Simultaneous Effects of the Climate Change and the Recent Hydromorphological Modification of Vridi Channel (Côte d'Ivoire) on Some Its Hydrochemical Characteristics

Abstract

This work aims to assess the simultaneous effects of the climate change and the hydromorphological modification of Vridi channel on its hydrochemistry. To best estimate, this fact, the seasonal dynamic of the particle size distribution, pH, redox potential, salinity, conductivity, moisture and organic matter contents of Vridi channel sediments have been followed and compared during two different annual periods, where the climate and the hydromorphology of this estuary have been different. The first annual period, covering the period from April 2014 to March 2015, has been characterized by a climatic regime close to the climatic normal of the study area and, this channel had its former hydromorphology. The second period annual, covering the period from October 2018 to September 2019, has been marked by a disruption of the climatic regime throughout Côte d'Ivoire, and this channel presented its modified hydromorphology.
 A monthly sampling has been done in this channel during each annual period. All These physical and chemical parameters have been determined by the corresponding AFNOR standards.
 Results have shown that these superficial sediments, with a predominantly sandy texture over the period from April 2014 to March 2015, have presented a texture predominantly of silt and clays over the period from October 2018 to September 2019. The climate change and the recent hydromorphological modification of this ecosystem had simultaneous very few effects on their pH and redox potential over the study period. On the other hand, they have caused an important increase in their salinity, moisture and organic matter contents and, a decrease in their electrical conductivity over the period from October 2018 to September 2019 relative to those determined in these substrates over the period of April 2014 to March 2015. This fact has certainly affected its biodiversity, especially that of its benthic fauna.

Impact of the Climate Change and the Recent Development of an Artificial Tropical Estuary on the Mobility and Distribution of Phosphorus: Case of Vridi Channel (Côte d'Ivoire)

“…As in the case of the physical and chemical parameters assessed by N'Da et al [34], the climate change and the recent development of Vridi channel led to a general decrease in the carbonates and ETM contents, as well as the different P fractions considered in this study. So, the present hydromorphological configuration of this artificial estuary, with the support of the climate change, is similar to a purifier of pollutants from Ebrié system towards Atlantic Ocean in front of Abidajan district.…”

“…This fact has impacted its hydrochemical functioning. This was illustrated by the recent study of N'Da et al [34], who have shown that the simultaneous impacts of this development with the climate change on the seasonal dynamics of pH, redox potential, conductivity, salinity, particle size distribution, moisture and organic matter contents of its superficial sediments. This would certainly have an effect on the biodiversity of this aquatic ecosystem, in particular on its flora and benthic fauna.…”

“…Those relating to P form contents in the superficial sediments of Vridi channel over the period from April 2014 to March 2015 were taken from the studies of N'Da et al [3]. The annual mean values (m±s (VC (%)) of pH, redox potential, salinity, conductivity, organic matter and moisture contents of these surface sediments over these two annual periods come from the recent studies of N'Da et al [34] (Table 2). 3.…”

Contribution to the Study of Phosphorus Adsorption Kinetics on the Superficial Sediments of a Recently Development Artificial Estuary: Vridi Channel (Côte d'Ivoire)

“…This is also the case for their phosphorus contents, which experienced a real drop with this development. On the other hand, this development has very little influence their pH [14,19].…”