In situ Physicochemical Characterisation of Spring Waters in Crystalline Basement Environments: A Comparative Analysis with Surface Waters and Deep Groundwater in Daloa, Côte d’Ivoire

Kouassi Jean-Michel Kouassi — 2026-08-14

Maintaining the availability of groundwater, in terms of both quantity and quality, is essential to guarantee access to drinking water in many countries around the world, particularly in the bedrock regions of West Africa. In most crystalline bedrock areas of West Africa, due to the poor quality of surface water, people are increasingly turning to groundwater, particularly water from springs. In the municipality of Daloa (central-western Côte d’Ivoire), spring water is increasingly being used by all social groups to meet their drinking water needs. This study aims to understand the interactions between different water resources using physicochemical parameters in order to better guide policies for the management of springs in the localities of Daloa, which are under increasing pressure from the local population. This study is based on the statistical analysis of a dataset collected during a campaign to measure the physicochemical parameters of water in the Tétégbeu River catchment area in Daloa. Data collection was carried out according to a rigorous protocol, with quality control checks performed on each parameter measured. The physicochemical parameters, notably temperature, pH, electrical conductivity and redox potential, were measured in situ using a multi-parameter analyser. The results show that the spring waters generally exhibit physicochemical characteristics intermediate between those of surface water and deep aquifers. However, several parameters, notably temperature, pH, electrical conductivity and redox potential, indicate a closer resemblance to water from deep aquifers extracted via boreholes. This similarity suggests that deep aquifers contribute to the existence of the springs, with a limited but not negligible contribution from watercourses (rivers). Thus, the springs appear to be transitional waters that emerge from shallow aquifers with a contribution from deep aquifers, but which may be locally influenced by inflows from rivers. This dual influence gives the springs a distinctive physicochemical signature, reflecting both the dynamics of underground flow and interactions with the surface environment. These results contribute to a better understanding of the hydrogeological behaviour of spring waters in a crystalline basement context and provide an essential basis for guiding spring management policies, particularly in the face of increasing pressure from human activities.

Physiological and Multivariate Characterization of Chitosan-Indiced Drought Tolerance in Groundnut (Arachis hypogaea L.) Seedlings

Srijan Samanta — 2026-08-19

Early-stage drought stress severely limits seedling establishment in groundnut (Arachis hypogaea L.), necessitating effective biostimulant-based approaches to enhance drought tolerance. This study aimed to identify the optimum foliar concentration of chitosan for improving seedling growth and physiological performance under contrasting moisture regimes using integrated multivariate analyses. A factorial completely randomised design with three replications was employed, comprising two moisture regimes (well-watered and water-stressed) and six chitosan concentrations (0, 100, 200, 300, 400, and 500 ppm). Chitosan was applied as a foliar spray at 15 days after sowing, and growth, biomass, relative leaf water content (RLWC), membrane stability index (MSI), and cellular metabolic activity were evaluated after 15 days. Chitosan significantly enhanced all measured traits under both moisture conditions, with responses increasing up to 300 ppm before declining at higher concentrations. The 300 ppm treatment produced the highest shoot length (27.01 cm), root length (19.55 cm), fresh biomass (3.32 g seedling⁻¹), RLWC (84.83%), MSI (83.00%), and cellular metabolic activity (2.14 A₄₈₅ g⁻¹ FW). Pearson's correlation analysis revealed strong positive associations among growth, biomass accumulation, water status, membrane stability, and cellular metabolic activity, while principal component analysis explained 87.2% of the total variation. The Composite Performance Index (CPI), integrated with quadratic regression, predicted optimum chitosan concentrations of approximately 322 ppm under water stress and 300 ppm under well-watered conditions. As both predicted optima closely corresponded to the tested 300 ppm treatment, this concentration was identified as the practical optimum. These findings demonstrate that foliar application of chitosan at 300 ppm effectively enhances seedling vigour and physiological resilience under both drought-stressed and well-watered conditions, providing a scientifically validated dose for future greenhouse and field evaluation.

Journal of Geography, Environment and Earth Science International

In situ Physicochemical Characterisation of Spring Waters in Crystalline Basement Environments: A Comparative Analysis with Surface Waters and Deep Groundwater in Daloa, Côte d’Ivoire

Physiological and Multivariate Characterization of Chitosan-Indiced Drought Tolerance in Groundnut (Arachis hypogaea L.) Seedlings