SlideShare a Scribd company logo
1 of 25
Deforestation
&
DESERTIFICATION
A Serious and Daunting Problem……
SERIOUS THREAT..................
by
Dr. Jeevan Jyoti, PhD
Asst. Professor,
ACHS, Asmara
Whatis deforestation?
 Deforestation is the elimination of
forest and woodland areas on the
large scale.
Why is it a problem?
Deforestation causes problems on both
the ecological and evolutionary scales.
Ecological: Deforestation
eliminates key habitats that support highly
specialized and sensitive species, and
eliminates the Forests ability to act as
natural water and air filters.
 Evolutionary: With habitat loss
comes the loss of highly
specialized species, eliminating
often cause widespread
extinctions.
Current status
 Where is deforestation still a
problem?
 Developing countries.
 Tropical regions are at highest risk.
 Developed countries.
Causes
 Commercial Logging
 Agriculture
 Roads & Railways
 Forest fires
 Mining and drilling.
 Fuel-wood collection
 Residential living
space.
Preventive measures
 Plantation
 Alternate energy sources
Desertification
• The transformation of habitable land to desert, as
by a change in climate or destructive land use.
• Can be natural or human-induced.
• Desertification is regarded as an environmental
problem of global significance.
• Came to global attention about 30 years ago.
SOME FACTS
 Desertification is a worldwide
phenomenon causing land
degradation.
 It is mainly considered as a
combination of natural/ climatic
processes and human
interferences.
Regions effected by desertification
 Africa
 Central Asia
 Australia
 Regions in North and South America.
AREAS AT RISK FROM DESERTIFICATION
 Causes of Desertification
 Human activity
 Climatic changes (non-human
induced)
• Human Actions
•Overgrazing
• Inappropriate numbers or types of animals
• Trampling of soils
•Reduction of vegetative cover
•Deforestation
•Fuel wood gathering
•Land for farming.
• Overcultivation
•Economic incentives overriding agricultural
knowledge
•Population growth
• Estimates of percentage of human actions
causing desertification are:
• overgrazing (35%),
• Deforestation (30%),
• other agricultural activities (28%),
• Overexploitation of fuel wood (7%)
• Climatic Effects
• Natural global cycles of dry season and
rain fall.
• Less rain falls.
• Vegetation dies.
• Land becomes lighter colour and reflects
more light.
• Less rain means drier, more desiccated land.
• Topsoil dries and turns to dust, blows
away.
MAIN CAUSES FOR DESERTIFICATION
• Impacts: Ecological
• Accelerated soil erosion by wind or water
• Wind erosion can lead to huge dust storms.
• Dust can choke a city, bury an oasis, hasten
desertification in other areas.
• Reduction in species diversity
• Loss of animal and plant species
• Reduction in plant biomass.
Impacts: Economic
• Loss of fertility and productivity in soils.
• In China alone, about $6.5 billion annually
is lost to the effects of desertification.
• Worldwide $300-600 billion lost annually.
• Since 1985, Kazakhstan has lost 12.5
million acres of grain-growing land.
Impacts: Human
• Desert lands are inhospitable, sometimes not
habitable.
• 2/3 of habitable land in Africa at risk.
• Loss of land means increased poverty,
famine.
• Food insecurity leads to more environmental
refugees and displaced persons, more
forced migrations.
 Current Numbers
 Worldwide, desertification is making
approximately 12 million hectares
useless for cultivation every year. This
is equal to 10% of the total area of
South Africa.
 South Africa losing approximately 300-
400 million tons of topsoil every year.
 The Sahara desert is creeping
southward at a rate of 1km/year.
The Sahel regions are areas which experience
desertification.
Desertification is when a
desert gradually spreads to
the surrounding areas of
semi-desert.
Why?......
Sahelian Africa (CASE STUDY- THE SAHEL)
Sahel: A semiarid region of north-central Africa
south of the Sahara Desert.
The West African Sahel is the most seriously affected
region for desertification in the world. (severe drought
1968-1973).
Four main causes of desertification identified in the
Sahel: overcultivation, overgrazing, deforestation and
mismanagement of irrigation
Why does the Sahel suffer from desertification?
DESERTIFICATION
Increase in population Increase in cattle
Deforestation for fire wood Grassland grazed more intensively
Roots no longer hold soil together Roots may be eaten as well as grass
Leaves no longer protect soil from weather
Less vegetation means less protection from
weather
Loose top soil blown away by wind
(Soil Erosion)
=
Loose top soil blown away by wind
(Soil Erosion)
=
DESERTIFICATION
Preventive measures
 Tree planting
-Wind breaks
-Prevent erosion, trap airborne dirt
 Improved farming
-Less soil disturbance
 Alternative energy (to relieve fuel wood
pressure).
-Solar cookers for food
-Wind turbines yield energy and wind
breaks
26

More Related Content

Similar to DESERTIFICATION lect-8.pptx

Similar to DESERTIFICATION lect-8.pptx (20)

desertification..
desertification..desertification..
desertification..
 
Soil Degradation
Soil DegradationSoil Degradation
Soil Degradation
 
Group No 1( Deforestation).pptx
Group No 1( Deforestation).pptxGroup No 1( Deforestation).pptx
Group No 1( Deforestation).pptx
 
The deforestations in Romania
The deforestations in RomaniaThe deforestations in Romania
The deforestations in Romania
 
Desertification Group 3
Desertification Group 3Desertification Group 3
Desertification Group 3
 
Deforestation
DeforestationDeforestation
Deforestation
 
Shebin sheraf
Shebin sherafShebin sheraf
Shebin sheraf
 
desertification
 desertification desertification
desertification
 
DESERT
DESERTDESERT
DESERT
 
Deforestation in Bangladesh and its solution
Deforestation in Bangladesh and its solution Deforestation in Bangladesh and its solution
Deforestation in Bangladesh and its solution
 
Habitat loss
Habitat lossHabitat loss
Habitat loss
 
Deforestation and Climate change.pptx
Deforestation and Climate change.pptxDeforestation and Climate change.pptx
Deforestation and Climate change.pptx
 
Deforestation.
Deforestation.Deforestation.
Deforestation.
 
Deforestation.pptx
Deforestation.pptxDeforestation.pptx
Deforestation.pptx
 
Deforestation
DeforestationDeforestation
Deforestation
 
Agriculture and Ecosystem
Agriculture and EcosystemAgriculture and Ecosystem
Agriculture and Ecosystem
 
PRABAL PPT 4TH.pptx
PRABAL PPT 4TH.pptxPRABAL PPT 4TH.pptx
PRABAL PPT 4TH.pptx
 
Deforestation
DeforestationDeforestation
Deforestation
 
Deforestation and It's Effects
Deforestation and It's EffectsDeforestation and It's Effects
Deforestation and It's Effects
 
Presentation1
Presentation1Presentation1
Presentation1
 

More from Tejaskaushik2

Acid Rain lect-6.pptx
Acid Rain lect-6.pptxAcid Rain lect-6.pptx
Acid Rain lect-6.pptxTejaskaushik2
 
MAJOR AREAS OF ECOLOGY lect-2.ppt
MAJOR AREAS OF ECOLOGY lect-2.pptMAJOR AREAS OF ECOLOGY lect-2.ppt
MAJOR AREAS OF ECOLOGY lect-2.pptTejaskaushik2
 
Land (Soil) Pollution lect-4.pptx
Land (Soil) Pollution lect-4.pptxLand (Soil) Pollution lect-4.pptx
Land (Soil) Pollution lect-4.pptxTejaskaushik2
 
introductory lect-1 ento.ppt
introductory lect-1 ento.pptintroductory lect-1 ento.ppt
introductory lect-1 ento.pptTejaskaushik2
 
Economic importance lec-4.ppt
Economic importance lec-4.pptEconomic importance lec-4.ppt
Economic importance lec-4.pptTejaskaushik2
 
introductory lect-1 ento.ppt
introductory lect-1 ento.pptintroductory lect-1 ento.ppt
introductory lect-1 ento.pptTejaskaushik2
 
Ozone depletion lect-7.pptx
Ozone depletion lect-7.pptxOzone depletion lect-7.pptx
Ozone depletion lect-7.pptxTejaskaushik2
 

More from Tejaskaushik2 (7)

Acid Rain lect-6.pptx
Acid Rain lect-6.pptxAcid Rain lect-6.pptx
Acid Rain lect-6.pptx
 
MAJOR AREAS OF ECOLOGY lect-2.ppt
MAJOR AREAS OF ECOLOGY lect-2.pptMAJOR AREAS OF ECOLOGY lect-2.ppt
MAJOR AREAS OF ECOLOGY lect-2.ppt
 
Land (Soil) Pollution lect-4.pptx
Land (Soil) Pollution lect-4.pptxLand (Soil) Pollution lect-4.pptx
Land (Soil) Pollution lect-4.pptx
 
introductory lect-1 ento.ppt
introductory lect-1 ento.pptintroductory lect-1 ento.ppt
introductory lect-1 ento.ppt
 
Economic importance lec-4.ppt
Economic importance lec-4.pptEconomic importance lec-4.ppt
Economic importance lec-4.ppt
 
introductory lect-1 ento.ppt
introductory lect-1 ento.pptintroductory lect-1 ento.ppt
introductory lect-1 ento.ppt
 
Ozone depletion lect-7.pptx
Ozone depletion lect-7.pptxOzone depletion lect-7.pptx
Ozone depletion lect-7.pptx
 

Recently uploaded

Species composition, diversity and community structure of mangroves in Barang...
Species composition, diversity and community structure of mangroves in Barang...Species composition, diversity and community structure of mangroves in Barang...
Species composition, diversity and community structure of mangroves in Barang...Open Access Research Paper
 
Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...
Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...
Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...Amil baba
 
办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书
办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书
办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书zdzoqco
 
LESSON 1- Eyong Pantahanan at Pangkabuhayan.pptx
LESSON 1- Eyong Pantahanan at Pangkabuhayan.pptxLESSON 1- Eyong Pantahanan at Pangkabuhayan.pptx
LESSON 1- Eyong Pantahanan at Pangkabuhayan.pptxPascualJaniceC
 
BIODIVERSITY QUIZ ELIMINATION ROUND.pptx
BIODIVERSITY QUIZ ELIMINATION ROUND.pptxBIODIVERSITY QUIZ ELIMINATION ROUND.pptx
BIODIVERSITY QUIZ ELIMINATION ROUND.pptxROLANARIBATO3
 
EMP (Environment Management Plan . .pptx
EMP (Environment Management Plan . .pptxEMP (Environment Management Plan . .pptx
EMP (Environment Management Plan . .pptxSarmad Naeem
 
INSIDER THREAT PREVENTION IN THE US BANKING SYSTEM
INSIDER THREAT PREVENTION IN THE US BANKING SYSTEMINSIDER THREAT PREVENTION IN THE US BANKING SYSTEM
INSIDER THREAT PREVENTION IN THE US BANKING SYSTEMijsc
 
التغيرات المناخية وتاثيرها على القطاع الزراعي المصري
التغيرات المناخية وتاثيرها على القطاع الزراعي المصريالتغيرات المناخية وتاثيرها على القطاع الزراعي المصري
التغيرات المناخية وتاثيرها على القطاع الزراعي المصريRawhyaShaheen
 
Asexual-and-Sexual-Reproduction.huhupptx
Asexual-and-Sexual-Reproduction.huhupptxAsexual-and-Sexual-Reproduction.huhupptx
Asexual-and-Sexual-Reproduction.huhupptxMyBrightestStarParkJ
 
NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...
NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...
NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...Amil baba
 
Dwarka Call Girls 9643097474 Phone Number 24x7 Best Services
Dwarka Call Girls 9643097474 Phone Number 24x7 Best ServicesDwarka Call Girls 9643097474 Phone Number 24x7 Best Services
Dwarka Call Girls 9643097474 Phone Number 24x7 Best Servicesnajka9823
 
Group 4The Species of the Atlantic Forest.pdf
Group 4The Species of the Atlantic Forest.pdfGroup 4The Species of the Atlantic Forest.pdf
Group 4The Species of the Atlantic Forest.pdfs2015004
 
Research Methodology Book For New BS Student
Research Methodology Book For New BS StudentResearch Methodology Book For New BS Student
Research Methodology Book For New BS Studentiziaurrahmankhattak
 
毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree
毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree 毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree
毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree ttt fff
 
Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170
Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170
Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170simranguptaxx69
 
https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/
https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/
https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/dikjog
 
Making a Difference: Understanding the Upcycling and Recycling Difference
Making a Difference: Understanding the Upcycling and Recycling DifferenceMaking a Difference: Understanding the Upcycling and Recycling Difference
Making a Difference: Understanding the Upcycling and Recycling DifferenceSwag Cycle
 
Title-Role of forestry in restoration of degraded lands.pptx
Title-Role of forestry in restoration of degraded lands.pptxTitle-Role of forestry in restoration of degraded lands.pptx
Title-Role of forestry in restoration of degraded lands.pptxSagar Chaudhary
 
Call In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCR
Call In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCRCall In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCR
Call In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCRjennyeacort
 

Recently uploaded (20)

Species composition, diversity and community structure of mangroves in Barang...
Species composition, diversity and community structure of mangroves in Barang...Species composition, diversity and community structure of mangroves in Barang...
Species composition, diversity and community structure of mangroves in Barang...
 
Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...
Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...
Uae-NO1 Black Magic Specialist Expert In Bahawalpur, Sargodha, Sialkot, Sheik...
 
办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书
办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书
办理英属哥伦比亚大学毕业证成绩单|购买加拿大UBC文凭证书
 
LESSON 1- Eyong Pantahanan at Pangkabuhayan.pptx
LESSON 1- Eyong Pantahanan at Pangkabuhayan.pptxLESSON 1- Eyong Pantahanan at Pangkabuhayan.pptx
LESSON 1- Eyong Pantahanan at Pangkabuhayan.pptx
 
BIODIVERSITY QUIZ ELIMINATION ROUND.pptx
BIODIVERSITY QUIZ ELIMINATION ROUND.pptxBIODIVERSITY QUIZ ELIMINATION ROUND.pptx
BIODIVERSITY QUIZ ELIMINATION ROUND.pptx
 
EMP (Environment Management Plan . .pptx
EMP (Environment Management Plan . .pptxEMP (Environment Management Plan . .pptx
EMP (Environment Management Plan . .pptx
 
INSIDER THREAT PREVENTION IN THE US BANKING SYSTEM
INSIDER THREAT PREVENTION IN THE US BANKING SYSTEMINSIDER THREAT PREVENTION IN THE US BANKING SYSTEM
INSIDER THREAT PREVENTION IN THE US BANKING SYSTEM
 
التغيرات المناخية وتاثيرها على القطاع الزراعي المصري
التغيرات المناخية وتاثيرها على القطاع الزراعي المصريالتغيرات المناخية وتاثيرها على القطاع الزراعي المصري
التغيرات المناخية وتاثيرها على القطاع الزراعي المصري
 
Asexual-and-Sexual-Reproduction.huhupptx
Asexual-and-Sexual-Reproduction.huhupptxAsexual-and-Sexual-Reproduction.huhupptx
Asexual-and-Sexual-Reproduction.huhupptx
 
NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...
NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...
NO1 Certified Rohani Amil In Islamabad Amil Baba in Rawalpindi Kala Jadu Amil...
 
Dwarka Call Girls 9643097474 Phone Number 24x7 Best Services
Dwarka Call Girls 9643097474 Phone Number 24x7 Best ServicesDwarka Call Girls 9643097474 Phone Number 24x7 Best Services
Dwarka Call Girls 9643097474 Phone Number 24x7 Best Services
 
PLANTILLAS DE MEMORAMA CIENCIAS NATURALES
PLANTILLAS DE MEMORAMA CIENCIAS NATURALESPLANTILLAS DE MEMORAMA CIENCIAS NATURALES
PLANTILLAS DE MEMORAMA CIENCIAS NATURALES
 
Group 4The Species of the Atlantic Forest.pdf
Group 4The Species of the Atlantic Forest.pdfGroup 4The Species of the Atlantic Forest.pdf
Group 4The Species of the Atlantic Forest.pdf
 
Research Methodology Book For New BS Student
Research Methodology Book For New BS StudentResearch Methodology Book For New BS Student
Research Methodology Book For New BS Student
 
毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree
毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree 毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree
毕业文凭制作#回国入职#diploma#degree美国密苏里大学毕业证成绩单pdf电子版制作修改#毕业文凭制作#回国入职#diploma#degree
 
Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170
Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170
Call Girls Sarovar Portico Naraina Hotel, New Delhi 9873777170
 
https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/
https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/
https://www.facebook.com/people/Proper-Keto-Capsules-UK/61557989683758/
 
Making a Difference: Understanding the Upcycling and Recycling Difference
Making a Difference: Understanding the Upcycling and Recycling DifferenceMaking a Difference: Understanding the Upcycling and Recycling Difference
Making a Difference: Understanding the Upcycling and Recycling Difference
 
Title-Role of forestry in restoration of degraded lands.pptx
Title-Role of forestry in restoration of degraded lands.pptxTitle-Role of forestry in restoration of degraded lands.pptx
Title-Role of forestry in restoration of degraded lands.pptx
 
Call In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCR
Call In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCRCall In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCR
Call In girls Connaught Place (DELHI)⇛9711147426🔝Delhi NCR
 

DESERTIFICATION lect-8.pptx

  • 1. Deforestation & DESERTIFICATION A Serious and Daunting Problem…… SERIOUS THREAT.................. by Dr. Jeevan Jyoti, PhD Asst. Professor, ACHS, Asmara
  • 2. Whatis deforestation?  Deforestation is the elimination of forest and woodland areas on the large scale.
  • 3. Why is it a problem? Deforestation causes problems on both the ecological and evolutionary scales. Ecological: Deforestation eliminates key habitats that support highly specialized and sensitive species, and eliminates the Forests ability to act as natural water and air filters.
  • 4.  Evolutionary: With habitat loss comes the loss of highly specialized species, eliminating often cause widespread extinctions.
  • 5. Current status  Where is deforestation still a problem?  Developing countries.  Tropical regions are at highest risk.  Developed countries.
  • 6. Causes  Commercial Logging  Agriculture  Roads & Railways  Forest fires  Mining and drilling.  Fuel-wood collection  Residential living space.
  • 7. Preventive measures  Plantation  Alternate energy sources
  • 8. Desertification • The transformation of habitable land to desert, as by a change in climate or destructive land use. • Can be natural or human-induced. • Desertification is regarded as an environmental problem of global significance. • Came to global attention about 30 years ago.
  • 9. SOME FACTS  Desertification is a worldwide phenomenon causing land degradation.  It is mainly considered as a combination of natural/ climatic processes and human interferences.
  • 10. Regions effected by desertification  Africa  Central Asia  Australia  Regions in North and South America.
  • 11. AREAS AT RISK FROM DESERTIFICATION
  • 12.  Causes of Desertification  Human activity  Climatic changes (non-human induced)
  • 13. • Human Actions •Overgrazing • Inappropriate numbers or types of animals • Trampling of soils •Reduction of vegetative cover •Deforestation •Fuel wood gathering •Land for farming. • Overcultivation •Economic incentives overriding agricultural knowledge •Population growth
  • 14. • Estimates of percentage of human actions causing desertification are: • overgrazing (35%), • Deforestation (30%), • other agricultural activities (28%), • Overexploitation of fuel wood (7%)
  • 15. • Climatic Effects • Natural global cycles of dry season and rain fall. • Less rain falls. • Vegetation dies. • Land becomes lighter colour and reflects more light. • Less rain means drier, more desiccated land. • Topsoil dries and turns to dust, blows away.
  • 16. MAIN CAUSES FOR DESERTIFICATION
  • 17. • Impacts: Ecological • Accelerated soil erosion by wind or water • Wind erosion can lead to huge dust storms. • Dust can choke a city, bury an oasis, hasten desertification in other areas. • Reduction in species diversity • Loss of animal and plant species • Reduction in plant biomass.
  • 18. Impacts: Economic • Loss of fertility and productivity in soils. • In China alone, about $6.5 billion annually is lost to the effects of desertification. • Worldwide $300-600 billion lost annually. • Since 1985, Kazakhstan has lost 12.5 million acres of grain-growing land.
  • 19. Impacts: Human • Desert lands are inhospitable, sometimes not habitable. • 2/3 of habitable land in Africa at risk. • Loss of land means increased poverty, famine. • Food insecurity leads to more environmental refugees and displaced persons, more forced migrations.
  • 20.  Current Numbers  Worldwide, desertification is making approximately 12 million hectares useless for cultivation every year. This is equal to 10% of the total area of South Africa.  South Africa losing approximately 300- 400 million tons of topsoil every year.  The Sahara desert is creeping southward at a rate of 1km/year.
  • 21. The Sahel regions are areas which experience desertification. Desertification is when a desert gradually spreads to the surrounding areas of semi-desert. Why?......
  • 22. Sahelian Africa (CASE STUDY- THE SAHEL) Sahel: A semiarid region of north-central Africa south of the Sahara Desert. The West African Sahel is the most seriously affected region for desertification in the world. (severe drought 1968-1973). Four main causes of desertification identified in the Sahel: overcultivation, overgrazing, deforestation and mismanagement of irrigation
  • 23. Why does the Sahel suffer from desertification? DESERTIFICATION Increase in population Increase in cattle Deforestation for fire wood Grassland grazed more intensively Roots no longer hold soil together Roots may be eaten as well as grass Leaves no longer protect soil from weather Less vegetation means less protection from weather Loose top soil blown away by wind (Soil Erosion) = Loose top soil blown away by wind (Soil Erosion) = DESERTIFICATION
  • 24. Preventive measures  Tree planting -Wind breaks -Prevent erosion, trap airborne dirt  Improved farming -Less soil disturbance  Alternative energy (to relieve fuel wood pressure). -Solar cookers for food -Wind turbines yield energy and wind breaks
  • 25. 26

Editor's Notes

  1. Figure 1 : Waugh, D,1995
  2. Not induced by human actions, but can work in combination with them.
  3. Four main causes of desertification identified in the Sahel: overcultivation, overgrazing, deforestation and mismanagement of irrigation