fragile environments and climate change Flashcards
(27 cards)
what are fragile environments caused by
- desertification
- deforestation
- climate change
factors that affect our ecological footprint
- rate of population growth
- level of consumption of resources per person
- type of technology used
main characteristics of desertification
- absecnce of surface water
- dried up watercourse and ponds
- lowering water table
- vegetation degraded
- increases soil erosion
- increased salt content in soil
- soil becomes unusable
- increasing the presecne of dry loose sand
natural causes of desertification
- soil erosion
removal of top soil, less support - changing rainfall patterns
- intensity of rainfall
human causes of desertification
- population growth
- over cultivation
- over grazing
- migration
- deforestation
planting more trees- deforestation
- roots hold soil together
- reduces soil erosion
agroforestry
- intergrates high value multi purpose trees and shrubs into farming systems
- gives animals shelter, fruit trees, soil fertility
Riparian buffer zones
forested land adjacent to steams, rivers, marshes or shoreline which help prevent erosion and sedimentation.
- keeps river cool
bunding
- halting soil erosoin
- prevents run off, allowing rain water to percolate down
magic stones
circles of stones placed on the ground to hold water on the soil rather than letting run over the surface
drip irrigation
water drips slowly onto ground from pin-sized holes in a hose lying on top of the soil
- minimizes water loss
water management
water stores in dams during wet season and used to irrigate crops during dry season
desalination
taking salt out of water to make it drinkable.
- creates a reliable water supply
water transfers
systems of dams, reservoirs, pipes or canal to transfer large amounts of water from a donor basin to another
satellites
map progressing of desertification
GIS
find areas prone to frequent droughts
causes of deforestation
- commercial timber extraction
- agriculture
- mining
- transport
- settlement
- energy extraction
- land for farmers
impacts of deforestation
- loss of bio diversity
- climate change and global warming
- increased soil erosion
- benefit of economic development
to achieve sustainable management
- respect environment and cultures
- use traditional skills and knowledge
- give people control over lands
- use appropraite tech
- generate income for local communities
- protect biodivesity
sustaiable management in forestry
- protection of forests
- controlled logging
- restricting the number of logging licenses
- selective logging
- Heli logging
replanting forested areas - developing alternative energy supplies
- agroforestry
- substitution
- using satellites to monitor illegal logging
human causes of climate change
- deforestation
- use of fossil fuels and air pollution
- agricultural change
- use of CFCs
describe the greenhouse effect and then how it is ‘enhanced’
Step 1: Solar radiation reaches the Earth’s atmosphere - some of this is reflected into space.
Step 2: The rest of the sun’s energy is absorbed by the land and the oceans, heating the Earth.
Step 3: Heat radiates from Earth towards space.
Step 4: Some of this heat is trapped by greenhouse gases in the atmosphere, keeping the Earth warm enough to sustain life.
Step 5: Human activities such as burning fossil fuels, agriculture and land clearing are increasing the amount of greenhouse gases released into the atmosphere.
Step 6: This is trapping extra heat and causing the Earth’s temperature to rise.
natural causes of global warming
- solar output
- orbital changes
- volcanic eruptions
Milankovitch cycles
earths position varies slightly over a long time, as a result of cyclic predictable changes in earths orbit every 42000
