Contribution of Geomatics to the Delimitation of Protection Perimeters: Case of Agbo River in Agboville (South-East of Côte d’Ivoire)

Abstract

The present study aims to delimit protection perimeters around the “Agbo” river in Agboville in order to reduce the risks of pollution of this water resource. The methodological approach consisted first all in assessing the vulnerability of the resource and then in determining the protection perimeters based on the vulnerability map and previous studies. Five parameters (slope, land use, soil type, annual runoff and drainage density) were used. These parameters were then weighted using the Saaty multicriteria analysis method. The vulnerability map reveals four classes (very low, low, medium and high) with a dominance of the low class (41.35% of the area). Three protection perimeters were delineated (immediate, close and remote). The immediate protection perimeter is delimited at a distance of 200 m around the SODECI water intake on the “Agbo” river and covers the areas with a strong influence on the vulnerability to pollution of the river. The closer protection perimeter at a distance of 1000 m, is represented by the zones with strong influence on the vulnerability of the resource and the direction of water flow in the watershed. Finally, the remote protection perimeter covers a large part of the catchment area with a surface area of 510.36 km2 and takes into account the zones that have an influence on the vulnerability to pollution of the resource. These delimited protection perimeters can serve as a guide for the management and protection of the water intake in Agboville as well as for land use planning in this area.