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Search Results: 1 - 10 of 7607 matches for " Philippe Nouck Njandjock "
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Geoelectric Investigation for Groundwater Exploration in Yaoundé Area, Cameroon  [PDF]
William Assatsé. Teikeu, Philippe Nouck Njandjock, Théophile Ndougsa-Mbarga, Tabod Charles Tabod
International Journal of Geosciences (IJG) , 2012, DOI: 10.4236/ijg.2012.33064
Abstract: Yaounde zone is originally characterized by the small number of aquifers and bad renewal capacity. Within the frame-work of the emergency program which aims at supplying the city with drinking water, seventeen Vertical Electrical Soundings (VES) were carried out using Schlumberger configuration in parts of Yaounde (latitude 3o- 5oN and longi- tude 11o-13oE) to determine the nature and thickness of aquifer zone and necessary geoelectrical parameters. Four to five geoelectric layers were delineated from the survey area. The first layer is the topsoil and has resistivity values ranging from 13 - 216 Ω·m and thickness is between 0.1 - 6 m. The second layer made up of clay sand and laterite has resistivity values ranging between 23 and 923 Ω·m and thickness ranged from 1 and 40 m. The third and fourth geoelectric layers consisting of clay and gneiss/migmatite with thickness varying from 1.7 - 63.3 m correspond to an aquifer horizon. Resistivity values of the aquifer ranges from 4 to 9215 Ω·m. The study indicates that average depth of the aquifer is 20 m and average thickness of the aquifer is 55 m. Soundings curves suggest several four layered geoelectrical sections KH, KQ, HK type and some five layered sections of the HKH, KHK types. KH type is dominant and can be used as reference for future studies. The resistivity survey reveals that the parameters obtained through interpretation of VES curves corroborate the litho logs of boreholes from the area.
Hydrogeophysical Parameters Estimation for Aquifer Characterisation in Hard Rock Environment: A Case Study from Yaounde, Cameroon  [PDF]
William Assatsé Teikeu, Philippe Nouck Njandjock, Dieudonné Bisso, Quentin Yene Atangana, Jean-Paul Sep Nlomgan
Journal of Water Resource and Protection (JWARP) , 2012, DOI: 10.4236/jwarp.2012.411110
Abstract: Detailed local geological and hydrogeophysical investigations were carried out for the aquifer in Yaoundé, Cameroon to delineate the architecture of different subsurface geological horizons using lithologs and generated vertical electrical sounding (VES) data. An attempt has also been made to estimate aquifer transmissivity from resistivity data. The transmissivity of the uncon?ned aquifer was computed by determining the Dar-Zarrouk parameters (longitudinal unit conductance and transverse unit resistance) and were compared with the actual field transmissivity. The results showed a direct relation between aquifer transmissivity and transverse resistance. The relationship established has therefore, been generalized in the study area in order to evaluate hydraulic conductivity and transmissivity at all the points where geoelectrical measurements have been carried out. This generalization allows one to derive maps of the product Kσ and transmissivity in the study area based on geoelectrical measurements. These maps are important in future modelling processes oriented towards better exploitation of the aquifers.
Electrical and Geological Investigations to Conduct Petrophysical Study in Douala-Cameroon Sedimentary Basin  [PDF]
Philippe Njandjock Nouck, Dieudonné Miyem, Aristide Binyam-bi-Mpeck, Quentin Yene Atangana, Simon Ngos
Open Journal of Geology (OJG) , 2013, DOI: 10.4236/ojg.2013.34031
Abstract:

Electrical and geological methods are used to conduct petrophysical study in Douala-Cameroon sedimentary basin along Yaounde-Douala National road No. 3. Studies in this region are made of three outcrops, namely: Missolè II located on the sedimentary basin of Douala, Edea and Sikoum which are outcrops of basement rocks that form the eastern boundary of the sedimentary basin of Douala. This study reveals that the rocks of the sedimentary basin of Douala are mainly composed of sandstone and clay. Both basement rocks of Edea and Sikoum are subjected to the same phases of deformation. These phases of deformation give the quartzite a particular structure that greatly influences the resistivity and density of these rocks and give it a planar anisotropy.

Water Infiltration Study from Magnetotelluric Data in the Limestone Fault Network of Mintom (South Cameroon)  [PDF]
Harlin L. Ekoro Nkoungou, Daniel H. Gouet, Philippe Njandjock Nouck, Eliézer Manguelle Dicoum
International Journal of Geosciences (IJG) , 2015, DOI: 10.4236/ijg.2015.69080
Abstract: Magnetotelluric surveys have been conducted in the Mintom area in order to evaluate the water infiltration potential of the Dja river in a limestone deposit estimated at about 350 million?m3 laying on a network of faults compromising the exploitation of this limestone deposit. The interpretation of these data shows that this network of faults is clearly highlighted as 2D/3D structures consolidated showing a low potential water infiltration through these structures. This result is confirmed by the absence of confined and induced aquifer along all the profiles. From this finding, we concluded that the exploitation of this deposit is not conditioned by the water infiltration from the Dja River.
Depositional and Structural Styles in the Logone Birni Basin (LBB), Northern Cameroon, from 3D Potential Field Modeling: Preliminary Results  [PDF]
Elad Mkoumbe, Fosso Téguia M. Estelle Eric, Eyike Yomba Albert, Njandjock Nouck Philippe, Tabod Charles Tabod
Open Journal of Geology (OJG) , 2019, DOI: 10.4236/ojg.2019.94016
Abstract: A three-dimensional model of the Logone Birni Basin (LBB) is presented by combining gravity and magnetic data and constrained by broad seismic profiles. The 3-D model has revealed the distribution of the stratigraphic formations as well as the top basement variation. Detailed structure of different stratigraphic sequences is presented for the first time for this basin and some of the sequences correlate with established sequences of the neighboring basins. The sediments pill consists of six sedimentary units dating from the Neocomian to the Quartenary. The Makary subbasin or Northern Logone Birni Basin (NLBB) is the deepest part of the basin and may hold good prospect for hydrocarbon generation and accumulation. However, the limited presence of faults and intrusive bodies decreases the possibility of thermal degeneration, contrary to the Central Logone Birni Basin (CLBB) where conditions seem to be fulfilled for possible hydrocarbon generation and maturity. The complexity of the structural pattern of the model is further enhanced by the presences of volcanic bodies, some of which lay directly on basement or interbedded with the sediments layers mainly in the CLBB.
Spectral analysis and gravity modelling in the Yagoua, Cameroon, sedimentary basin
Njandjock Nouck, Philippe;Manguelle-Dicoum, Eliezer;Ndougsa-Mbarga, Théophile;Charles Tabod, Tabod;
Geofísica internacional , 2006,
Abstract: a gravity survey is carried out in the far north of cameroon, covering an area of about 15 000 km2 in the yagoua sedimentary basin, located between longitudes 14°20' to 15°50'e, and latitudes 9°45' to 11°n. using a density of 2.7 g/cm3 for the crust and removing a second-degree trend surface for modelling, we determined the residual anomalies. further investigations provide depth of gravity sources, basement structural trend, nature of intrusive bodies and thickness of sediments in the basin. a negative anomaly of about -18 mgal near moulvouday suggests a thickness of sediments of 3.1 km extending north east. a 2.5d modelling has been carried out along two profiles p1 and p2. the depths estimated from spectral analysis and 2.5d modelling are coherent. the combination of the spectral analysis and 2.5 d modelling has led to the demarcation of the yagoua basin.
Spectral analysis and gravity modelling in the Yagoua, Cameroon, sedimentary basin
Philippe Njandjock Nouck,Eliezer Manguelle-Dicoum,Théophile Ndougsa-Mbarga,Tabod Charles Tabod
Geofísica internacional , 2006,
Abstract: A gravity survey is carried out in the far north of Cameroon, covering an area of about 15 000 km2 in the Yagoua sedimentary basin, located between longitudes 14°20’ to 15°50’E, and latitudes 9°45’ to 11°N. Using a density of 2.7 g/cm3 for the crust and removing a second-degree trend surface for modelling, we determined the residual anomalies. Further investigations provide depth of gravity sources, basement structural trend, nature of intrusive bodies and thickness of sediments in the basin. A negative anomaly of about -18 mGal near Moulvouday suggests a thickness of sediments of 3.1 km extending north east. A 2.5D modelling has been carried out along two profiles P1 and P2. The depths estimated from spectral analysis and 2.5D modelling are coherent. The combination of the spectral analysis and 2.5 D modelling has led to the demarcation of the Yagoua basin.
Water-table Control Using Ordinary Kriging in the Southern Part of Cameroon
Jorelle Larissa Meli`i,Dieudonne Bisso,Philippe Nouck Njandjock,Theophile Ndougsa Mbarga
Journal of Applied Sciences , 2013,
Abstract: In this study, application of the kriging technique for the spatial analysis of groundwater levels is shown. The data set consists of measured elevations of the water table at about 70 points during the last five years (2009-2012) in Sangmelima region (South-Cameroon). From these measurements, an experimental variogram was constructed to characterize the spatial variability of water level. Pentaspherical, spherical, exponential, power, linear and gaussian variogram models were fitted to the experimental variogram. The model having the least error 1.77 and 0.001 according to the cross validation criteria was selected by comparing the observed water-table values with the values predicted by empirical variograms. It was determined that, linear model is the best fitted model for the studied area and can be used as tool to conduct desertification control process in this equatorial zone.
Structure of the Crust Beneath the South Western Cameroon, from Gravity Data Analysis  [PDF]
Marcel Jean, E. J. M. Abate, P. Njandjock Nouck, H. E. Ngatchou, V. Oyoa, C. T. Tabod, E. Manguelle-Dicoum
International Journal of Geosciences (IJG) , 2016, DOI: 10.4236/ijg.2016.78075
Abstract: 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. Theresultsshow 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.
Geophysical Contribution for the Determination of Aquifer Properties in Memve Ele, South Cameroon  [PDF]
Harlin L. E. Nkoungou, Philippe N. Nouck, Dieudonné Bisso, Stéphane Assembe, Eliézer M. Dicoum
Journal of Water Resource and Protection (JWARP) , 2012, DOI: 10.4236/jwarp.2012.410104
Abstract: This article aims to localise aquifer and to estimate hydraulic parameters such as transmissivity and tranverse resistance in the Memve Ele dam site (26.35 km2) in South-Cameroon region, using audiomagnetotelluric (AMT) method. For this purpose, resistivity data are collected at twenty-two measurement stations distributed along two perpendicular profiles in the study area. The sounding curves of phase and impedance are modelled and interpreted. The geological models and geoelectrical sections are also provided. The transverse resistivity and transmissivity field maps are plotted. The audiomagnetotellurics insights have been compared with boreholes. All these results allow us to localise the area which may be suitable to set up monitoring wells.
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