BackgroundThe dynamics of mosquito populations depends on availability of suitable surface water for oviposition. It is well known that suitable management of mosquito larval habitats in the sub-Saharan countries, particularly during droughts, could help to suppress vector densities and malaria transmission. We conducted a field survey to investigate the spatial and seasonal distribution of mosquito larval habitats and identify drought-refugia for anopheline larvae.MethodsA GIS approach was used to identify, geo-reference and follow up longitudinally from May 2012 to May 2013, all mosquito breeding sites in two rural sites (Yondarou and Thui), one urban (Kossarou), and one peri-urban (Pèdè) site at Kandi, a municipality in northeastern Benin. In Kandi, droughts are excessive with no rain for nearly six months and a lot of sunshine. A comprehensive record of mosquito larval habitats was conducted periodically in all sites for the identification of drought-refugia of anopheline larval stages. With geospatialisation data, seasonal larval distribution maps were generated for each study site with the software ArcGIS version 10.2.ResultsOverall, 187 mosquito breeding sites were identified of which 29.95% were recorded during drought. In rural, peri-urban and urban sites, most of the drought-refugia of anopheline larvae were domestic in nature (61.54%). Moreover, in rural settings, anopheline larvae were also sampled in cisterns and wells (25% of larval habitats sampled during drought in Yondarou and 20% in Thui). The mapping showed a significant decrease in the spatial distribution of mosquito larval habitats in rural, peri-urban and urban sites during drought, except in Yondarou (rural) where the aridity did not seem to influence the distribution of larval habitats.ConclusionOur data showed that the main drought-refugia of anopheline larvae were of a domestic nature as well as wells and cisterns. A suitable management of mosquito larvae in sub-Saharan countries, particularly during droughts, should target such larval habitats for a meaningful impact on the dynamics of mosquito populations and malaria transmission.

Résumé-Ces dernières décennies, l'exploitation des

La maîtrise de l'eau à des fins agricoles constitue un enjeu de taille dans les pays comme le Bénin où les besoins alimentaires sont en nette progression dans un contexte d'incertitudes climatiques. La présente recherche vise à caractériser les systèmes de production sur les aménagements hydro-agricoles dans le doublet Dangbo-Adjohoun situé dans la basse vallée de l'Ouémé. Les enquêtes de terrain ont été conduites dans huit (8) arrondissements (Késsounou, Houédomey, Gbéko, Zounguè, Gangban, Kodé, Démè et Azowlissè) auprès de 254 exploitants des sites d'aménagement hydro-agricole. Les informations qualitatives et quantitatives ont été recueillies par un questionnaire élaboré à cet effet. Le traitement des données a été fait par le test de Kruskal-Wallis pour tester la différence significative ou non entre les superficies emblavées sous les différents modes de faire valoir. Ainsi, l'analyse factorielle des correspondances simples a été utilisée pour décrire la spécificité au sein des arrondissements au regard des classes de superficie d'une part et des modes de faire valoir d'autre part. Le test d'homogénéité a permis de déterminer la tendance des systèmes de production. Les résultats d'analyse ont révélé l'existence de quatre (4) types de systèmes de production : le système de production pluviale, les systèmes de production irriguée, les systèmes de production des cultures de décrue et les systèmes de production de la pêche continentale. Pour cette recherche, le système de production pluviale qui se pratique sur le plateau n'a pas été pris en compte. Par ailleurs, les superficies aménagées varient d'un arrondissement à un autre en fonction des modes d'accès à la terre. Ainsi, l'héritage à la superficie moyenne la plus élevée, 5.78 ha suivi de propriétés collectives 1.64 ha, l'achat et l'emprunt ont respectivement les plus faibles superficies, 0.98 et 0.75 ha. Cette étude a montré les systèmes de production qui contribuent au développement des aménagements hydro-agricoles dans la plaine inondable.

Perceptions locales de la manifestation des changements climatiques et mesures d'adaptation dans la gestion de la fertilité des sols dans la Commune de Banikoara au Nord-Bénin 7418 Perceptions locales de la manifestation des changements climatiques et mesures d'adaptation dans la gestion de la fertilité des sols dans la Commune de Banikoara au Nord-Bénin

In the south of Oti catchment in Benin, the agricultural development of the lowlands for rice and vegetable cultivation, guarantees a large part of food resources. It also serves as an important source of financial income to agricultural households. This paper focuses on understanding the geographical foundations of this kind of agricultural production in the study area. Surveys of 207 farm households and the statistical processing of climatic, demographic, agricultural and socio-economic data have made it possible to highlight the natural and human factors of farm occupation and the use of these lowland agro-ecosystems. The results obtained revealed that the population of the south of Oti catchment has almost doubly increased between 1992 and 2013. It will increase four times in 2050 by creating the need to have excess food. In addition to this situation, climatic parameters fluctuation, plateau land qualitative tiredness, and major constraints of traditional agriculture were added. Henceforth, these are factors, in addition to the richness of the lowlands and water availability for a long period, which have helped in motivating the population of farmers. About 2000 ha of lowlands were reclaimed by irrigation schemes between 1982 and 2015 in this area. This was possible with the help of technical structures and agricultural development organizations.