[ Évolutions hydro-pluviométriques et exposition des zones urbaines aux inondations dans le bassin versant du N’zo: Cas des villes de Man, Guiglo et Bangolo (Côte d’Ivoire) ]
Koffi Daniel Kouassi1, Della André Alla2, and Kouadio Christophe N’Da3
1 Institut de Géographie Tropicale, Université Felix Houphouet Boigny, Abidjan, Côte d’Ivoire
2 Institut de Géographie Tropicale, Université Felix Houphouet Boigny, Abidjan, Côte d'Ivoire
3 Institut de Géographie Tropicale, Université Felix Houphouet Boigny, Abidjan, Côte d’Ivoire
Original language: French
Copyright © 2026 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
The urban areas of the N’zo watershed, in western Côte d’Ivoire, face recurring floods that exacerbate the vulnerability of the households exposed to them. The objective of this study is therefore to analyze the hydro-pluviometric dynamics in this basin in order to understand the recurrence of flooding in the urban areas of Man, Guiglo, and Bangolo. The study of hydro-pluviometric characteristics is therefore essential to understandingthe origins of this hydrological risk in these urban areas. To this end, statistical analyses have highlighted changes in precipitation as well as in the hydrological regime. Concurrently, the use of geographic information systems (GIS) has enabled the identification and spatialization of areas exposed to flooding. The results reveal annual and seasonal fluctuations in precipitation and runoff, with a high concentration during the period from July to October. This period is there fore particularly prone to the occurrence of high water levels and flooding. Furthermore, the study reveals that 28.67% of the urban area of Man is at risk of flooding. In Guiglo and Bangolo, the areas exposed to this natural hazard account for 49.88% and 36.63% of these urban areas, respectively. In this context, urban populations are exposed to this hydrological risk and are becoming increasingly vulnerable due to its recurrence.
Author Keywords: watershed, flooding, exposure, recurrence, urban area.
Koffi Daniel Kouassi1, Della André Alla2, and Kouadio Christophe N’Da3
1 Institut de Géographie Tropicale, Université Felix Houphouet Boigny, Abidjan, Côte d’Ivoire
2 Institut de Géographie Tropicale, Université Felix Houphouet Boigny, Abidjan, Côte d'Ivoire
3 Institut de Géographie Tropicale, Université Felix Houphouet Boigny, Abidjan, Côte d’Ivoire
Original language: French
Copyright © 2026 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
The urban areas of the N’zo watershed, in western Côte d’Ivoire, face recurring floods that exacerbate the vulnerability of the households exposed to them. The objective of this study is therefore to analyze the hydro-pluviometric dynamics in this basin in order to understand the recurrence of flooding in the urban areas of Man, Guiglo, and Bangolo. The study of hydro-pluviometric characteristics is therefore essential to understandingthe origins of this hydrological risk in these urban areas. To this end, statistical analyses have highlighted changes in precipitation as well as in the hydrological regime. Concurrently, the use of geographic information systems (GIS) has enabled the identification and spatialization of areas exposed to flooding. The results reveal annual and seasonal fluctuations in precipitation and runoff, with a high concentration during the period from July to October. This period is there fore particularly prone to the occurrence of high water levels and flooding. Furthermore, the study reveals that 28.67% of the urban area of Man is at risk of flooding. In Guiglo and Bangolo, the areas exposed to this natural hazard account for 49.88% and 36.63% of these urban areas, respectively. In this context, urban populations are exposed to this hydrological risk and are becoming increasingly vulnerable due to its recurrence.
Author Keywords: watershed, flooding, exposure, recurrence, urban area.
Abstract: (french)
Les zones urbaines du bassin versant du N’zo, dans l’Ouest de la Côte d’Ivoire, font face à une récurrence des inondations exacerbant la vulnérabilité des ménages qui y sont exposés. La présente étude a donc pour objectif d’analyser les dynamiques hydro-pluviométriques dans ce bassin afin de comprendre la récurrence des inondations dans les zones urbaines de Man, Guiglo et Bangolo. L’étude des caractéristiques hydro-pluviométriques est donc essentielle pour comprendre le la genèse de ce risque hydrologique dans ces territoires urbains. A cet effet, les analyses statistiques ont permis de mettre en évidence l’évolution des précipitations ainsi que celle du régime hydrologique. Parallèlement, l’utilisation des systèmes d’information géographique (SIG) a permis d’identifier et spatialiser les zones exposées aux inondations. Les résultats révèlent une fluctuation annuelle et saisonnière des précipitations et des débits, avec une forte concentration sur la période de juillet à octobre. Cette période s’avère donc particulièrement sensible à l’apparition des crues et des inondations. Par ailleurs, l’étude révèle que 28,67% de l’espace urbain de Man est exposé aux inondations. A Guiglo et Bangolo, les espaces exposés à ce risque naturel représentent respectivement 49,88% et 36,63 % de ces territoires urbains. Dans ce contexte, les populations urbaines sont exposées à ce risque hydrologique et deviennent de plus en plus vulnérables, en raison de sa récurrence.
Author Keywords: bassin versant, zone urbaine, inondation, exposition, récurrence.
