Author(s)

Samassy Rokyatou Yéo¹, Kokoa Chia Marie Reine Allialy¹, Tano Anoumou Rene², Mondé Sylvain², Sangaré Seydou³, Kouadio Affian¹

¹Laboratory of Geology Mining Resources and Energy, Felix Houphouet Boigny University, Abidjan, Côte d’Ivoire.
²Laboratory of Fundamental and Applied Physic, Nangui Abrogoua University, Abidjan, Côte d’Ivoire.
³Department of Hydrography, Autonomous Port of Abidjan, Abidjan, Côte d’Ivoire.

The latest Intergovernmental Panel on Climate Change (IPCC) report shows that sea-level rise, which has been accelerated since the 19th century resulting to the global warming, threatens coastal areas with high population growth. A Global Sea Level Observing System (GLOSS) assessment highlighted the lack of data in Africa, and in Côte d’Ivoire in particular. In order to estimate the evolutionary trend of sea level along the Ivorian coast, and to draw up preventive plans to protect properties and populations, we digitized 65 years of historical tidegrams recorded in the Ebrie Lagoon, using the “Surfer” and “Nunieau” software, then processed them using “T-Tide” and “U-Tide” software. The average levels were calculated using the Demerliac filter from complete daily (day and night) recordings for providing a usable database of 31 years of hourly lagoon data from 1979 to 2015. Our results show that a mean water level in lagoon is 1.04 m. The evolutionary trend in sea level, estimated in the lagoon via the Vridi canal, during the rainy season is the most significant at 2.93 mm/year. This is followed by the dry season, with a trend of 2.89 mm/year. The flood season trend is 2.78 mm/year. This suggests that marine water inflows dominate continental inflows. Our results highlight the vulnerability of Côte d’Ivoire’s coasts to the risk of marine submersion.

Tide, Mean Water Level, Temporal Variability, Vridi Channel, Marine Submersion

Yéo, S. , Allialy, K. , Rene, T. , Sylvain, M. , Seydou, S. and Affian, K. (2023) Evolutive Trend of Water Level in the Ebrie Lagoon by Reconstitution of the Tide Gauge Time Series in Front of the Abidjan Coastline (Côte d’Ivoire). Journal of Water Resource and Protection, 15, 526-538. doi: 10.4236/jwarp.2023.1510029.