Variables | Guinean zone | Sudano-Guinean zone | Sudanian zone |
---|---|---|---|
Altitude (in m) | 56–223 | 153–308 | 214–609 |
Annual rainfall (mm) | 1200–1500 | 1100–1300 | 900–1100 |
Temperature (°C) | 24–30 | 25–34 | 21–35 |
Seasons | Bimodal rainfall regime: 2 dry seasons and 2 rainy seasons | Bimodal rainfall regime: 2 dry seasons and 2 rainy seasons | Unimodal rainfall regime: 1 dry season and 1 rainy season |
Dominant soils | Ferrallitic soils | Ferruginous and ferrallitic soils | Concreted or hardened ferruginous soils with small deep |
Number of surveyed villages | 20 | 19 | 11 |
Surveyed sociolinguistic groups | Biali (Exotic), Somba (Exotic), Fon, Holly, Mahi, Nago, Idaasha | Adja, Fon, Holly, Mahi, Nago, Yoruba | Bariba, Dendi, Peuhl, Yoruba (Exotic), Boo |