TITLE:
Morphometric Characterization of the Watersheds of the Main Water Bodies in the Peri-Urban Area of Dakar Using GIS and Remote Sensing: The Case of the Mbao Stream, Lake Mbeubeuss, and Lake Rose
AUTHORS:
Christelle Musique Mendy, Louis Eugène Victor Sambou, Coumba Ndiaye, Essomanam Marius Pignandi, Saïdou Ndao
KEYWORDS:
Watershed, Morphometry, GIS, Prioritization, Drainage Density, Hypsometry, Urban Hydrology, Hydrological Vulnerability, Dakar
JOURNAL NAME:
Open Journal of Modern Hydrology,
Vol.16 No.4,
September
28,
2026
ABSTRACT: The watersheds of Dakar’s peri-urban water bodies are undergoing significant urban transformation, yet their morphometric characteristics remain poorly documented. To address this, this study provides a detailed morphometric characterization of the watersheds of the Mbao backwater, Lac Rose, and Lac de Mbeubeuss, using advanced Geographic Information System (GIS) tools. The delineation of the watersheds and the extraction of the hydrographic network were performed using the 30-meter SRTMGL1 v003 dataset processed in ArcGIS 10.7. After hydrological conditioning of the elevation model, selection of outflow points, and extraction of the network at a threshold of 500 cells (0.45 km2), the linear, shape, relief, and hypsometric parameters were calculated. The extracted networks are of order 3 to 5, and their drainage densities range from 1.02 to 1.22 km/km2. Shape factors ranging from 0.29 to 0.51 and Gravelius compactness coefficients ranging from 1.44 to 1.69 indicate generally elongated basins. The Lake Rose basin has the largest surface area and the most developed drainage network, while Lake Mbeubeuss has the flattest topography. These results indicate low channelization at the selected threshold and provide a morphometric basis for hydrological analysis and water body management. However, their interpretation remains limited by the SRTM’s resolution, sensitivity to the threshold, low relief, and incomplete representation of urban drainage.