With the increasing frequency of floods in recent decades, particularly in West Africa, many regions have faced unusual and recurrent flooding events. Communities in flood-prone areas experience heightened insecurity, loss of property, and, in some cases, serious injuries or fatalities. Consequently, flood risk assessment and mitigation have become essential. This comparative study between Niamey and Lokoja employs Geographic Information Systems (GIS) and the Analytical Hierarchy Process (AHP) to delineate flood susceptibility, vulnerability, and risk zones. The study utilized a comprehensive range of thematic layers, with weight percentages assigned to each parameter as follows: 29% for elevation, 24% for slope, 15% for the Topographic Wetness Index (TWI), 9% for drainage density, 9% for distance from rivers, 4% for both precipitation and the Normalized Difference Water Index (NDWI), and 2% each for the Normalized Difference Vegetation Index (NDVI) and soil type. To validate these weightings, a consistency ratio was calculated, ensuring it remained below 10%. The findings reveal that 32% of the Niamey study area is at risk of flooding, compared to approximately 15% in Lokoja. The results highlight a very high flood potential, particularly in areas near the Niger River, with this potential decreasing as elevation increases. Given the current prevalence of extreme weather events in West Africa, it is crucial to employ effective tools to mitigate their adverse impacts. This research will assist decision-makers in quantifying the spatial vulnerability of flood-prone areas and developing effective flood risk assessment and mitigation strategies in the region.

This study was undertaken to obtain direct and useful data that support biodiversity awareness and management in two cities of Niger. 800 questionnaires were administrated to the populations of Niamey and Maradi. The results show that 99% of respondents are aware of the importance of biodiversity in urban areas. They assign multiple roles to it; however, climatic and managerial reasons explain why plants are most preferred to animals in these cities. Furthermore, shade and fruits are the criteria for plant species selection, and that explains the abundance of Azadirachta indica A. Juss. and Mangifera indica L. Even though plants are preferred to animals in houses, 47% of the respondents practice animal husbandry. Most of the animals are left wandering with risks of destruction of green areas, road unsafety, and zoonotic contamination. The results of this study also showed the ignorance of 55% of the respondents about the presence of wildlife in urban areas. The proliferation of cockroaches and rats could be an indication of insanitary conditions that are faced in some areas of the cities as mentioned by 81% of the respondents. This study shows the importance of local knowledge in the identification process of urban problems.

In Tahoua, access to safe water, adequate sanitation, and effective wastewater management remains a major concern. These conditions may increase exposure to contaminated water and environments, particularly among children under five years of age, who are more susceptible to waterborne diseases. This study aimed to analyze waterborne disease morbidity among children under five years of age monitored at five Integrated Health Centers (IHCs) in Tahoua. We collected data through a survey of 360 households and a review of health records from January to August 2024. The results show that 78.33% of households dump wastewater on the street, exposing the population to serious sanitary risks. The most frequently reported diseases were malaria (41.94%) and diarrhea (36.11%), with children under five years of age accounting for 75% of reported cases. The spatiotemporal analysis revealed a concentration of malaria cases in the northern and western areas and of diarrhea cases in the southern and southwestern areas, with a morbidity peak during the rainy season (July–August). Statistical analysis confirmed a significant variation in malaria cases among months (p = 0.025), while Pearson correlations showed strong relationships between wastewater dumping on the street and diarrhea (r = 0.829) and dysentery (r = 0.967). Principal component analysis highlighted an association between informal wastewater disposal practices and waterborne diseases, whereas the use of sumps appeared to be a protective factor. These findings underline the need to strengthen sanitation infrastructure, community awareness, and epidemiological monitoring, particularly in the most exposed areas.