desertificationdesertification speaker: cheng jingxia group : 13 group : 13
TRANSCRIPT
DesertificationDesertificationDesertificationDesertification
Speaker: Cheng JingxiaSpeaker: Cheng Jingxia
Group : 13Group : 13
Contents
1. The current situation of desertification
2. The cause of desertification
3. The harm of desertification
4. How to prevent and control the
desertification?
Definition
Desertification is arid, semi-arid and
dry sub-humid areas of land
degradation , which caused by various
factors, including climatic variations
and human activities.
Current situation
Desertification is a worldwide
ecological environmental problem.
Over 100 countries were affected by
desertification. There are more than
12 million people have been
suffered the direct threat of
desertification. Although the
people of all countries are going to
fight against desertification, but
desertification is
expanding at
the speed of 50 to 70 thousand square
kilometers a year.
The global desertification has reached
36 million square kilometers,
accounting for 1/4 of the entire Earth's
land area,
which is equivalent to the sum of
the land area of Russia, Canada,
China and the United States.
Throughout the world, the
economic losses caused by the
desertification has reached 42
billion dollars each year.
In China
China is one of the countries which is the mos
t seriously affected by desertification. The ar
eas of desert, Gobi desert and desertification
land in China are about 1.7397
million square kilometers, the part of
modern desertification land caused b
y human activities is about 370,000 sq
uare kilometers, sand desertification
caused direct economic losses is mor
e than 54 billion yuan each year.
Desertification in China are
mainly distributed in Xinjiang and
Inner Mongolia, Tibet, Qinghai,
Gansu provinces.
The cause of desertification
1. Abnormal climate changing
2. Unreasonable land clearing
3. Overgrazing
4. Unreasonable dredging and tree felling
5. Water resources wasting
The harm of desertification
1. deteriorating the ecological
environment, affecting people's
lives, threatening human health.
2. Directly affecting agriculture,
production and life
3. Causing significant economic losses,
and impeding economic development
4. Exacerbating poverty level
Measures
1. Wind sheltering and sand fixation
2. Treating plants, expanding the
proportion of grass, building
protection system
3. Rational developing and utilizing of
water resources
4. Controlling the land reclamation,
protecting vegetation, non abusing
deforestation
5. Improving the protection of the legal
system, deepening the prevention
publicity and education.
6. Establishing a national
desertification prevention and
control team.
7. learning the advanced experience
about sand control from foreign
countries.
Sahara
It is the world's largest desert,
located in the south of the Atlas
Mountains and the Mediterranean,
west from the Atlantic Coast,
east to the Red Sea coast, across
the continent northern, up to 5600
km from east to west, north to
south width of 1600 km, the area
of
approximately 9.6 million square
kilometers, accounting for 32% of
the total area in Africa.
Governing desert is a long way to
go.
Need our unremitting efforts!