Sahel

Topic: World Physical Features and Natural Regions · NCERT: Beyond NCERT

Meaning

The Sahel is a semi-arid belt of grass, thorny shrubs and scattered trees along the southern edge of the Sahara. It stretches from Senegal and Mauritania on the Atlantic to Sudan and Eritrea near the Red Sea, and gets 200-600 mm of rain a year. Semi-arid means partly dry.

It matters because it is a transition zone between desert and savanna. Small changes in rainfall there lead to drought, desertification (good land turning into desert-like land), hunger and conflict. This makes the Sahel a well-known climate-conflict hotspot that keeps appearing in the news.

Explanation

Name and place in the climate pattern

• "Sahel" comes from the Arabic word for "shore" or "edge". It is the "shore" of the Sahara.
• It is a transition zone, a belt where one natural region slowly changes into another:
• North: the Sahara, a hot desert.
• Middle: the Sahel, with grass, thorny shrubs and scattered trees.

• South: the wetter savanna.

• Köppen climate class: the Sahel has a BS climate. BS means steppe or semi-arid: grassland that gets a little more rain than a true desert.

• A true desert like the Sahara is BWh, a hot desert. It usually gets less than about 250 mm of rain a year.

How the rain comes and why it fails

• Cause: the ITCZ moves with the seasons.
• The ITCZ (Inter Tropical Convergence Zone) is the low-pressure belt where the trade winds of the two hemispheres meet.

• In summer, the ITCZ moves north and brings rain to the Sahel.

• Process: one short wet season.

• All of the 200-600 mm falls in one short summer season.

• The rest of the year is dry.

• Result: rain the farmers cannot rely on.

• If the ITCZ does not move far enough north, the rains fail.
• Climate change is making rainfall more uneven.

How desertification happens here

• Causes:
• drought
• overgrazing by herds
• cutting trees for firewood

• farming poor soils

• Process:

• Plants that cover the ground are lost.
• Wind blows the topsoil away, or water washes it away.

• The soil holds less water.

• Result: the land can no longer grow crops or grass.

Problems that follow

• Recurrent drought:
• The worst drought was 1967-77. It caused famine and the death of large numbers of cattle.

• This drought led the world to set up the UNCCD (UN Convention to Combat Desertification, 1994).

• Food insecurity: poor harvests and a growing population mean many people do not have enough food.

• Conflict:
• Herders and farmers compete for shrinking land and water.
• Armed groups are active in the region.

• There have been military coups.

• Political split: after the coups, Mali, Burkina Faso and Niger formed the Alliance of Sahel States (AES). They left ECOWAS (Economic Community of West African States).

Where it occurs

• Countries of the Sahel, from west to east:
• Senegal and Mauritania on the Atlantic coast
• Mali, Burkina Faso and Niger
• northern Nigeria and Chad

• Sudan and Eritrea near the Red Sea

• To the north: the Sahara. It covers about 9 million sq km and runs from the Atlantic Ocean to the Red Sea. In the south it fades into the Sahel.

• To the south: the wetter savanna grasslands.
• Great Green Wall (the main restoration project in the Sahel):
• It is an African Union initiative launched in 2007 [1].
• It is a corridor of nearly 8,000 km from Senegal to Djibouti [1].
• It covers 11 countries [1]: Senegal, Mauritania, Mali, Burkina Faso, Niger, Nigeria, Chad, Sudan, Eritrea, Ethiopia and Djibouti.

• It began as a single line of trees. Now it is a mosaic (a patchwork) of restored forests, farms and grasslands.

• India link:

• The Thar (a hot desert in Rajasthan) and Ladakh (a cold desert) have problems like the Sahel's: sand dunes moving onto farmland, wind erosion and overgrazing.
• About 29.77% of India's area (97.85 million hectares) is degraded land or land turning into desert [3].

Don't confuse with

• Sahara: a true hot desert (Köppen BWh) with usually less than about 250 mm of rain a year. The Sahel is the semi-arid strip (BS) on its southern edge, with 200-600 mm.
• Savanna: the wetter grassland to the south of the Sahel. The Sahel lies between the savanna and the Sahara.
• Kalahari: also semi-arid, with grass and scrub, but it is in southern Africa (Botswana, Namibia, South Africa). The Sahel is in Africa north of the equator, just south of the Sahara.
• Great Green Wall vs Sahel: the Sahel is a natural region. The Great Green Wall is an African Union project (2007) [1]. It reaches Ethiopia and Djibouti, which are beyond the usual Sahel belt that ends at Sudan and Eritrea.

Prelims Hooks

• "Sahel" is Arabic for "shore" or "edge": the southern shore of the Sahara.
• Rainfall: 200-600 mm a year, in one short summer season. It depends on how far north the ITCZ moves.
• Extent: Senegal and Mauritania (Atlantic) to Sudan and Eritrea (Red Sea). Its Köppen class is BS (steppe or semi-arid), not BWh.
• Drought and treaty link: the 1967-77 Sahel drought led to the UNCCD (1994).
• AES: Mali, Burkina Faso and Niger formed the Alliance of Sahel States after military coups and left ECOWAS.
• Great Green Wall: African Union, 2007. It covers 11 countries from Senegal to Djibouti, about 8,000 km. The target is to restore 100 million ha by 2030 [1]. Trap: it is a mosaic of restored land, not just a single line of trees.

Mains Points

• The Sahel as a climate-conflict hotspot (GS-I/GS-III):
• The rains are uncertain because they depend on how far north the ITCZ moves. This leads to drought (as in 1967-77) and desertification.
• Desertification brings food insecurity and fights between herders and farmers over land and water.

• This instability fed into military coups, and Mali, Burkina Faso and Niger then left ECOWAS to form the AES.

• Great Green Wall: the policy response and its gaps (GS-III):

• The 2030 targets are to restore 100 million hectares, store over 300 million tonnes of CO₂ and create 10 million jobs [1].
• The first status report (September 2020) found close to 18 million hectares restored [1].

• To reach the goal, the countries would need to restore 8.2 million hectares a year, at about USD 4.3 billion a year [1]. The project is well behind target.

• Lessons for India (GS-III):

• India has pledged to restore 26 million hectares of degraded land by 2030 under the UNCCD [5].
• The National Action Plan to Combat Desertification, 2023 is built around this pledge [4].
• About 21.76 million hectares are already under restoration [2].
• The Thar and Ladakh can learn from the Sahel's mosaic approach, which joins land restoration with rural jobs.

Related concepts

• Sahara
• Atacama Desert
• Namib Desert
• Great Green Wall

Read more

• Deserts of the world and the Sahel