Spatial and Temporal Variation of the Hydrological Parameters in the Wouri-Nkam Section of the Cameroon Estuary, Central African Atlantic Coast

Abstract

This study aimed to provide relevant knowledge about the dynamics of the hydrological parameters in the river-estuary continuum of the Wouri-Nkam river estuary for a sustainable management program. The hydrological parameters were recorded in eleven stations spanned out on the basis of population density and human activities. Water quality parameters (Temperature, salinity, dissolved oxygen, pH, Total dissolved solutes, Redox potential and conductivity) were collected in subsurface water using a multiple parameter. Surface currents and morphometric (depth and width) parameters were recorded using a drifter, sonar depth and GPS. The field measurements took placed between 18/05/2019 to 08/09/2020 and were divided into six (06) cruises. The data were later subjected to an analysis of variance (ANOVA) and Principle Component Analysis using XLSTAT 2017 (2.7 version) software. Results obtained revealed that, the water quality parameters were spatially more stable not signficant at (df = 9, p < 0.05) with a relatively low temperature (25.5˚C -27˚C) during the wet period. The limit of the frontal zone extended to S5 (Bonalokan, 8.25 km from S1) during the snapshot of the dry period, spring phase and flood tide conditions. Inversely, during wet period, this extension reduced to S1 (Bridge) and relatively increases slightly to S3 (Bonangang) during the neap phase and ebb tides of this season. This result revealed a change in the axial gradient of about eight (08)

Salinity Distribution in a Tropical River-Estuary Continuum through Numerical Modelling: Case of the Wouri-Nkam River Estuary, Cameroon

“…5 indicate that the studied area is separated into two sections: the lower Oligohaline section, which has relatively higher salinities values (salinity > 0.5 psu) and the upper Limnic section, which has lower salinity values (salinity < 0.5 psu). This confirms that the study area corresponds to the upper estuary, where fresh riverine water and brackish estuarine water combine with tidal dominance and riverine influence (Besack et al 2021). This work also underscored that the oligohaline boundary changes with season and tidal conditions.…”

Effect of Tide on Temporal and Spatial Distribution of Some Physical and Chemicals Parameters in the Shallow Estuary of the Kienke River (Kribi Deep Sea Port Area, South Cameroon Coast)

“…These results also showed that, salt water penetrates further upstream during flood tide (0.5 km) compare to ebb tide (0.2 km). A similar trend has been noticed by [27] in the Wouri-Nkam estuary indicating the positive nature of the horizontal salinity gradient of these estuaries.…”

“…The vertical gradient of both variables increased from surface to bottom and the longitudinal variation, revealed a decreased from the estuary mouth to upstream riverine end. The vertical and axial trend in TDS and conductivity could be due by the salt gradient produce during the intrusion of marine water [27].…”