The Mlomp DSS site, about 500 km from the capital, Dakar, in Senegal, lies between latitudes 12°36′ and 12°32′N and longitudes 16°33′ and 16°37′E, at an altitude ranging from 0 to 20 m above sea level (Figure 25.1). It is in the region of Ziguinchor, Département of Oussouye, in southwest Senegal, near the border between Senegal and Guinea-Bissau. It covers about half the Arrondissement of Loudia-Ouolof. The Mlomp DSS site is about 11 km × 7 km and has an area of 70 km2. Villages are households grouped in a circle with a 3-km diameter and surrounded by lands that are flooded during the rainy season and cultivated for rice.