Desertification: Sahel

the causes, acceleration, consequences and management of desertification, including land use, conflict and climate change(One case study illustrating the human and physical dimensions of desertification)

Desertification

A type of land degradation in dry lands in which biological productivity is lost due to natural processes or induced by human activities; fertile areas become increasingly arid

Threatens 1/3 of our land

It takes 500 years to produce 2.5cm of coil

The Sahel Details

• belt running across Africa below the Sahara

• covers 10 countries including Senegal, Mauritania, Burkina Faso, Ethiopia, etc.

• 650,000km2

• wet season and dry season

Natural Causes of Desertification

drought

Human Causes of Desertification

• over-cultivation

• deforestation

• population increase

• overgrazing

• climate change

• water mismanagement

• fuel wood gathering → deforestation

Consequences

• food insecurity

• continued drought

• disease

Solutions/Mitigation

• zai pits → small hole in the ground, pile earth from hole at the side, fill hole with organic matter, divert water into hole, attracts termite, seeds are planted in the holes

• contour bunds → prevent rainwater from eroding land, hold moisture and nutrients in the land

• planting trees, forest management, removing lower branches and enhancing growth of crown of trees

• solar cookers

The Great Green Wall

• wall of trees stretching across continent of Africa

• spans 11 countries, mostly in Sahel

• 8000km long, 15km wide

• reversing deforestation = compost, canopy created, humidity, water retention in soil, filling wells

• expected to cost $8 billion

• since 2007

Agroecology

• eco-friendly farming

• intermediate technology

• biochar

• no-till farmin