Year: 2024 | Month: April | Volume: 11 | Issue: 4 | Pages: 41-49
DOI: https://doi.org/10.52403/ijrr.20240405
Study of the Risks of Overflow and Salinization of the Mbao Backwater: Impact on Local Populations
Saidou NDAO1,2, Famara Seydi BA1,2, Louis Victor Eugéne SAMBOU1,2
1Laboratory of Water and Environmental Sciences and Technologies (LaSTEE), Ecole Polytechnique of Thiès, Thiès, Senegal
2 Faculty of Science and Technology, Iba Der Thiam University of Thiès, Thiès, Senegal/p>
Corresponding Author: Saidou NDAO
ABSTRACT
The Mbao backwater, located in the Mbao forest in Dakar, plays an important role in income generation and flood prevention for the localities of Pikine, Keur Massar and Rufisque. Today, it is increasingly threatened with the risk of overflow due to the considerable reduction in its storage capacity and the arrival of large quantities of runoff water from the watersheds of which it is the outlet. In addition, its salinization is noted due to its proximity to the sea. The objective of this article is to present the results of the study of the risks of overflow and salinization of the Mbao backwater and their impacts on socio-economic activities. After modelling the volumes of water received by the backwater using the EPASWMM software and a study of its vulnerability to saline intrusion during high tides, It emerged that in the event of a decadal rainfall of the Desbordes type in the area, an overflow of 1,001,758 m3 could be noted, causing flooding and inconvenience to the local populations. In addition, a connection between the waters of the sea and those of the backwater causes salinization of the latter, negatively impacting the market gardening activities carried out by local residents. A pumping system at 1,500 m3/h could help prevent the backwater from overflowing, and the construction of a weir dam between the sea and the backwater would help control the salinization of the downstream part.
Keywords: risk, overflow, salinization, vulnerability, Mbao backwater
[PDF Full Text]