Non daté
Central Africa and the Sahel
Traduction non disponible · Original (anglais) · français indisponible
The Lake Chad Basin is a major ecological and human-geographical region whose settlement patterns, agriculture, pastoralism, fishing, migrations, and political pressures are closely conditioned by geomorphology and climate. The excerpt describes its central depression, surrounding plateaux, alluvial zones, desert margins, and the historical retreat of cultivation before aridity. It presents the basin as a model case for integrating physical geography, environmental science, and historical inquiry.
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Le récit
The Lake Chad Basin is described as a central accumulation plain lying roughly between 180 and 300 metres in altitude, encircled by irregular weathered plateaux that average about 900 metres. Slopes connect these elevated areas to the lower plain, while erosion and climatic conditions influence the distribution of soils, vegetation, and human settlement. The resulting landscape is not uniform: fertile and better-watered zones contrast sharply with high plateaux and the increasingly arid northern margins.
Population density is highest in areas receiving rainfall and in Sahelian alluvial zones nourished by seepage or flooding from Lake Chad. The plateaux of Darfur and Adamawa, where tributaries rise, are more sparsely populated, while the Saharan north is still less densely occupied. Farmers, herdsmen, and fishermen are concentrated in the southern part of the basin, where lake and river water supports cultivation, pasture, and seasonal fishing.
Environmental pressures also shaped historical movements and social conflict. As the desert advanced, cultivation retreated toward areas where millet and sorghum could grow without irrigation, while irrigated crops remained possible along the Logone and Chari rivers. The passage further describes invasions that displaced farmers from fertile plains and plateaux into steep mountain environments, including the movement of the Fulani against the Bumi and Duru in Adamawa and the displacement of the Kiroi toward the Mandara massif.
Non daté
Central Africa and the Sahel
Traduction non disponible · Original (anglais) · français indisponible
The Lake Chad Basin is a major ecological and human-geographical region whose settlement patterns, agriculture, pastoralism, fishing, migrations, and political pressures are closely conditioned by geomorphology and climate. The excerpt describes its central depression, surrounding plateaux, alluvial zones, desert margins, and the historical retreat of cultivation before aridity. It presents the basin as a model case for integrating physical geography, environmental science, and historical inquiry.
Poursuivre l’exploration
Le récit
The Lake Chad Basin is described as a central accumulation plain lying roughly between 180 and 300 metres in altitude, encircled by irregular weathered plateaux that average about 900 metres. Slopes connect these elevated areas to the lower plain, while erosion and climatic conditions influence the distribution of soils, vegetation, and human settlement. The resulting landscape is not uniform: fertile and better-watered zones contrast sharply with high plateaux and the increasingly arid northern margins.
Population density is highest in areas receiving rainfall and in Sahelian alluvial zones nourished by seepage or flooding from Lake Chad. The plateaux of Darfur and Adamawa, where tributaries rise, are more sparsely populated, while the Saharan north is still less densely occupied. Farmers, herdsmen, and fishermen are concentrated in the southern part of the basin, where lake and river water supports cultivation, pasture, and seasonal fishing.
Environmental pressures also shaped historical movements and social conflict. As the desert advanced, cultivation retreated toward areas where millet and sorghum could grow without irrigation, while irrigated crops remained possible along the Logone and Chari rivers. The passage further describes invasions that displaced farmers from fertile plains and plateaux into steep mountain environments, including the movement of the Fulani against the Bumi and Duru in Adamawa and the displacement of the Kiroi toward the Mandara massif.