Floods result from the overflow of water which submerges the surrounding land. They are frequent on the coast of Côte d'Ivoire during the rainy season and have more or less serious consequences on the populations, property and the environment. The study site is the San Pedro river basin. It is a coastal catchment area characterized by an average annual rainfall of up to 2000 mm and subject to recurrent flooding. The objective of this study is to assess the risk of flooding during the great rainy season of 2017. The study aims to study flood hazard, assess vulnerability and map flood risk areas. The methodological approach is based on the use of C-band (5.6 cm) radar remote sensing data acquired by the Sentinel-1 sensor at 12-day intervals. These data are in GRD (Ground Range Detected) level 1 format and were used to calculate the radar backscatter coefficient. The results obtained allowed to map the extent of the flooded areas and showed that more than 6,000 ha of land is flooded for more than 3 days. Sentinel-1 has enormous potential to identify flooding risky areas and to continuously monitor them.

This study was carried out in order to determine the areas at risk of flooding during high water periods at the mouth of the Comoé River in Grand-Bassam. The database is essentially made up of hydro-climatic data, satellite images and topographic data. According to the various criteria, the Weibull law was selected to estimate the maximum frequency flows. According to this law, the flows at the return periods of 2, 10, 50 and 100 years are respectively 634, 733, 781 and 797 m3 / s. The modeling results showed that the areas exposed to the risk of flooding are located near the Ouladine lagoon and the Ebrié lagoon at the mouth of the Comoé river. The extent of the floodplains varies with flooded areas of the order of 85.63 km²; 89.42 km²; 101.67 km²; 107.10 km² for the return periods of 2; 10; 50 and 100 years old.

The Lobo reservoir, designed to supply water to the Daloa city population (central west of Côte d’Ivoire), is facing the phenomenon of eutrophication due to the agricultural plots located upstream of the reservoir inputs. Studies have highlighted the reservoir pollution and sedimentation problems. This study was initiated to test the effectiveness of a transfer model in the fight against the eutrophication problem. The objective of this study was to determine the optimal width of a vegetative filter strip on the banks of the Lobo reservoir, where the water intake installations of the drunk water company SODECI are located, using the VFSMOD model. The methodological approach is structured into four (4) main stages: 1—Evaluation of runoff from the source of pollution (contributing surface) during a rainy episode; 2—Calculation of the incoming runoff volume and the sediment load; 3—Simulation of runoff reduction and incoming sediments within the grassy filter strip; and 4—Determination of the optimal width of the grassy strip. The results obtained showed a contributing source area of 13.5 ha and 2% as the average slope. A runoff volume of 4680 m³ coming from the source of pollution is reduced by 1119 m³ (24%) through a grassy strip that is 3 m wide. The sediment load goes from 132 kg to 33 kg, a reduction of 75% in the quantity of sediment entering. The scenarios tested showed that a grassy strip width equal to 3 m should allow for a reduction of 75% of upstream sediments. This grassy strip width of 3 m should be considered for implementing a vegetative filter strip around the Lobo reservoir.

The Lobo reservoir designed to supply water to the Daloa city populations (Central west of Côte d'Ivoire) is facing the phenomenon of eutrophication due to the agricultural plots located upstream the reservoir inputs. Studies have highlighted the reservoir pollution and sedimentation problem. This study was initiated to provide a simple and effective solution to the eutrophication problem. The main objective is to determine the potential optimal dimensions of a grassed strip in order to limit the eutrophication phenomenon of the Lobo reservoir. The sizing of this grassed strip was done using the VFSMOD model. The flow from the pollution source plots was simulated and integrated into the model. The different scenarios tested from the band width variation have concerned the return periods of 1 and 2 years. The results obtained revealed that for the one-year return period, the grassed strip to be installed should have a width of 12.70 m in order to reduce by 70% the flow entering the strip considering the diffuse runoff over a length of 300 m. For the two-year return period, a width of 22.95 m should be required with the same length. The scenarios showed that a grassy strip width equal to 3 m should allow a reduction of 75% of upstream sediments.