Fragile Environments. What does it involve?. Management of soil erosion e.g. farming practices. Consequences. The fragile nature of environments/ concept of sustainability. Causes of soil erosion & desertification. Case study Sahel. Causes. Case study Amazon. Management. Deforestation.
Management of soil erosion e.g. farming practices
The fragile nature of environments/ concept of sustainability
Causes of soil erosion & desertification
Case study Sahel
Case study Amazon
Case study: Bangladesh
Named egs of causes/
Greenhouse effect and global warming
Examples of solutions eg Kyoto
This is NOT the Carbon footprint – how is it different?
Dark Green have an OK footprint– does not look good for the rest of us! Red is seriously bad, orange and yellow still above the world average; both greens are below average (2.7 hectares per person), but only dark green is less than the planet can stand (1.8 hectares)
What is a biome?
Why do I say that?
One of the major problems in fragile environments
Where removal by removal of portions of the soil by various means so that fertility of the soil is reduced
Raindrop impact is the major cause of soil particle detachment which can result in the particles moving down slope as sheet erosion during a rainfall event.
Sheet erosion is the removal of fairly uniform layer of surface material from the land surface by continuous sheets of runoff water rather than concentrated into channels.Sheet Erosion
While it causes severe erosion, it is very difficult to see, as the amount removed is often slight from any particular spot. Notice how these ploughed areas in Romania have been covered by the sheet erosion.Sheet Erosion
Erosion involves the picking up and blowing away of loose fine grained material within the soil.Wind erosion
Crop damage, especially of young crops, can be serious.
Either the roots are exposed as the wind blows away the top soil or else wind blown soil from elsewhere cover the seeding up – either way the crop will be lost.Short-term effects of wind erosion
Finer soil fractions (silt, clay, and organic matter) are removed and carried away by the wind, leaving the coarser fractions behind.
This sorting action not only removes the most important material from the standpoint of productivity and water retention, but leaves a more sandy, and thus an even more erodible, soil than the original.Long term effects of wind erosion
Why is it like that?
What are the impacts of desertification on the people?
How can it be managed for the future?
Michael Buerk: A famine of biblical proportions in the 20th century …