Desertificati on Source : 九九九九九九九九九九九 (Hkedcity) 九九九九九九九九九九九九九九九九九九
Desertification Source : 九龍工業學校譚國新老師 (Hkedcity) 香港大學課程學系母語教學教師支援中心.
Jan 18, 2018
Desertification is intensification of desert-like condition in true desert areas (annual precipitation < 250 mm), or the extension of desert-like conditions into previously non-desert areas. This often takes place in semi-arid areas (annual precipitation between mm), e.g. Sahel region at the southern fringe of the Sahara Desert.
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Desertification
Source : 九龍工業學校譚國新老師 (Hkedcity)香港大學課程學系母語教學教師支援中心
1950 s
What are the changes on the landscape ？
1970 s
此照片摘取自新世紀世界地理百科全書
Desertification is intensification of desert-like condition in true desert areas (annual precipitation < 250 mm), or
the extension of desert-like conditions into previously non-desert areas.This often takes place in semi-arid areas (annual precipitation between 250 - 375 mm), e.g. Sahel region at the southern fringe of the Sahara Desert.
此照片摘取自新世紀世界地理百科全書
35
100
Precipitationmm
Temperature C
302520
50
It is a tropical grassland ( ) with equatorial and climate. Rainfall is (annual rainfall lies between mm and mm and rain mainly concentrates in summer.
Savannawet dry
scanty / low250 375
Based on the map of Africa, where
can we find desertification ?
薩赫勒地區Sahel region
Sahara Desert
Tropical rainforestequato
r
1950 60 70 80 90
500
1000 PopulationPasture 草地
Nomadic herding 牲畜
Precipitation mm
Time (year)
Climatic change
Population explosion
less rainfall
overcultivation
overgrazing
devegetation for firewood
as fuel
Soil erosion
dese
rtifica
ti
on
The End
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