Analysing the Potential Impact of Climate Change on the Hydrological Regime of the Upper Benue River Basin (North Cameroon)

In this study, we analyse the climate variability in the Upper Benue basin and assess its potential impact on the hydrology regime under two different greenhouse gas emission scenarios. The hydrological regime of the basin is more vulnerable to climate variability, especially precipitation and temperature. Observed hydroclimatic data (1950-2015) was analysed using a statistical approach. The potential impact of future climate change on the hydrological regime is quantified using the GR2M model and two climate models: HadGEM2-ES and MIROC5 from CMIP5 under RCP 4.5 and RCP 8.5 greenhouse gas emission scenarios. The main result shows that precipitation varies significantly according to the geographical location and time in the Upper Benue basin. The trend analysis of climatic parameters shows a decrease in annual average precipitation across the study area at a rate of -0.568 mm/year which represents about 37 mm/year over the time 1950-2015 compared to the 1961-1990 reference period. An increase of 0.7°C in mean temperature and 14% of PET are also observed according to the same reference period. The two climate models predict a warming of the basin of about 2°C for both RCP 4.5 and 8.5 scenarios and an increase in precipitation between 1% and 10% between 2015 and 2100. Similarly, the average annual flow is projected to increase by about +2% to +10% in the future for both RCP 4.5 and 8.5 scenarios between 2015 and 2100. Therefore, it is primordial to develop adaptation and mitigation measures to manage efficiently the availability of water resources.

3D Modelling from New and Existing Gravity Data of an Intrusive Body in the Northern Part of Kribi-Campo Sub-Basin in Cameroon

A new gravity survey was carried out in the northern part of the onshore Kribi- Campo sub-basin in Cameroon. The data were incorporated to the existing ones and then analyzed and modeled in order to elucidate the subsurface structure of the area. The area is characterized in its north-western part by considerably high positive anomalies indicative of the presence of a dense intrusive body. We find, 1) from the analysis of the gravity residual anomaly map, the high positive anomalies observed are the signature of a shallow dense structure;2) from the multi-scale analysis of the maxima of the horizontal gradient, the structure is confined between depths of 0.5 km and 5 km;3) from the quantitative interpretation of residual anomalies by spectral analysis, the depth to the upper surface of the intrusive body is not uniform, the average depth of the bottom is h1 = 3.6 km and the depths to particular sections of the roof of the intrusion are h2 = 1.6 km and h3 = 0.5 km;4) and the 3D modeling gives results that are suggestive of the presence of contacts between rocks of different densities at different depths and a dense intrusive igneous body in the upper crust of the Kribi zone. From the 3D model the dense intrusive igneous block is surrounded by sedimentary formations to the south-west and metamorphic formations to the north-east. Both formations have a density of about 2.74 g/cm3. The near surface portions of this igneous block lie at a depth range of 0.5 km to 1.5 km while its lower surface has a depth range of 3.6 km to 5.2 km. The shape of the edges and the bottom of the intrusive body are suggestive of the fact that it forms part of a broader structure underlying the Kribi-Campo sub-basin with a great influence on the sedimentary cover.

Subsurface Structural Mapping Using Combined Terrestrial and Grace Gravity Data of the Adamawa Plateau (North-Cameroon)

In order to analyze and determine the geological structures of the Adamawa plateau, the terrestrial gravity data were combined to data computed from GGM02C gravity model. The dense gravity net obtained were further introduced into qualitative and quantitative interpretations. The resulting Bouguer anomaly map obtained from combined data shows NE-SW direction which nearly coincides with the main direction of the fractures affecting the basement in the region and indicates strong gradients marking the presence of discontinuities between heavy and negative gravity anomaly. In order to conduct the quantitative interpretation of the combined gravity data, three profiles were drawn on the residual Bouguer anomaly map and therefore were interpreted using spectral analysis method and 3D density inversion. The knowledge of the depth and density of the geological structures show an uplift of dense rocks under the granite-gneiss substratum. This dense material found in the ENE-WSW direction of the Adamawa Plateau is interpreted as basaltic intrusion probably resulting from tectonic processes. According to this study, the depths of 3.83 km and 9.62 km are the new values of depths obtained for futures investigations in the Adamawa plateau.

Refinement of Bouguer anomalies derived from the EGM2008 model,impact on gravimetric signatures in mountainous region:Case of Cameroon Volcanic Line,Central Africa

Global geopotential models have not included the very high frequencies of the Earth’s external gravity field.This is called omission error.This omission error becomes more important in mountainous areas(areas with highly variable topography).The work reported here consists in reducing the omission error in measurements of Bouguer gravity anomalies,by refining the global geopotential model EGM2008 using the spectral enhancement method.This method consists in computing the residual terrain effects and then coupling them to the gravimetric signal of the global geopotential model.To compute the residual terrain effects,we used the Residual Terrain Model(RTM)technique.To refine it required a reference surface(ETOPO1)developed up to degree 2190(the maximum degree of the EGM2008 model)and a detailed elevation model(AW3D30).Computation was performed with the TC program of the GRAVSOFT package.The topography of the study area was assumed to have a constant density of 2670 kg/m3.For the inner and outer zones,the respective integration radii of 10 km and 200 km have been chosen.We obtained very important RTM values ranging from−53.59 to 34.79 mGal.These values were added to the gravity anomalies grid of the EGM2008 model to improve accuracy at high frequencies.On a part of the Cameroon Volcanic Line and its surroundings(mountainous area),we made a comparison between the residual Bouguer anomalies before and after refinement.We report differences ranging from−37.40 to 26.40 mGal.We conclude that the impact of omission error on gravimetric signatures is observed especially in areas with high variable topography,such as on the Cameroon Volcanic Line and around the localities of Takamanda,Essu,Dumbo,and Ngambe.This finding illustrates the great influence that topography has on accurate measurement of these gravity anomalies,and thus why topography must be taken into account.We can conclude that in preparing a global geopotential model,a high resolution DTM must be used to decrease the omission error:the degree of expansion has to increase in order to take the higher frequencies into account.The refined Bouguer anomalies grid presented here can be used in addition to terrestrial gravity anomalies in the study area,especially in mountainous areas where gravimetric data are very sparse or nonexistent.

Evidence for the Upwelling of Mafic Bodies into the Upper Crust beneath the N40-50°E Branch of the Pan-African Central Cameroon Shear Zone from Gravity Studies

The existence of mafic bodies at mid crustal level beneath the Pan-African Central Cameroon Shear Zone is still a matter of debate. To provide additional constrains on this issue, the crust of the west region of Cameroon has been investigated using gravity data. Analyses of these data show N40-50°E oriented iso-anomal contours in the Bafoussam area, interpreted as the N40-50°E branch of the Central Cameroon Shear Zone. In addition, spectral analysis and 2.5D gravity modeling reveal intrusions of mafic bodies at depth between 3.2 and 14.2 km under N40-50°E aligned volcanic centers, namely Mt Bambouto and Mt Mbapit. The above observations suggest a structurally controlled emplacement of the mafic bodies. In the light of the recent geophysical data, the interaction between the NE-ward channel flow operating at the bottom of the lithosphere or the asthenosphere upwelling and the Cameroon Shear Zone could better explain the magma upwelling in the upper crust. This result is the novelty of the present work.

Monitoring and Environmental Assessment of Seawater in West Central Africa: Case of the Kribi Industrial and Urban Port Complex in Cameroon, Guinea Gulf

This study is the first of a series of a project on the development and implementation of environmental protection policies, before, during and after the construction of the Kribi Industrial and Urban Port Complex (KIPC). The results will equip the State and scientific structures concerned with the protection of people, water resources and the environment as a whole. This includes reference data on the state of marine pollution in the region dating from the end of realization of the first phase of KIPC known as Kribi Deep-Water Harbor (KDWH). Accordingly, the aim of this work is to assess the current state of KIPC and its surrounding by quantifying the preliminary parameters of suspended matter (SM);to analyze the physical and chemical parameters, chemical pollution indicators for anions and major cations and organic pollution indicators of four water samples taken from four different sites in the project area by filtration and weighing, pH meter, turbid meter, titration, colorimetry and titrimetric methods. The analysis of these samples and these parameters provides results which are slightly similar to international standards. This suggests that the environment remains relatively healthy. Hence, continuous management and monitoring of the parameters and pollution factors is strongly recommended.

Structure of the Crust Beneath the South Western Cameroon, from Gravity Data Analysis

The study area is located in the south western Cameroon and includes part of the Cameroon Volcanic Line (CVL). Volcanic activity has been recorded in this area, precisely on the Mount Cameroon which recently erupted in 2002. In addition, deadly carbonic gas was emitted by crater lakes (Monoun and Nyos) in 1984 and 1986 respectively. Potential field model EGM2008 has been used to investigate the structure of the crust. A regional/residual separation is performed using upward continuation and polynomial separation methods. The results from this operation show a similarity between the regional anomalies resulting from both methods. The regional anomaly maps present an increasing gradient trending ENE-WSW above and below latitude 5?N. Moreover, six nearly parallel profiles were drawn on the CVL in addition to two other profiles at the northern edge of Congo craton. These profiles were used to estimate the depths of the Moho discontinuity and some shallow sources by the means of the Bouguer and the residual anomalies respectively. The results show that the Moho discontinuity depths vary from 19 - 25 km (under Mount Cameroon) to 28 - 34 km (in Kumbo), while the southern neighbouring zone presents a Moho discontinuity depth ranging between 23 - 31 km (in Ngambe) and 22 - 32 km (in Eseka). These findings agree with the previous seismic and gravity researches lead in the area. EGM2008 is therefore a reliable tool to investigate the subsurface structures.

In vitro biological activities of aqueous extracts of Tetrapleura tetraptera(Schumach. & Thonn.) taub. and Aframomum citratum(C. Pereira) K.Schum from three Agroecologic Zones in Cameroon

Objective:To investigate some phytochemical constituents and biological activities of twelve samples of Tetrapleura tetraptera(Schumach&Thonn.)taub.and nine samples of Aframomum citratum(C.Pereira)K.Schum fruits collected in the bimodal forest zone(ZONEⅤ),the unimodal forest zone(ZONEⅣ)and the highlands zone(ZONEⅢ)in Cameroon.Methods:Fresh fruits extracts were obtained by aqueous infusion(100℃during 15 min)and evaluated by spectrophotometric methods for total polyphenol(TPP),total flavonoids(TFLV)contents and antioxidant(DPPH,total antioxidant capacity by the phosphomolybdenum method,iron reducing power or ferric reducing antioxidant power and inhibition of beta carotene discoloration assays)and anti-inflammatory(inhibitions of protein denaturation and 5-LOX represented by INH.PROT and INH.5-LOX respectively)properties.Principal component analysis was performed.Results:For both species,fruits from ZONEⅤhave the highest TPP,TFLV levels and biological activities.TPP and TFLV content of Aframomum citratum and Tetrapleura tetraptera fruits are positively and significantly(P<0.05)correlated.The biological activities of all extracts(0.25,2.5,25,250 mg/mL)were dosedependent and the extracts have shown strong antioxidant and antiinflammatory activities,but less than references(ascorbic acid,diclofenac,quercetin,and butylated hydroxytoluene).There was a positive correlation between TPP,TFLV and total antioxidant capacity,ferric reducing antioxidant power,and inhibition of beta carotene discoloration assays,and inverse correlations were observed with the IC50(g/mL)of DPPH,INH.5-LOX and INH.PROT assays for both species.Conclusions:The fruits exhibit variabilities and those from ZONEⅤfor both species are economically and healthcare challenging for herbalists,pharmaceutical firms,scientists and consumers.Indeed,most important extraction yield of bioactive compounds correlated with significant biological activities and the use of less material compared with an implementation in other Agro-ecologic Zones with the same results are noted.

Sedimentological Studies of Alluvium Deposits along Ngovayang-Bipindi of Lokoundje River,Southwestern Cameroon

In an area of about 305 km2, Seventeen stream sediment samples were taken from alluvium on the banks and floodplain of the Lokoundjé River and its tributaries. Sand samples after being dried in an oven, are subjected to sedimentological analyses in laboratory. Amongst the analysis carried out;the particle size analysis helped to establish a precise textural description of the sediment and to understand the active mechanisms which occur during transport and particle deposition. The morphoscopy of quartz grains consists in determining the mode and duration of transport of the grains, thus allowing reconstructing the geological history of the latter. Heavy minerals are suitable to know the nature of the rock in which they come from and equal to specify their distributing province. The morphometry of pebble makes contributes for a better understanding to apprehension of the agents responsible for the transport of these materials. It appears that the alluvium of the Lokoundjé and its Bipindi tributaries are very fine to coarse. They are well segregated, classified, and homometric. It is the result of the actions of a hydrodynamic turbulent which is sometimes abrupt. From a morphoscopic point of view, using a binocular microscope, grains mainly belong to three categories based on their surface appearance: Grain unworn, the sub-dull and dull shiny. From the morphometric point of view, there is evidence of flattening and dissymmetry of pebbles which are slightly worn to form sub-spherical shapes. With regard to the study of heavy minerals, it has identified two mineralogical processions, which include a metamorphic process with the presence of Sillimanite and Andalusite. In addition, there is the presence of minerals such as green’s Hornblende, Tourmaline, and reflecting magmatic distribution. However, there are specific minerals such as zircon, which can be economically viable where the contents sometimes exceed 10 kg/m3. In the same vein, it has been noted the presence of gems like Topaze and Monazite which are real precursor auriferous accumulation.

Dynamics of the Vegetation Landscapes of the Mbere Valley’s National Park and Its Southern Periphery

The present study is about the dynamics of the vegetation landscapes of the Mbere Valley’s National Park and its southern periphery (MVNP). The physical and human characteristics of this area, translated by an inter-twining of natural, anthropic and institutional factors, predispose its vegetation cover to a dynamic which can be progressive or regressive according to the dominant factor. The present study aims at reconstituting the various space-time variations of the MVNP vegetation cover and its periphery between 1987 and 2014, and at determining the processes and the factors having supported these space-time variations of vegetation cover. The methodological step consists of an association of fieldwork and remote sensing in order to characterize the vegetation cover, to reconstitute the evolution of the vegetation cover and to determine the main factors of the processes of this evolution or dynamic. The diachronic analysis shows that the dynamics of the vegetation cover was marked by a progressive evolution between 1987 and 1999, and a regressive evolution between 1999 and 2014. On the base of fieldwork observations and the socio-economic surveys, it arises that the dynamics of the vegetation cover of the valley of Mbere and its periphery is subjected to the combined influence of the natural conditions, from the recurring anthropic disturbances as well as the weight of regulatory measures.

Interpretation of locally high gravity anomalies using terrestrial gravity data in Bagodo, North Cameroon

In this work,we interpreted gravity data to determine the structural characteristics responsible for high-gravity anomalies in Bagodo,North Cameroon.These anomalies had not previously been characterized through a local study.Thus,we undertook a regional-residual separation of the gravity anomalies by using the polynomial method.Geophysical signatures of near-surface small-extent geological structures were revealed.To conduct a quantitative interpretation of the gravity anomalies,one profile was drawn on a residual Bouguer anomaly map and then interpreted by spectral analysis,the ideal body solution,and 2.5-dimensional modeling.Our results showed that the intrusive body in the Bagodo area consists of two trapezoidal blocks.The first and second blocks have roofs approximately 7.5 and 14 km deep,respectively,whereas their bases are approximately 17 km deep.These values are in agreement with those obtained by the ideal body solution,which showed two cells with a density contrast of 0.3 g·cm^(−3) in comparison with the surrounding rocks.The density of this body was estimated to be approximately 3 g·cm^(−3).The topography of these rocks showed that they are basaltic rocks that would have cooled in fracture zones as an intrusion.

Local Initiatives of Land Rehabilitation in the Sudano-Sahelian Region: Case of <i>Hardé</i>Soils in the Far North Region of Cameroon

Local initiatives of hardé soils rehabilitation in Maroua region have been analyzed. Fieldwork consisted of conducting observations and surveys beside farmers in two study sites, Mizileng and Zokok. Investigations on perception of land degradation signs by farmers show that appearance of encrusted surfaces and loss of vegetation cover are signs more expressed in both study sites. Causes expressed include acceleration of water and wind erosion processes, excessive falling of trees, inappropriate farming techniques and climatic hazards. The main consequences are declining of crop yields, lack of farming land and loss natural pastures. Rehabilitation actions undertaken by local communities surveyed include earth dikes, tillage including cart or hoe ploughing, application of organic matter, integrating farming techniques such as fallowing, association and rotation of crop, and lastly, parking of animals on plots to be rehabilitated. Populations assert in their majority perceive in six months to three years signs of real change on planning plots. Constraints to those rehabilitation actions include material requirements that are mostly not available or accessible to farmers in the study area and access to land. Globally, there is no integration of local knowledge in the implementation of projects and consequences are localized and ephemeral efficiency, but also not conclusive results. Implementation of an innovation in rural areas must take into account the factors of ownership and inscribe in a well-defined trajectory. This trajectory must be dynamic and reflexive where local knowledge will cope with expert knowledge to ensure impact and sustainability of innovation.

Geoelectric Structure of the Crust along the Mbere Trough (South Adamawa) from Audio-Magnetotelluric Data

The South Adamawa trough represents a major structure associated to the tectonic activity in the Adamawa region. The Mbere and the Djerem troughs represent the eastern and the western parts of the South Adamawa trough respectively. The audio-magnetotelluric (AMT) method is used to study the Mbere trough and to bring out tectonic features that affect the basement of this region during the Cretaceous. From analysis and interpretation of AMT data, based on pseudo-section and geoelectric section, two geologic models are constructed across the trough at Belel and Nyambaka. Those models bring more information on the sediments thickness and the borders faults of the trough compared to previous studies. The results shows that the Mbere trough is dissymmetric, and bounded on its northern side by an intra-gneissic fault and on its southern side by two faults with at least one considered as a faulted contact between the granitic and gneissic rocks. The sediments filling of the trough are consist mainly of conglomerates on which lay sandstones. The thickness of these sediments is about 2060 m at Belel and decreases to about 1800 m at Nyambaka, with a low sandstones thickness, which does not exceed 360 m. The basement consists of granite in the South of the trough and gneiss in the North, with resistivity more than 10,000 Ω.m. The Moho is located between 25 and 35 km in the South Adamawa region.

Research of Directory Service Model for Geographic Information

With the deepening application of geographic information web services, as a significant part, geographic information directory service sets up a service transaction platform between the service providers and the service requestors, providing one-stop registration, access and management functions of geographic information web services, so it is very important to carry out the research on geographic information directory service. According to the domestic and overseas metadata standards, the service expression-oriented metadata information model for geographic information web service is established, and the discovery mechanism dominated by geographic information service registration and active discovery is realized accordingly. After that, overall design of directory service model is made, and finally the research results are integrated into the geographic information service software NewMapServer and deployment test is made under the Google Cloud Environment Google App Engine, providing a certain reference for sharing the Smart City construction achievements.

Evaluation of the Advanced Minning Front Craft in and around National Parks of the Benue and Bouba-Ndjidda in North Cameroon

This study focuses on the assessment of “the advancement of the mining front (gold panning) in and around protected areas”. The aim of this article is to evaluate, using geomatics tools, the recent advance of the mining front (gold panning) in Benue National Park (PNB) and Bouba-Ndjidda (PNBN) for their planning purposes. We adopted a methodological approach articulated from the field surveys to the processing of satellite images and the integration of the data into a GIS. Thus, 30 gold panning sites were visited, including 16 in the PNB and 14 in the PNBN. From the mapping of the pressures exerted by this activity, it appears that 143.8 km and 73.8 km of cumulated linear were exploited respectively in the GNP and the PNBN;moreover, the results allowed us to detect that the surfaces degraded by gold panning are more important in Benue than in Bouba Ndjidda. The massive influx of migrants from the more populated areas of the Far North of Cameroon as well as neighboring countries (Chad, Nigeria and the Central African Republic) has not only brought about the growth of a pioneering agricultural front, but also the mining front, following the gold rush from 2009;which has led to huge environmental consequences in these protected areas.

Application of Coefficient of Anisotropy to the Geophysical Prospecting of Campo—Ma’an Area of the Ntem Complex in Cameroon

Audiomagnetotelluric data were acquired for 10 sounding stations in open fields and roads along the main highways from Campo to Ma’an in Cameroon. An application of the coefficients of anisotropy was used to determine the tectonic settings and the nature of the contacts between the sedimentary formation of the Kribi-Campo basin and the cratonic Ntem Complex. The results of this study show that apart from the sedimentary formation, the metamorphic formation in this area comprises two metamorphic blocks: a regional metamorphic block which might be igneous or granitic in nature and composition and seem to be Precambrian and plutonic in origin and a contact or transitional metamorphic block, which might represent schist or gneiss rocks. The contact or transitional metamorphic block might be as a result of a long period of contact between regional metamorphic rocks and rocks of sedimentary formation. These contact/transitional metamorphic rocks which are found sandwiched between rocks of sedimentary formation and rocks of the regional metamorphic block and at varied depths confirm the existence of vertical and sub-vertical contacts between the Kribi-Campo basin and the cratonic Ntem complex. Two types of rock contacts have been identified: a sedimentary-schist contact which is found at the boundary between the sedimentary formation and the transitional metamorphic block and a schist-granite contact between the transitional and regional metamorphic blocks. Two main formations: a sedimentary formation, which is found in the Kribi-Campo sub-basin and the Ntem River bed and its flood plains and the metamorphic formation which includes both the transitional and regional metamorphic rocks have also been identified in the area of study. Subsurface rocks and rock materials have been observed to be highly resistive and occupying almost the entire subsurface in the area of study confirming the high vertical tectonic stability of the Ntem Complex even at contact with the sedimentary Kribi-Campo basin.

Determination of Structural and Geometrical Parameters of the Kribi-Campo Sedimentary Sub-Basin Using Gravity Data

In order to produce a more detailed structural and geometrical information, and determine sediments thickness along the Kribi-Campo sub-basin, statistical spectral analysis and horizontal gradient analysis of residual anomalies coupled with the Euler deconvolution approach were applied on the gravity data in the area. The results obtained from the 2D spectral analysis on anomaly grids gave a depth to the basement rocks of the basin from 0.60 km to 3.93 km. This represents the thickness of the sedimentary formations overlying the basement. The interpretation of the spectral analysis results indicated that the potential hydrocarbon field areas are situated between Kribi and Lolabe and at Campo given that those areas have the highest sedimentary thicknesses values. From the analysis of the horizontal gradient, deep faults mainly striking SW-NE have been traced and a structural map of the area has been produced. By applying the Euler deconvolution method to the gravity data, information about the depth and trend of the main subsurface structures have been obtained.

Exploration of Potential Ore Deposits along the Cameroon Volcanic Line from Gravity and Magnetic Studies

A gravity and magnetic study has been carried out along the continental part of the Cameroon Volcanic Line (CVL), with the aim to explore the possibility of ore’s presence into the basement of this region. Different processing techniques have been applied, including the isostatic residual, the analytic signal and the Euler deconvolution to compute the Bouguer and magnetic anomalies. Following Euler solutions (result of Euler deconvolution) and the analytic signal results, four profiles crossing main structures on the isostatic residual have been used to enhance the structure of intrusions in the studied area. Despite the lack of constraints in the studied region, the results show that the basement is intruded by bodies of different density (2.57 g/cm3 to 2.87 g/cm3), different size and shape, with depths between 1 and 10 kilometers. These bodies have been interpreted as old rocks then as potential reservoirs of rare ores. In addition, volcanic rocks modeled have constituted potential reserves of other ores like graphite, sulfur, copper, iron.

Analysing Mismatches in the Demand and Supply of Classrooms in the Basic and Secondary Education Sectors in Cameroon

The present work analyzed the contribution of Cameroon’s public contracts and territorial planning policies toward the reduction of classroom disparities across the country. Many localities in Cameroon suffer due to misallocation of classrooms on one hand and inefficient public contracting-execution system on the other hand. This paper uses a hypothetico-deductive method to understand the nexus of public contracting-territorial planning within the educational sector in Cameroon. To do this we made use of existing infrastructural data collected from various Ministerial Departments and public contracts data from 2016 to 2022. Findings show that there is a great disparity of existing classrooms, injustice in the allocation of classrooms and bad governance practices in the award and execution of allocated classrooms that directly contribute to this uneven repartition. At the national scale, the Centre and Littoral regions seem to be saturated with about 20,574 and 10,436 classrooms respectively, the Far North which is part of the Priority Education Zone is in dying need of about 11,293 classrooms while on the local or regional scale these two saturated regions show some degree of insufficiency in term of available classrooms. Therefore, much needs to be done by the Cameroonian authorities in order to ensure inclusive, equitable quality education and promote lifelong learning opportunities for all as stipulated by the Sustainable Development Goal 4.

Reference Ellipsoid Parameters of Cameroon from GPS Data

The standard spheroidal reference surface also referred as the reference ellipsoid is a part of mapping basic infrastructures of a country. In Cameroon, the ellipsoid Clarke 1880 with unknown parameters used for a long time as reference system in basic mapping, has lead to the use of World Geodetic System 1984 (WGS 84) whose parameters are well known. Meanwhile, the latter is not accurate locally due to the fact that the best ellipsoid is the one that fits very well with the local geoid. In order to look for the parameters of the local ellipsoid that fits best to the local geoid (Cameroon Geoid Model 2011 (CGM11)), the Global Positionning System (GPS) data made of 525 geodetic ground control points of the new geodetic network of Cameroon set up in 2011 were used. These GPS measures provide for each point the values of the ellipsoid height and the elevation which are used to determine the parameters of the local ellipsoid model for Cameroon through the least square form of the Molodensky analytical method. The results are given as the difference in ellipsoidal height relative to the parameters of the WGS84 ellipsoid assuming the two ellipsoids in their parallel. These results show that the obtained ellipsoid fits better to the local geoid with 1.072 m as the standard deviation value, is improved considerably in comparison to the previous studies conducted in Cameroon whose standard deviation was fairly equal to 1.679 m.