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Matilde Lima

on 30 April 2010

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Transcript of Desertification

What is it? Desertification is the extreme deterioration of land in arid and dry sub-humid areas.
Some examples are: Semi-arid regions of southern California Madagascar's central highland plateau Gobi Desert Sahara Desert Nowadays desertification is expanding at an alarming rate, and the causes for this expansion tend to be:

man-made activities
climatic variations
overdrafting of groundwater
diversion of water from rivers for human consumption and industrial use
As expected desertification has its impacts;

animal extinction
distruction of habitats
global warming
loss of productive capacity
As expected desertification has its impacts;

animal extinction
destruction of habitats
global warming
loss of productive capacity
IN PORTUGAL Portugal faces the risk of desertification.
Above Tejo river the risk is pratically zero.
Alentejo and Algarve suffer great pressure due to lack of rainfall, overgrazing and farming (Alentejo), and too many tourist infrastructures (Algarve).
In order to solve the lack of rainfall in Alentejo, the Alqueva dam was built - largest lake that would:

irrigate the surrounding farmland
no use of primitive sources of water
percentage of soils in risk of desertification reduced

In the Algarve, due to the golf courses and other tourist infrastructure such as swimming pools, the Portuguese government implemented some policies in order to restrict water use for these activities. Desertification in Portugal GoBI DESERT The Gobi desert is a large desert region in inner Mongolia, Asia. It covers parts of northern and northwestern China, and of southern Mongolia.

The Gobi is a rain shadow desert formed by the Himalaya range blocking rain-carrying clouds from reaching the Gobi.
Currently, the Gobi desert is expanding at an alarming rate - desertification.

each year - 3600km2
since 1949 - greenland's area
The physical landscape of Alashan region used to be green, filled with trees and bushes with beautiful grassland and big lakes prior to the problems of desertification.

human activities,
notably deforestation (saxsol trees),
extense harvast,
over ploughing,
depletion of water resources,
over population because of the influx of poor people.

China has made various plans to try to slow the expansion of the desert but usually have no major impact - restore forty million

One iniciative was tree-seeding - 1.4 million hectars of trees
The trees would then have to be protected by fences however they would then stop being a resource for the communities. The government would replace the saxsol trees by expensive and time-consuming biogas, solar and wind power energies.
Green Wall of China
Fifth Largest No SUCCESS WHY? HUGE INCREASE ...they still have... HOPE DUST storms
Full transcript