/miscellaneous benefits
Sedimentation rescues capacity
Micriclimate
Alters river regime downstream:changes flow; habitat change; landform change
Aquifer:
: area of porous rock saturated with water. Form in sedimentary basins with layers of permeable and impermeable rock, can be confined or unconfin
What are the impacts of over-abstraction?
Subsidence
Sinking of water table: loss of wetland; increasing unreliability of rivers
Salt water intrusion
Drying of soils
Human: impacts on agriculture, pumping costs etc.
What is water surplus:
Areas where there is more than sufficient water available to meet human need
Why is global demand for water rising?
Population increase and economic development
Water security:
capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for: sustaining livelihoods; human well-being and socio-economic development; ensuring protection against waterborne pollution or water-related disasters; preserving ecosystems in a climate of peace and political stability
Water stress:
– annual supply of water per person is less than 1,700m3. Demand for water has exceeded the amount of water available or poor quality water has restricted the amount available.
What is Water scarcity and give an example of where this takes places?
Below 1,000m3/per person/year
Northern africa and middle east
What is Absolute water scarcity and give an example of where this takes places?
Below 500m3/per person/year
Northern Africa and middle east
What is physical scarcity and give an example of where this takes places?
More than 75% of river flows being used/natures provisions of water is insufficient to meet populations needs. Less than 500mm of rainfall annually
Northern Africa and middle east and central Asia
What is economic scarcity and give an example of where this takes places?
Human and financial factors limit water use to less than 25% of river flow
Sub saharan african
Southern Asia
South America
What characteristics allow for water surplus?
Low evaporation rates
Infrastructure to meet needs
What are the physical factors that affect water supply?
give an example for each
Climatic:
- Precipitation levels
- Evaporation rates
Geological
- Permeability of rocks
Drainage
- Capacity and size of drainage basin system
What are the human factors that affect water supply?
Demand levels (human activities) Environmental controls (levels of pollution/human activities) Management systems - who sells water
Name some successful transboundary agreements?
Mekong River Commission Jordan River (israel and Jordan) Indus River Commissions 1999 Nile River Basin Agreements 1987 Syria and Turkey agreement
What is water diversion?
Changing the course of the river so it flows to a different area
Why was the water diverted?
Aral Sea
For use in the soviet union
To create cotton farms
What were the environmental impacts in the Aral Sea?
In the desert ½ the water evaporates
Poisonous and deadly chemicals used
The sea has dried up completely
The water left is full of chemicals and salt
Only 4 of of 38 types of fish are left
So much salt in ground- water pipes have to be built above ground.
The whole region is seeing an increase in high temperatures
What were the economic impacts in the Aral Sea?
The local people rely on the cotton for jobs
Local fishermen cannot sell to local factories
What were the human welfare impacts in the Aral Sea?
One village has water for 25 minutes a day Not enough water for villagers No food for villagers Fishing villages no longer by water Docks 50km from the water edge
What were the supply problems in the Aral Sea?
Not enough water to the local people
People with typhoid has gone up 29 x
15,000 people has left the village
Food supplies have gone down
Poor health
83% of children have a illness - chemicals affecting breast milk
More premature baby and more miscarriages
What is water transfer?
Moving water areas of surplus to area of shortage, usually pumped through pipes, channels, canals and aqueducts
What is the South-to-North water transfer project?
Large scale water transfer scheme in china