Morphometric parameters of Vranso watershed (Burkina Faso, West Africa) and their influence on the site's potential recharge

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Résumé

The response of a hydro-system to rainfall, is influenced numerous parameters, including morphometric features. Thus, knowing the characteristics of a watershed enables better management of risks and water resources. However, studies of West African drainage systems, particularly in Burkina Faso, rarely use morphometric parameters. In this context, the study of Vranso watershed contributes to better understanding of the functioning of the country's watersheds. To reach this objective, various morphometric indexes, including linear, shape, and relief parameters, were quantified using data from the Digital Elevation Model of Alaska Satellite Facility. Parameters extraction, measurements, and displays were performed using a Geographic Information System software, and calculations were performed using a spreadsheet program. Based on the obtained results, Vranso watershed is classified as seventh order. Its circularity index (0.13), elongation index (0.51), shape factor (0.42), and Gravelius coefficient (2.73) indicate that it is elongated. The calculated texture ratio (1.3), bifurcation index (3.5), flow frequency (0.24), infiltration factor (0.2), drainage density (0.84), and integral hypsometric relief index (0.2) suggest that the basin offers a significant capacity for the infiltration and recharge of its aquifers, a process that is facilitated by the connection between streams and tectonic structures.

Mots-clés

Burkina Faso, DEM, Morphometric parameters, Recharge, Vranso, Watershed