ANALYSE DES CONTRAINTES DE VIABILITE DE LA VEGETATION URBAINE : CAS DES ARBRES D’ALIGNEMENT DANS LA VILLE DE PORTO-NOVO AU BENIN

Many efforts have been made in recent decades to provide urban forestry a tool of conservation plantre sources and sustainable development of cities. In southern countries, these efforts are more focused on conventional reforestation and education without much considers the factors that determine the survival of the trees.This study on the Porto-Novo city in Bénin, is a better understanding of the viability of urban trees, including those planted by analyzing the constraints of the medium. Lands atimages were used to determine state changes in vegetation cover in 2003 and 2013 An inventory of forms of mutilation on the trees is associated with a survey of populations to link the urban practices and their causes on the viability of urban trees. For data processing, normalized vegetation index is calculated in ENVI5 and mapped in ArcGIS10. Chi Square test and correspondence analysisare performed under R. The results show a decline in the normal state and moderate vegetation and an increase in stress states and mineral areas. Depending on the population, it is the anthropogenic activities (P= 0.001) and planning conditions (P= 0.01), which are currently the factors significant constraint strees. The consequences are biologically and landscape esthetically. The inclusion of such information is necessary for a better future of urban forestry in the city

Analyse Des Déterminants Du Choléra Dans La Ville De Djougou Au Bénin

The propagation and the persistence of the infectious diseases are the facts which is recurring and disturb the development process in the African countries. This’s the case of the cholera which, despite efforts of eradication, persists and compromises the socio-economic activities of the communities west-African. The town of Djougou in Benin is not out of this acute and dangerous intestinal affection for the survival of the populations. This study aims to identify and prioritize the risk factors basic of the cholera in order to suggest solutions to its eradication. The methodological approach used for this purpose is based on a casecontrol analytical approach. Several variables were used and the chi-square test assessed the degree of association between each disease and the occurrence of the disease. The got results reveal a significant link between the source of supply out of drink water and the cholera (p = 0.047), the water treatment before its consumption and the cholera (p = 0.03). In the same way, one notes a highly significant association between the contact with a choleraic patient and which has occurred of the cholera (p= 0.0001) and between the none observance of hand-washing to running water with soap and the cholera (p = 0.0001)

Spatial Diagnosis and Conceptualisation of Greening Plan of Seme-Podji, Benin (West Africa)

Conservation and sustainable management of natural resources are increasingly recommended in decentralized territories. The most effective approach for this process is the participation of local communities because their knowledge is valuable in policy implementation. The study aims to propose a sustainable management model of a territory based on the needs of communities in order to conserve the natural resources in the Sèmè-Podji municipality in Benin, West Africa. Local knowledge and community’s needs have been used in association with GIS technics to make a diagnosis of the territory and propose a land use map for the municipality. The spatial diagnosis revealed an anthropization of the land cover, with a predominance of agro-systems, built up areas, croplands and fallow which represent 80.03% of the total area of the municipality. The marshlands which mostly serve as a refugium and support biodiversity represent 5.42%. The proposed plan showed that 84.79% (p ˂ 0.001) of socio-professional needs are explained. Therefore, the proposed actions were related to the restoration of ecological continuity, creation of new green recreational spaces, the protection of marshlands, the management of natural protected areas and the creation of fuel wood tree plantations. The current information can contribute to a sustainable and inclusive landscape planning for such municipalities, like our study site at Sèmè-Podji in Benin

Diversité floristique des formations végétales urbaines au Sud du Bénin (Afrique de l’Ouest)

Trees in urban areas have become an essential element for sustainable environment. However, in some African cities, the emphasis is often not placed on this forest heritage. The present study carried out in the districts of Abomey-Calavi, Allada and Cotonou in southern Benin aimed to assess the diversity of trees in public and private green spaces for the improvement of the urban environment. The method of itinerant surveys was used to identify the plant species found in the alignment trees, the green public squares and the concessions of these cities. During the study, the dendrometric and geographical parameters of trees with dbh ? 15 cm were collected. The diversity index, biological types and phytogeographic affinity of the species were analyzed. The results showed a floristic richness composed of 61 plant species distributed in 56 genus and 30 families. Leguminosae (33.3%), Arecaceae (16.0 %), Combretaceae (10.0%) are the dominant families. Shannon's diversity index and Pielou's equitability index are respectively between 2.92 to 3.03 bits and 0.65 to 0.67 bits. Mesophanerophytes are also abundant (57.0%). The relative abundance of pantropical species over other phytogeographic types confirms the loss of local biodiversity in our urban environments. The present study constitutes an important awareness for the preservation of green spaces in these cities. Keywords: urban biodiversity, urban green space, biological types, phytogeographic types, BeninL’arbre en milieu urbain est devenu dorénavant un élément essentiel pour un environnement vivable et durable. Mais, dans certaines villes africaines, l'accent n'est souvent pas mis sur ce patrimoine forestier. La présente étude réalisée dans les villes d’Abomey-Calavi, Allada et Cotonou situées au Sud du Bénin a pour but d’évaluer la diversité des arbres dans les espaces verts publics et privés pour l’amélioration de l’environnement urbain. La méthode de relevés itinérants a permis de recenser les espèces végétales que comportent les arbres d’alignement, les places publiques végétalisées et les concessions de ces villes. Au cours de l’inventaire, les paramètres dendrométriques et géographiques des individus de dbh ? 15 cm ont été notés. Les indices de diversité, les types biologiques et l’affinité phytogéographique des espèces ont été analysés. Les résultats obtenus ont montré une richesse floristique composée de 61 espèces végétales réparties dans 56 genres et 30 familles. Les Leguminosae (33,3 %), les Arecaceae (16,0 %), les Combretaceae (10,0%) sont les familles dominantes. Les indices de diversité de Shannon et l’équitabilité de Piélou sont compris respectivement entre 2,92 à 3,03 bits et 0,65 à 0,67. On note par ailleurs une abondance des mésophanérophytes (57,0%). L’abondance relative des espèces pantropicales sur les autres types phytogéographiques confirme la perte de la biodiversité locale dans nos milieux urbains. La présente étude constitue une importante sensibilisation pour le maintien des espaces verts dans ces villes. Mots clés: biodiversité urbaine, espace vert urbain, types biologiques, types phytogéographiques, Béni

Mutations Spatiales Du Paysage Et Prospective Territoriale Dans Le Secteur Habité De La Commune De Karimama Au Nord Bénin

AbstractRemote sensing is very requested over last years for land-use and land cover monitoring at several spatial levels. ¶But beyond this stake, it plays a significant role in spatial planning while bringing answers to the environmental concerns. This study aims to analyze the landscape changes and to predict the future land-use changes in the inhabited sector of the of Karimama common, for a sustainable spatial planning. The methodological approach used is based on remote sensing technics, which allowed to make Landsat image processing of the years 1988;¶2003 and 2018 with Envi 5.3 software. ¶A predictive modeling was carried out starting from the extension "Land Change Modeler" available on IDRISI to generate the future probabilities of these changes. ¶The obtained results show that over the thirty last years, the landscape area has considerably changed. It ¶is is observed a crucial anthropization phenomenon caused by a conversion of the forest units into crop and fallow areas. ¶In addition, the inhabited sector of the commune is in full change, in particular the easily flooded zones of plain formerly occupied by the forest galleries and shrubby raised savannas, were transformed into marshy zones under the effect of the natural risks. ¶The prospective analysis carried out on the data shows that if no measurement of installation is taken, the two evoked tendencies will continue until 2033 and are likely to compromise the regional planning.¶Key words: Remote sensing; Spatial changes¶S; R¶S¶egional planning; ¶Karimama, Beni

Spatial Diagnosis and Conceptualisation of Greening Plan of Seme-Podji, Benin (West Africa)

Conservation and sustainable management of natural resources are increasingly recommended in decentralized territories. The most effective approach for this process is the participation of local communities because their knowledge is valuable in policy implementation. The study aims to propose a sustainable management model of a territory based on the needs of communities in order to conserve the natural resources in the Sèmè-Podji municipality in Benin, West Africa. Local knowledge and community’s needs have been used in association with GIS technics to make a diagnosis of the territory and propose a land use map for the municipality. The spatial diagnosis revealed an anthropization of the land cover, with a predominance of agro-systems, built up areas, croplands and fallow which represent 80.03% of the total area of the municipality. The marshlands which mostly serve as a refugium and support biodiversity represent 5.42%. The proposed plan showed that 84.79% (p ˂ 0.001) of socio-professional needs are explained. Therefore, the proposed actions were related to the restoration of ecological continuity, creation of new green recreational spaces, the protection of marshlands, the management of natural protected areas and the creation of fuel wood tree plantations. The current information can contribute to a sustainable and inclusive landscape planning for such municipalities, like our study site at Sèmè-Podji in Benin

Spatial Dynamics and Predictive Analysis of Vegetation Cover in the Ouémé River Delta in Benin (West Africa)

The vegetation cover of the Ouémé Delta constitutes a biodiversity hotspot for the wetlands in southern Benin. However, the overexploitation of natural resources in addition to the intensification of agricultural practices led to the degradation of the natural ecosystems in this region. The present work aims to reconstruct, using remote sensing, the spatial dynamics of land use in the Ouémé Delta in order to assess the recent changes and predict the trends in its vegetation cover. The methodology was based on remote sensing and GIS techniques. Altogether, this process helped us carry out the classification of Landsat images for a period of 30 years (stating year 1990, 2005, and 2020) via the Envi software. The spatial statistics resulting from this processing were combined using ArcGIS software to establish the transition matrices in order to monitor the conversion rates of the land cover classes obtained. Then, the prediction of the plant landscape by the year 2035 was performed using the “Land Change Modeler” extension available under IDRISI. The results showed seven (07) classes of occupation and land use. There were agglomerations, mosaics of fields and fallow land, water bodies, dense forests, gallery forests, swamp forests, and shrubby wooded savannahs. The observation of the vegetation cover over the period of 15 years from 1990 to 2005 showed a decrease from 71.55% to 63.42% in the surface area of the Ouémé Delta. A similar trend was noticed from 2005 to 2020 when it reached 55.19%, entailing a loss of 16.37% of the surface area of natural habitats in 30 years. The two drivers of such changes are the fertility of alluvial soils for agriculture along and urbanization. The predictive modeling developed for 2035 reveals a slight increase in the area of dense forests and shrubby wooded savannas, contrary to the lack of significant decrease in the area of gallery forests and swamp forests. This is key information that is expected to be useful to both policy and decision makers involved in the sustainable management and conservation of natural resources in the study area

Reconstitution spatiale et simulation des changements futurs de l'occupation du sol dans la Réserve de Biosphère de la basse vallée de l'Ouémé (RB-BVO) au Bénin

Le terrain d'étude, aux zones humides étendues, appartient au site Ramsar 1018 inscrit en 2000 et a été classé Réserve de Biosphère par l'UNESCO en 2020. La reconstitution de la dynamique spatio-temporelle de l'occupation du sol a permis d'analyser les mutations au fil du temps, puis de prédire les changements futurs dans une perspective de durabilité des initiatives de conservation. Les images Landsat des années 1990, 2005 et 2020 ont subi une classification supervisée à l'aide des techniques de la télédétection et du SIG. Les données issues de ce traitement ont été combinées pour établir les matrices de transition permettant d'apprécier les taux de conversion des différentes classes d'occupation du sol. Les changements futurs de l'occupation du sol à l'horizon 2035 ont été simulés en utilisant le modèle "Land Change Modeler".Les résultats obtenus indiquent qu'en 1990, le site était couvert à 70,9 % de formations végétales spontanées (savanes arbustives et arborées, forêts denses et galeries, formations de marécage). Leur part est tombée à 61,6 % en 2005, puis à 53,6 % en 2020, soit une perte de 24,4 % en valeur relative sur une période de 30 ans.Le scenario élaboré pour l'avenir prédit que les formations spontanées seront toujours légèrement dominantes (52,2 % de la superficie totale), alors que les plus grandes superficies resteront occupées à égalité par les formations de marécage et par les champs et jachères (24,4 %). Ces informations doivent cependant être considérées avec prudence.The study area, with its extensive wetlands, belongs to the Ramsar site 1018, which was inscribed in 2000 and was classified as a Biosphere Reserve by UNESCO in 2020. The reconstruction of the spatio-temporal dynamics of the land cover will enable the analysis of changes over time and the prediction of future changes in a perspective of sustainable conservation initiatives. Landsat images from 1990, 2005 and 2020 were subjected to supervised classification using remote sensing and GIS techniques. The resulting data were combined to establish transition matrices to assess the conversion rates of the different land use classes. Future land use changes up to 2035 were simulated using the Land Change Modeler.The results obtained indicate that in 1990, 70.9% of the site was covered by spontaneous vegetation formations (shrub and tree savannahs, dense and gallery forests, swamp formations). Their share fell to 61.6% in 2005 and to 53.6% in 2020, which represents a loss of 24.4% in relative terms over a 30-year period.The scenario developed for the future shows that spontaneous formations will still be slightly dominant (52.2% of the total area), while the largest areas will remain equally occupied by swamp formations and by fields and fallow land (24.4%). However, this information must be taken with caution.Translated with www.DeepL.com/Translator (free version

Reconstitution spatiale et simulation des changements futurs de l'occupation du sol dans la Réserve de Biosphère de la basse vallée de l'Ouémé (RB-BVO) au Bénin

The study area, with its extensive wetlands, belongs to the Ramsar site 1018, which was inscribed in 2000 and was classified as a Biosphere Reserve by UNESCO in 2020. The reconstruction of the spatio-temporal dynamics of the land cover will enable the analysis of changes over time and the prediction of future changes in a perspective of sustainable conservation initiatives. Landsat images from 1990, 2005 and 2020 were subjected to supervised classification using remote sensing and GIS techniques. The resulting data were combined to establish transition matrices to assess the conversion rates of the different land use classes. Future land use changes up to 2035 were simulated using the Land Change Modeler.The results obtained indicate that in 1990, 70.9% of the site was covered by spontaneous vegetation formations (shrub and tree savannahs, dense and gallery forests, swamp formations). Their share fell to 61.6% in 2005 and to 53.6% in 2020, which represents a loss of 24.4% in relative terms over a 30-year period.The scenario developed for the future shows that spontaneous formations will still be slightly dominant (52.2% of the total area), while the largest areas will remain equally occupied by swamp formations and by fields and fallow land (24.4%). However, this information must be taken with caution.Translated with www.DeepL.com/Translator (free version