Study area and in situ data

The study site lies in the north-western part of Burkina Faso in the Kossi district to Mali’s border. In the centre of this area, the city of Nouna is located at 12° 44‘ N; 3° 51‘ W. Approximately 20,000 inhabitants live in Nouna town and 50,000 other live in sixty villages around.

Most areas in this region lie on an altitude of 150-250m above the sea level and belong to a Precambrian peneplain.

Sandy soils and less dense vegetation characterize the northern zone, facing the Sahel. In effect, the south receives higher rainfall, and presence of clay and silt promotes surface water. Study area is located in the Sudano-Sahelian zone where malaria is endemic but dependent on rainfall. Mean precipitation for Nouna during the last 10 years has been 817 mm per year. The monthly maxima during the rainy season between May and September can reach up to 350 mm. The yearly average temperature of Nouna is 27.8°C. From March to May, temperatures are higher and can exceed 45°C during the day, while rainfall and hence vegetation are minimal.

Majority of the population depends to agriculture and lives in extreme poverty: 27.2% of the population lives below the poverty line fixed to $1 a day (World Bank, 2008)..

Nouna area northwest Burkina. Villages, roads hydrography and population density. Based on geographic and demographic system of the- CRSN, Nouna, 2009