- Mapping of the susceptibility to landslides in Bafoussam (Cameroon). Multi-criteria hierarchical analysis and Geographic Information Systemapproach
- Spatial changes and environmental degradation in the locality of Bétaré-Oya (East Cameroon).
- Mapping using multi-criteria hierarchical analysis of landslide risk areas in the Menoua watershed (West Cameroon).
- Landslide Geophysical Risk Modeling Using Multi-Tiered Geospatial Data for Southern California.
- Land use dynamics in Dizangue (Cameroon) from 1975 to 2019 and impact on the Ossa lake wildlife reserve.
- Contribution of the Geographic Information System (GIS) in hydroagricultural development in East Batha in Chad.
- Contribution of GIS in monitoring of reforestation activities in forest School of NFS of Mbalmayo (Cameroon).
- An appraisal of wetland ecosystems of the Bamenda City in Cameroon : characteristics and services.
- Peasant perception of the impacts of nutgrass cultivation (Cyperus esculentus L.) on soil degradation in Aguié department (Niger).
- Anthropogenic pressures and degradation of surface water in San-Pedro (Côte-d'Ivoire).
- Oil palm production: a panacea for rural development in Mamfe sub division in the south west region (Cameroon).
- Women's organizations and microfinance facing the challenges of empowerment and local development : the case of EXPRESS MIA in N’djamena.
Mapping of the susceptibility to landslides in Bafoussam (Cameroon). Multi-criteria hierarchical analysis and Geographic Information Systemapproach
TANGMOUO TSOATA Francis (1), YEMMAFOUO Aristide (2), NGOUANET Chrétien (3)
1) Ingénieur SIG appliqué à la gestion des risques et l’aménagement urbain, Labo.Géomatique, Université de Dschang (Cameroun)
2) Professeur, Géographie urbaine, Université de Dschang (Cameroun)
3) Maître de Recherche, Institut National de Cartographie, Yaoundé (Cameroun)
Abstract. Urban growth in Southern cities strengthens the mechanisms of production of natural risks. Bafoussam has seen its population double in the space of 15 years, from 293,000 in 2005 to 600,000 inhabitants in 2020. This spectacular urban growth is above all anarchic and produces natural disasters like the deadly landslide of October 29, 2019, in the Gouache IV district. The level of susceptibility of sites exposed to landslides can be modelled by observing and representing predisposing factors such as soil morphology, land use, geology, climate and hydrology. This study aims to develop an approach to modelling the level of susceptibility to landslides in urban areas by using analytical hierachic process of the various predisposing factors coupled with GIS. The hazard map identified five (5) levels of landslide susceptibility from which a summary assessment and recommendations are made. The insignificant hazard, 35.3% of the total urbanized area (403 km²), requires no recommendation for human settlements, the weak hazard requiring recommendations only for large-scale works (44.1%). From moderate hazard, human settlements are possible, but vigilance is recommended for medium-scale work (16.1%). For the strong hazard (2.9%), human settlements are weakly discouraged and vigilance is recommended in the rainy season while the very strong hazards (1.6%) are strongly discouraged for human settlements.
Keywords : Landslide, Hazard, susceptibility, Analytic hierarchy process, urban growth, GIS, Bafoussam.
Spatial changes and environmental degradation in the locality of Bétaré-Oya (East Cameroon).
NDIKWÉ DOURWÉ Maurice (1), ISMAILA Ahmadou (2), AOUDOU DOUA Sylvain (3), AWÉ WANGMÉNÉ Salomon (4), SOUARÉ Konsala (5)
(1) Doctorant/Université de Ngaoundéré/Laboratoire de Géomatique
(2) Attaché de recherche, Institut de Recherche Géologique et Minière/Centre de Recherche Géologique et Minière/Cameroun
(3) Maitre de conférence/Université de Maroua (Cameroun)
(4) Chargé de cours/Université de Maroua (Cameroun)
(5) Assistant/Institut Universitaire Catholique Saint-Jérôme de Douala (Cameroun)
Abstract. The landscapes of Bétaré-Oya (East Cameroon) have been changing since the dawn of time. These changes were accentuated with the impoundment of the Lom Pangar dam in 2014. However, the environmental changes induced by the installation of the hydroelectric dam and the mining activities raise ecological problems. The objective of this study is to map spatial changes (2000-2013-2020), land use and to assess the degree of environmental pollution using multisource data. The results showed that land use is changing. These changes took a considerable proportion with the impoundment of the dam. The average annual rate of change (2000- 2013) was 7.4 compared to 39.5 (2013-2020). Analysis of soil samples revealed concentration values much higher than the WHO 2011 standard, including lead with 12274; 4265; 4607 ppm respectively for site 1; 2 and 3.
Keywords : Remote sensing, satellite images, spatial mutations, pollution, Bétaré-Oya.
Mapping using multi-criteria hierarchical analysis of landslide risk areas in the Menoua watershed (West Cameroon).
Gabriel NANFACK (1) et Julius TATA Nfor (2)
(1) Doctorant en géographie, Université de Dschang
(2) Chargé de cours, Université de Dschang
Abstract. The Menoua watershed is part of the Western Cameroon Highlands domain (H.T.O.C.). Due to its physical (located on the Cameroonian ridge) and human (high population density) characteristics, it is regularly subjected to landslides. The present study has as objective to elaborate a landslide susceptibility map of this intramontane space. By combining the hierarchical multi-criteria analysis method (AHP) with geographic information systems (GIS), we obtained the results that, this basin is full of potential sites susceptible to landslides. The very high- and high-risk susceptibility occupies approximately 55.91 km², or 9% of the total area of the basin. The most critical and determining factor of landslide occurrence is the slope with a score of 0.44. In the context of a growing human occupation of areas at risk in this basin, the landslide susceptibility map designed could be a good decision-making tool with a view to initiating integrated management of this specific area by ensuring the protection of people and property.
Keywords : Landslide, H.T.O.C., AHP, GIS, Menoua watershed.
Landslide Geophysical Risk Modeling Using Multi-Tiered Geospatial Data for Southern California.
Reni Bibriven LILA (1)
(1) Assistant Lecturer, University de Ngaoundéré – Cameroun
Abstract. Landslides impact thousands of people and damage billions of dollars of infrastructure each year. Mitigation can be difficult and expensive when detailed risk and hazard maps are not available to local planners. This study uses a probability distribution function and fuzzy multi-criteria technique to model landslide susceptibility based on the frequency of landslide occurrence with the ultimate goal of mapping both the relative risk of landslides and the hazardousness of the built environment around the cities of Ventura and Santa Barbara, California. Multi-criteria decision analysis is perhaps the most fundamental of decision support operations within a geographical information system setting. For this study, to create a successful landslide susceptibility model, a data driven model of landslide occurrence frequency (LOF) and a knowledge base model of fuzzy operators were combined for landslide susceptibility modeling. The resulting geophysical risk model provides a reliable, efficient ranking of landslide susceptibility within the study area based on the integrated geophysical risk model and the geomorphological attributes of the study area. This research demonstrates that, by leveraging a multi-tiered modeling process that involved both primary and secondary data, Geoscientists and geophysical risk managers can develop high-resolution landslide risk susceptibility assessments suitable for land-use and settlement planning at the local scale.
Keywords : Landslides Vulnerability, Fuzzy Logic, Multicriteria, Risk Exposure, Hazard, Management, GIS, Ventura and Santa Barbara Counties, California.
Land use dynamics in Dizangue (Cameroon) from 1975 to 2019 and impact on the Ossa lake wildlife reserve.
Ghislain NYEMBE ETAME (1), Eric François MEYENGUE (1), Marlyse NANKAP NDJANGUE (2), ABOUBAKAR (2), Yolande EKOSSO EBOUELE (2), Aloysisus KOTHEM LEBGA (2), Chrétien NGOUANET (1)
(1) Institut National de Cartographie (Cameroun)
(2) Laboratoire de Télédétection pour la Stéréorestitution (LATIS)
Abstract. The objective of this work is to analyze the impact of land use dynamics on the Lake Ossa wildlife reserve. The methodology consisted first of all in the collection of secondary data, which was used for documentary research and for the collection of certain geospatial data coupled with field visits and interviews with managers of agro-industries. Then the processing of satellite images consisting of supervised classifications of Landsat and Sentinel images in order to assess the dynamics of land use classes over 44 years. The results obtained show that the areas of agro-industries have evolved to 30,000 ha, followed by shifting crops and fallows at around 5,000 ha, built up to 600 ha, hydrography as well as mangroves while forests regress by -37,124 ha from their original area. The consequences are essentially: an irreversible loss of forest biodiversity, risk of great water pollution and a threat to the preservation of the aquatic fauna of Lake Ossa. This thematic is consistent with the issue of preserving biodiversity in general and managing protected areas in particular and is part of the theory of environmental security.
Keywords : Dynamics, impact, Dizangue, Lake Ossa wildlife reserve.
Contribution of the Geographic Information System (GIS) in hydroagricultural development in East Batha in Chad.
Paulin GOTILO (1), Vincent MOUTEDE-MADJI (2)
(1) Assistant au programme 3PA du Programme Alimentaire Mondial (PAM)
(2) Maître-Assistant CAMES, Enseignant-Chercheur
Abstract. Located in the Sahelian zone with low rainfall, Batha-Est is a department of the Province of Batha, which covers an area of 12,200 km² with a population estimated at RGPH2 at 223,309 inhabitants of which 53% are women. It has been hit by poverty for several decades because of many natural and human factors limiting its development. These problems had repercussions on production, accentuating the poverty of the populations. The interest of this work is to show the importance of GIS in planning. The objective is to study the contribution of GIS in hydro-agricultural developments in Batha-Est. Thanks to documentary research, questionnaire surveys, interviews, focus-group and direct observations, we collected the data which were used to write this article. The results of this study show that agro-pastoral activities are the main sources of income for the population, but do not allow them to cope with food insecurity. Thus, market gardening activities, the recession cultivation are the means of resilience, GIS can better help to increase its production.
Keywords : East Batha, GIS, hydroagricultural development, Flood culture, market gardening, Resilience.
Contribution of GIS in monitoring of reforestation activities in forest School of NFS of Mbalmayo (Cameroon).
Daniele Roseline BIKIE MINDANG (1), Philippes MBEVO FENDOUNG (2)
(1) École Nationale des Eaux et Forêts (ENEF) de Mbalmayo (Cameroun)
(2) Université de Yaoundé, Doctorant en géographie physique et Géomaticien
Abstract. The National Forestry School of Mbalmayo has a Forest School and Research Forest which is continuously being exposed to anthropic pressure which causes its degradation. For several years, reforestation activities have been carried out to restore this forest cover. However, few data are available on the area already reforested and also on the location and floristic composition of the plots reforested each year. The aim of this study is to geolocate, using GIS tools, the plots reforested between 2015 and 2019. But also, to give the surface area and a floristic composition of each plot. This work is made possible by GPS tools and ArcGIS 10.3.1® software, which facilitated data collection and analysis. It follows that, from 2015 to 2019, an area of 5.9 ha of forest was reforested, which area is spread over 43 plots (11 monospecific plots and 32 polyspecic plots). 3878 plants have been inventoried belonging to 19 species. GIS facilitates the monitoring of reforestation activities.
Keywords : GIS, Reforestation, Forest School, Landscape restoration, Mbalmayo.
An appraisal of wetland ecosystems of the Bamenda City in Cameroon : characteristics and services.
Valentine YUNINUI (1), Toumba OUMAROU (1), Michel TCHOTSOUA (2)
(1) Assistant enseignant, Université de Buea (Cameroun)
(2) Professeur, Université de Ngaoundéré (Cameroun)
Abstract. Wetlands in their natural state are immensely important environments that support human live through its direct and indirect services. Increasing population pressure has led to the draining and filling of wetlands for more competitive uses. This is further augmented by the indiscriminate dumping of unsorted waste and for these reasons, the wetland ecosystem of the Bamenda City is gradually being transformed and polluted thereby making them vulnerable. This paper therefore does an appraisal of wetlands in the Bamenda City. Using remote sensing techniques and field observation, data was collected and analysed. The findings indicate that there are two main types of wetlands in Bamenda City with six sub-types. These wetlands were found to be distributed in all three municipalities of the Bamenda City in varying proportions. These wetlands cover an area of 65.973km2 which is approximately about 11.738% of the total surface area of the Bamenda City. It was also found that wetlands in the Bamenda City provides regulatory, cultural, provisional and ecosystem support services.
Keywords : Wetland ecosystem, ecosystem services, Remote sensing, Bamenda City.
Peasant perception of the impacts of nutgrass cultivation (Cyperus esculentus L.) on soil degradation in Aguié department (Niger).
Rabiou ABDOU (1), Hadiza KIARI FOUGOU (2), Saïdou MAIDA ARGI (1)
(1) Université de Zinder, Faculté des Sciences, Département de Biologie (Niger)
(2) Université de Diffa, Institut Supérieur en Environnement et Ecologie (Niger)
Abstract. In a context of agricultural natural resources degradation, our study focuses on impacts perception of nutgrass cultivation (Cyperus esculentus L.) on soil degradation in Niger principal production area. Thus, this study is based on documentary research, direct observations and field surveys. The results of this study indicate that nutgrass cultivation practices contribute on soil degradation in this zone. All of farmers surveyed have a good reading of the soil degradation. In fact, 84% blame agricultural activities following the absence of fallow. In addition, 58.6% of these operators report climate change. According to 48% of the sample, the nutgrass crop can degrade soils but 41.6% answer no and 10.4% say nothing. 74.6% state that the surface condition of soils is deteriorating compared with 22% who think it is good and 2.4% degrade it. According to 73.4% of the farmers surveyed, the soils of the nutgrass fields are poor and 26.6% consider them fertile.
Keywords : Aguié, Impacts, Nutgrass, Soil, Soil degradation.
Anthropogenic pressures and degradation of surface water in San-Pedro (Côte-d'Ivoire).
Florent GOHOUROU (1), Quonan Christia YAO-KOUASSI (2), Émile Aurélien AHUA (3)
(1) Enseignant-Chercheur, Maitre-Assistant, Université Jean Lorougnon Guédé (Daloa – Côte d’Ivoire)
(2) Enseignant-chercheur, Maitre-Assistant, Université Jean Lorougnon Guédé (Daloa – Côte d’Ivoire)
(3) Université Félix Houphouët Boigny (Abidjan, Côte d’Ivoire) / Université de Nantes (LEGT, UMR 6554, France)
Abstract. From a sustainable development perspective, the coastal areas degradation and pollution is today at the heart of the concerns of the social sciences, particularly geography. Thus, this study, which lends itself to this approach, shows the various threats to water resources in the city of SanPédro. Based on a field survey and a matrix analysis, the study allowed us to show that the demographic pressure and the weight of human activities strongly contribute to the degradation of water resources. This situation results in health and environmental risks. Also, it enabled us to observe that the non-treatment of wastewater and household waste and backfill practices are the main factors of degradation of these waters. Our results also confirm that the socio-spatial organization of the city of San-Pédro increases the vulnerability of water resources. The disparities observed, the factors explaining the spatial relativity of the phenomenon and the diversity of the situations have shown the complexity of the causes and the dynamics involved. Better management of human activities and social practices are all solutions to maintain all economic activities and preserve the water resources of the city of San-Pédro.
Keywords : San-Pédro, water resources, population, human activity, degradation, health risk.
Oil palm production: a panacea for rural development in Mamfe sub division in the south west region (Cameroon).
Johnson MODIKA EGBE (1), Sylvester TABOT (2)
(1) Enseignant, Département de Géographie, Université de Douala (Cameroun)
(2) Doctorant, Département de Géographie, Université de Douala (Cameroun)
Abstract. The paper examines the production of oil palm and its contribution to rural development in Mamfe Sub-division. In order to attain this objective a systematic random sampling of 350 oil palm producing households from 8 villages in the Sub-division constituted the sample frame. Data collected from the field were treated and analyzed statistically with the use of cartographic soft-wares: CorelDraw12, MapInfo, Microsoft Excel and results were presented on tables, figures and photos. Findings revealed that favorable ecological conditions in terms of sandy soils and temperatures that range between 26○C to 29○C, and rainfall that also oscillate from 1500 to 2000mm are pre-conditions for oil palm production. This is complemented with dynamics of energetic youthful population that ensure the survival of the activity in Mamfe. The second result demonstrates that there are two types of oil palm cultivated concentrated in zones according to species: improved specie (Tenera) and un-improved specie (Dura) these zones of segregation are easily noticed among the farmers of peasant populations of Mamfe Sub-division. Generally, the unimprove specie out-weighs the improved species of palms cultivated in the area. The third finding shows that the peasants derived much income from palms activity and this permit them to construct private residents, about 70% of the 350 oil palm farmers sampled own their own houses in which they live in and close to 60% of the peasants own block houses, send their children to school and their standard of living is improved owing to the provision of protein food. Local development in Mamfe Sub-division is reflected in the evolution of the activity based on villages’ development. The fourth and last results depicts that the contribution of oil palm production to socio economic development is unsatisfactory because it is plague by several problems amongst which include, neglect by elites, inadequate capital etc. The temporal closure of the lone oil palm cooperative; MOPCOOP due to succession crisis is partly responsible for the unsatisfactory oil palm production and socio-economic development in Mamfe Sub-division. This article proposes the reinstatement of MOPCOOP amongst other measures; this structure is considered as a corner-stone to the development of the sub-sector.
Keywords : Oil palm, production, Panacea, Development, Mamfe.
Women's organizations and microfinance facing the challenges of empowerment and local development : the case of EXPRESS MIA in N’djamena.
Vincent de Paul ALLAMBADEMEL (1), Ndikwé TCHAGO (1)
(1) Département de sociologie, Université de N’Djaména (Tchad)
Abstract. Poverty is a social phenomenon affecting many countries worldwide including Chad. Poverty affects nearly 57% of its population. Vulnerable people such as widows, orphans, and the unemployed are becoming more and more numerous. Therefore, microfinance appears to be an instrument to fight poverty. Through this paper, we want to show how a microfinance organization such as EXPRESS MIA helps to fight against poverty and especially women's poverty in urban areas. EXPRESS MIA is a second-class microfinance organization in N'Djamena. In this research, we used EXPRESS MIA data, interviews with key informants and recipients to help us improve the work. We also used a camera for shooting. A voice recorder allowed us to faithfully record the interviews with our respondents in the field. The results highlight the value of lending credits to a segment of the population struggling to get out of poverty. The Poor’s Bank (Express Mia) grants micro-credits to women who organize themselves and gradually get out of poverty.
Keywords : N'Djamena, micro-credits, women, poverty, microfinance, EXPRESS MIA.