The Sapone DSS is located in the centre of Burkina faso, 40 km at the south from the capital, Ouagadougou in the Sudan-Sahelian eco-climatic zone (isohyets 600-800). The DSS covers an area of 1700 Km2. As in the rest of the country, the topography is rarely uneven; it consists of a plateau dissected by the Nazinon, one of the most important rivers of the country which run up to Ghana. The mean temperature recorded during the twenty five years is 28.5° C and the mean rainfall for the same period goes up to 724.3 mm. The climate is characterized by a rainy season from June to September and dry season from October to may (cold from December to February, hot from March to May).