Hydromorphological and Morphometric Analysis of the Comoé River Basin (Côte d'Ivoire): Implications for Runoff and Erosion Processes

The Comoé River basin is one of the major hydrological units in Côte d’Ivoire, yet its hydromorphological dynamics remain insufficiently documented despite their importance for integrated water resources management. This study aims to characterize the morphometric and hydromorphological attributes of the main sub-basins of the Comoé and to assess their influence on runoff generation and erosion processes. The methodology is based on the use of an ASTER Digital Elevation Model (30 m) combined with Geographic Information System (GIS) tools to extract and analyse parameters related to basin shape, relief, and drainage network. Results indicate that the sub-basins are predominantly elongated (circularity index < 0.3), which results in relatively long concentration times and enhanced infiltration capacity. Drainage density (Dd < 1.5 km/km²) and stream frequency (F < 5) confirm the low potential for direct runoff, highlighting the predominance of infiltration processes. However, the Kafolo sub-basin, characterized by steeper slopes (global slope index = 0.54; mean channel slope = 1.43 m/km), shows higher susceptibility to erosion. By contrast, downstream sub-basins display depositional features, favoured by nearly horizontal longitudinal profiles (“lentic flats”). This study underlines the key role of morphometric parameters in shaping the hydrological and erosional response of the Comoé basin. It provides valuable insights for hydrological planning, erosion risk mitigation, and sustainable water resource management in the face of climate variability and increasing anthropogenic pressures.