**2. Presentation of the Kayanga/Geba catchment area**

The Kayanga/Geba watershed is a transboundary basin (**Figure 1**) shared by Guinea (1.3% of the total area), Senegal (34.3%) and Guinea-Bissau (64.4%) [7, 8]. The river has its source in the western part of the Badiar Plateau (Guinea), in swamps, at an altitude of about 90 m. It flows northwest for about 10 km, passes through Senegal as it flows west and then southwest, enters Guinea-Bissau after a course of about 150 km and takes the name Rio Geba [9]. The South Sudanese climate is characterised by a rainy season from May to October and a dry season for the rest of the year. The latitudinal configuration of the basin shows rainfall contrasts with an average annual rainfall of about 1000 mm in the north and 1500 mm in the south. Average monthly temperatures range from 23.7°C in December to 31.7°C in May. The average monthly temperature ranges from 23.7°C in December to 31.7°C in May at the Kolda station. In this basin, agriculture remains the main activity and source of income for the predominantly rural population. The other socio-economic activities such as the livestock, the continental fishing, the arboriculture, the market gardening and the trade are also

*Water Control, Impacts and Sub-Regional Cooperation around a Transboundary Hydrological… DOI: http://dx.doi.org/10.5772/intechopen.105698*

### **Figure 1.**

*Location of the Kayanga/Geba River watershed [7].*


### **Table 1.**

*Distribution of the basin population by country.*

developed there. However, they are submitted to hydro-rainfall variations [7]. The total population of the basin is estimated at 760,000 residents, of which 0.4% live in Guinea, 41.8% in Senegal and 57.8% in Guinea-Bissau (**Table 1**) [10].
