Suivi des Paramètres Physico-Chimiques des Eaux Souterraines du Bassin de l’Alima, affluent du Fleuve Congo : Campagnes de Grande Saison Sèche 2021 et 2022 dans les Districts d’Oyo, Tchikapika et Boundji, République du Congo

Noida Janesia Lebela Mouakoumbat; Chesther Gatsé Ebotehouna; Urbain Gampio Mbilou

doi:10.19044/esj.2025.v21n18p96

Noida Janesia Lebela Mouakoumbat Doctorante, École nationale polytechnique, Université Marien Ngouabi, Brazzaville, Congo
Chesther Gatsé Ebotehouna Docteur, Ecole Normale Supérieure, Université Marien Ngouabi, Brazzaville, Congo
Urbain Gampio Mbilou Professeur Titulaire CAMES, Unité de Recherche d’hydrologie et hydrogéologie, Département de géologie, Faculté des Sciences et Techniques, Université Marien Ngouabi, Brazzaville, Congo

DOI: https://doi.org/10.19044/esj.2025.v21n18p96

Keywords: Eaux souterraines, physico-chimiques, qualité d’eau, saison sèche, bassin versant de l’Alima

Abstract

Cette étude, menée pendant les grandes saisons sèches de 2021 et 2022, a évalué la qualité hydrogéochimique des eaux souterraines des districts d'Oyo, Tchikapika et Boundji, situés dans le bassin versant de l'Alima. L'objectif était de déterminer leur aptitude à la consommation humaine et à l'irrigation. Des échantillons ont été prélevés sur 26 ouvrages en 2021 et 34 en 2022 (sources aménagées, puits et forages). Les analyses, réalisées au laboratoire de La Congolaise des Eaux (LCDE), ont porté sur des paramètres physiques (pH, température, conductivité, TDS) et chimiques (cations et anions). Les résultats globaux indiquent que les eaux respectent les normes de l'Organisation Mondiale de la Santé (OMS) pour la potabilité. La composition chimique est principalement dominée par les ions Ca²⁺, Na⁺, HCO₃⁻ et Cl⁻. Des variations ont été observées entre les années, avec des faciès bicarbonaté calcique et magnésien en 2021, et chloruré, sulfaté calcique et magnésien en 2022. L'influence des précipitations et de l'altération des silicates sur la chimie des eaux a été notée. Malgré une qualité chimique satisfaisante, l'étude souligne la persistance d'une acidité, une faible minéralisation et un potentiel de corrosion des infrastructures. Ces éléments, ainsi que les risques microbiologiques, nécessitent une surveillance continue pour prévenir d'éventuels risques sanitaires. Selon les critères de Wilcox, ces eaux sont jugées excellentes à bonnes pour l'irrigation. Cependant, un suivi microbiologique rigoureux est recommandé en raison de l'acidité et des risques de contamination. Ces conclusions sont cruciales pour l'élaboration de politiques de gestion de l'eau, visant à garantir la potabilité et la santé publique dans ces régions. Un suivi régulier et des interventions ciblées sont essentiels.

This study, conducted during the major dry seasons of 2021 and 2022, assessed the hydrogeochemical quality of groundwater in the Oyo, Tchikapika, and Boundji districts, located within the Alima watershed. The aim was to determine their suitability for human consumption and irrigation. Samples were collected from 26 water points in 2021 and 34 in 2022 (developed springs, wells, and boreholes). Analyses, performed at La Congolaise des Eaux (LCDE) laboratory, focused on physical parameters (pH, temperature, conductivity, TDS) and chemical parameters (cations and anions). Overall results indicate that the waters comply with World Health Organization (WHO) standards for potability. The chemical composition is primarily dominated by Ca²⁺, Na⁺, HCO₃⁻, and Cl⁻ ions. Variations were observed between years, with calcium and magnesium bicarbonate facies in 2021 and calcium and magnesium chloride-sulfate facies in 2022. The influence of precipitation and silicate weathering on water chemistry was noted. Despite satisfactory chemical quality, the study highlights persistent acidity, low mineralization, and potential for infrastructure corrosion. These factors, along with microbiological risks, necessitate continuous monitoring to prevent potential health hazards. According to Wilcox's criteria, these waters are considered excellent to good for irrigation. However, strict microbiological monitoring is recommended due to acidity and contamination risks. These conclusions are crucial for developing water management policies aimed at ensuring potability and public health in these regions. Regular monitoring and targeted interventions are essential.

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References

1. Adams, S., Titus, R., Pietersen, K., Tredoux G., & Harris, C. (2001). Hydrochemical characteristics of aquifers near Sutherland in the Western Karoo, South Africa: Journal of hydrology, Vol. 241, Issues 1-2, pp. 91-103.
2. Akil, A., Hassan, T., Lahcen, B., & Abderrahim, L. (2014). Etude de la qualité physico-chimique et contamination métallique des eaux de surface du bassin versant de Guigou, Maroc: European Scientific Journal, Vol. 10, Issues 23.
3. Ambarref, M., Saadia, A., Bernoussi, A., & Haddouchi, B. (2007). Mapping vulnerability to groundwater pollution: application to the Gharb plain (Morocco): Rev Sci Eau, Vol. 20, Issues 2, pp. 185-199.
4. Ansari, J. A., Umar, R. (2019). Evaluation of hydrogeochemical characteristics and groundwater quality in the quaternary aquifers of Unnao District, Uttar Pradesh, India: HydroResearch, Vol. 1, pp. 36-47.
5. Appelo, C., & Postma D. (1996). Geochemistry, groundwater and pollution (3 rd corrected print): Balkema, Rotterdam, Vol. 536.
6. Bocquier, G (1960). Note concernant les travaux pédologiques dans la cuvette congolaise, Republique du Congo.
7. Bouteldjaoui, F., & Taupin JD. (2023). Assessment of some bottled natural mineral waters and spring waters in Algeria using multivariate statistical analysis, hydrogeochemical approaches and water quality index (WQI): International Journal of Environmental Analytical Chemistry, pp. 1-25.
8. BRGM (Bureau de Recherches Geologiques et Minieres) (1982). Notice explicative de la carte de planification des ressources en eau du Gabon et du Congo, Serie hydrogéologie de Comité Interafricain d’Etudes Hydrauliques (CIEH), 116pp, Ouagadougou. Burkinafasso.
9. Brindha, K., Pavelic, P., Sotoukee, T., Douangsavanh, S., & Elango L. (2017). Geochemical characteristics and groundwater quality in the Vientiane plain, Laos: Exposure and Health, Vol. 9, Issues. 2, pp. 89-104.
10. Chadha, D (1999). A proposed new diagram for geochemical classification of natural waters and interpretation of chemical data: Hydrogeology journal, v. 7, p. 431-439.
11. Chen, W., Zhang, Y., Shi, W., Cui, Y., Zhang, Q., Shi, Y., & Liang, Z. (2021). Analysis of Hydrogeochemical Characteristics and Origins of Chromium Contamination in Groundwater at a Site in Xinxiang City, Henan Province: Applied Sciences, Vol. 11, Issues. 24, pp. 11683.
12. Ganiyu, S., Badmus, B., Olurin, O., & Ojekunle Z. (2018). Evaluation of seasonal variation of water quality using multivariate statistical analysis and irrigation parameter indices in Ajakanga area, Ibadan, Nigeria: Applied water science, Vol. 8, pp. 1-15.
13. Gibbs, RJ (1970). Mechanisms controlling world water chemistry: Science, Vol. 170, Issues. 3962, pp. 1088-1090.
14. Goula, BTA., Savane, I., Konan, B., Fadika V., & Kouadio GB. (2006). Impact de la variabilité climatique sur les ressources hydriques des bassins de N’Zo et N’Zi en Côte d’Ivoire (Afrique tropicale humide): VertigO-la revue électronique en sciences de l'environnement, Vol. 7, Issues. 1.
15. Husain, MS., Umar, R., & Ahmad S. (2020). A comparative study of springs and groundwater chemistry of Beas and Parbati valley, Kullu District, Himachal Pradesh, India: HydroResearch, Vol. 3, pp. 32-47.
16. INS (Institut National de la Statistique), (2020). Annuaire statistique du departement de la Cuvette 2018.
17. Itoua, TR., Mahoungou, GI., Maloba-Makanga, JD., Maniaka, FW., Samba-Kimbata, MJ. (2017). Evolution Decenale Des Regimes Pluviometriques Au Nord-Congo (République du Congo) de 1932 à 2011. Revues-ufhb-ci.org.
18. Jain, C., Bandyopadhyay, A., & Bhadra A. (2010). Assessment of ground water quality for drinking purpose, District Nainital, Uttarakhand, India: Environmental monitoring and assessment, Vol. 166, pp. 663-676.
19. Khan, R., & Jhariya D. (2018). Hydrogeochemistry and groundwater quality assessment for drinking and irrigation purpose of Raipur City, Chhattisgarh: Journal of the Geological Society of India, Vol. 91, pp. 475-482.
20. Krishna Kumar, S., Logeshkumaran, A., Magesh, N., Godson, PS., & Chandrasekar N. (2015). Hydro-geochemistry and application of water quality index (WQI) for groundwater quality assessment, Anna Nagar, part of Chennai City, Tamil Nadu, India: Applied Water Science, Vol. 5, pp. 335-343.
21. Kumar, L., Deitch, MJ., Tunio, IA., Kumar A., Memon SA., Williams L., Tagar U., Kumari R., & Basheer S. (2022). Assessment of physicochemical parameters in groundwater quality of desert area (Tharparkar) of Pakistan: Case Studies in Chemical and Environmental Engineering, Vol. 6, pp. 100232.
22. Kumar, PS (2014). Evolution of groundwater chemistry in and around Vaniyambadi industrial area: differentiating the natural and anthropogenic sources of contamination: Geochemistry, Vol. 74, Issues 4, pp. 641-651.
23. Laraque, A., & Olivry, J. (1998). Two hydrological systems close but opposite of the Congo-Zaire: the Congolese basin and Teke plateaux, in Proceedings International Conference on tropical climatology, meteorology and hydrology in memoriam Franz Bultot, Bruxelles (Belgium), pp. 22-24 May 1996, 1998, Royal Meteorological Institute of Belgium; Royal Academy of Overseas Sciences.
24. Li, P., Wu, J., Tian, R., He, S., He X., Xue, C., & Zhang K. (2018). Geochemistry, hydraulic connectivity and quality appraisal of multilayered groundwater in the Hongdunzi Coal Mine, Northwest China: Mine Water and the Environment, Vol. 37, Issues 2, pp. 222-237.
25. Lyu, M., Pang, Z., Yin, L., Zhang, J., Huang, T., Yang, S., Li Z., Wang, X., & Gulbostan, T. (2019). The control of groundwater flow systems and geochemical processes on groundwater chemistry: a case study in Wushenzhao Basin, NW China: Water, Vol. 11, Issues. 4, pp. 790.
26. Makhoukh, M., Sbaa, M., Berrahou, A., & Van Clooster, M. (2011). Contribution a l’étude physico-chimique des eaux superficielles de l’Oued Moulouya (Maroc oriental): LARHYSS Journal P-ISSN 1112-3680/E-ISSN. , Issues 9, pp. 2521-9782.
27. Mgbenu, CN., & Egbueri J.C. (2019). The hydrogeochemical signatures, quality indices and health risk assessment of water resources in Umunya district, southeast Nigeria: Applied water science, Vol. 9, Issues 1, p. 22.
28. Mondal, N., Singh, V., Saxena, V., & Singh, V. (2011). Assessment of seawater impact using major hydrochemical ions: a case study from Sadras, Tamilnadu, India: Environmental monitoring and assessment, Vol. 177, pp. 315-335.
29. Murhula, EM., Kutangila, SM., Birhenjira, EM., & Muyisa, SK. (2019). Hydrogéochimie et susceptibilité à la contamination des eaux souterraines dans le secteur de Panzi, ville de Bukavu, RD Congo: Geo-Eco-Trop, Vol. 43, Issues 1, pp. 197-209.
30. Ojekunle, ZO., Adeyemi, AA., Taiwo AM., Ganiyu, SA., & Balogun MA., (2020). Assessment of physicochemical characteristics of groundwater within selected industrial areas in Ogun State, Nigeria: Environmental pollutants and bioavailability, Vol. 32, Issues 1, pp. 100-113.
31. OMS, World Health Organization (W.H.O), (2019). Guidelines for drinking-water quality, Fourth edition. 2011. ISBN 978 92 4 154815 1 [cited 2019 Nov 24]. Available from: http://www.who.int.
32. Ravikumar, P., Somashekar, R., & Angami, M. (2011). Hydrochemistry and evaluation of groundwater suitability for irrigation and drinking purposes in the Markandeya River basin, Belgaum District, Karnataka State, India: Environmental monitoring and assessment, Vol. 173, pp. 459-487.
33. Roy, A., Keesari, T., Mohokar, H., Pant, D., Sinha, UK., & Mendhekar G. (2020). Geochemical evolution of groundwater in hard-rock aquifers of South India using statistical and modelling techniques: Hydrological Sciences Journal, Vol. 65, Issues 6, pp. 951-968.
34. Sajil Kumar, P., Delson, PD., & James, E. (2014). Evaluation of groundwater chemistry in Vaniyambadi industrial area with special reference on irrigation utility: National Academy Science Letters, Vol. 37, pp. 493-502.
35. Sajil Kumar, P., Mohanan, AA., & Ekanthalu, VS. (2020). Hydrogeochemical analysis of Groundwater in Thanjavur district, Tamil Nadu; Influences of Geological settings and land use pattern: Geology, Ecology, and Landscapes, Vol. 4, Issues 4, pp. 306-317.
36. Sandao, I., Babaye, MSA., Ousmane, B., & Michelot, JL. (2018). Apports des isotopes naturels de l’eau ā la caractérisation des mécanismes de recharge des aquifčres du bassin de la Korama, Région de Zinder, Niger: International Journal of Biological and Chemical Sciences, Vol. 12, Issues 4, pp. 1931-1954.
37. Sawyer, C., & Mccarthy, P. (1967). Chemical and sanitary engineering, McGraw-Hill, New York.
38. Selvakumar S., Chandrasekar N., Kumar G. (2017). Hydrogeochemical characteristics and groundwater contamination in the rapid urban development areas of Coimbatore, India: Water Resources and Industry, Vol. 17, pp. 26-33.
39. Sethy, SN., Syed, TH., Kumar, A., & Sinha, D. (2016). Hydrogeochemical characterization and quality assessment of groundwater in parts of Southern Gangetic Plain: Environmental Earth Sciences, Vol. 75, pp. 1-15.
40. Singh, A., Patel, AK., Ramanathan, A., & Kumar M. (2020). Climatic influences on arsenic health risk in the metamorphic precambrian deposits of Sri Lanka: a re-analysis-based critical review: Journal of Climate Change, Vol. 6, Issues 1, pp. 15-24.
41. Souleymane, IMS., Babaye, MSA., Alhassane, I., & Boureima, O. (2020). Caractérisations hydrogéochimiques et qualités des eaux de la nappe phréatique du haut bassin versant de la Korama, commune de Droum/région de Zinder (Niger/Afrique de l’Ouest): International Journal of Biological and Chemical Sciences, Vol. 14, Issues 5, pp. 1862-1877.
42. U.S Salinity Laboratory Staff. (1954). Diagnosis and improvement of saline and alkali soils. US Department of Agriculture.
43. Subramani, T., Elango, L., & Damodarasamy, S. (2005). Groundwater quality and its suitability for drinking and agricultural use in Chithar River Basin, Tamil Nadu, India: Environmental Geology, Vol. 47, pp. 1099-1110.
44. Thierrin, J., Steffen, P., Cornaz, S., Vuataz, F.-D., Balderer, W., & Looser, M. (2003). Echantillonnage des eaux souterraines: Guide pratique: Publications de l’Office fédéral de l’environnement, des forêts et du paysage (OFEFP), pp. 1-83.
45. Vasanthavigar, M., Srinivasamoorthy, K., & Prasanna, M. (2012). Evaluation of groundwater suitability for domestic, irrigational, and industrial purposes: a case study from Thirumanimuttar river basin, Tamilnadu, India: Environmental Monitoring and Assessment, Vol. 184, pp. 405-420.
46. Wilcox, L., Blair, GY., & Bower, C. (1954). Effect of bicarbonate on suitability of water for irrigation: Soil Science, Vol. 77, Issues 4, pp. 259-266.
47. Wilcox, LV. (1948). The quality of water for irrigation use.