Year: 2025 | Month: April | Volume: 12 | Issue: 4 | Pages: 368-374
DOI: https://doi.org/10.52403/ijrr.20250444
Numerical Modelling of the Evolution of Sedimentary and Topo-Bathymetric Transit Rates: The Case of the Beaches of Rufisque on the Small Senegalese Coast
Madièye Fall1, Déthié Sarr1, Hamed FALL1, Oustasse Abdoulaye Sall2
1Geotechnical Engineering Department, L2M, University Iba Der Thiam of Thies, Senegal.
2Civil Engineering Department, L2M, University Iba Der Thiam of Thies, Senegal.
Corresponding Author: Madièye Fall
ABSTRACT
This study seeks to estimate by a numerical approach the average rate of sediment transit along the sandy beaches of Rufisque on the small Senegalese coast, and to study its longitudinal variability as a function of this beach. The transit estimation approach is based on the long-term analysis, between 1985 and 2021, of the topo-bathymetric evolution of the seabed. By using remote sensing methods and Geographic Information Systems, the quality of the bathymetric data allows the implementation, and during each period, of a Digital Depth Model (DEM). The superposition of two Numerical Depth Models allows the calculation of the volumes of sand corresponding to the surfaces in erosion or accretion, of the sediment balances and by deduction of the average rates of sediment transit. The method used in this work shows that as a function of the behavior of the beaches, which are more or less dissipative and reflexive, the average rate of longitudinal transport by the coastal drift is inversely proportional to the dissipation capacity of the wave energy of the beach. During the study period, the Rufisque sector recorded significant erosion at the level of cells 1, 2 and 4 with respective average rates of -3.56,103 m3/year, -4.18,103 m3/year and -3,67,103 m3/year, while at the level of cell 3 a positive sediment balance was recorded, meaning an accumulation with an average rate of +1.13,103 m3/year.
Keywords: Digital Depth Model, sedimentary transit, morphodynamic index, remote sensing, GIS.
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