Philippe Njandjock Nouck;

Impact of Uncontrolled Urbanisation on Potential Aquifer Zones

Linda Well Tamto Have, Marthe Mbond Ariane Gweth, Euloge Felix Kayo Pokam, Blaise Pascal Gounou Pokam, Ibrahim Mbouombouo Ngapouth, Nicolas Anicet Aben Ekok et 3 autre(s)

Preprints.org

With the increase in population in certain urban areas, resulting in the sometimes uncontrolled expansion of cities, the increase in water requirements and the multiplication of sources of groundwater pollution, it is very important to know the boundaries of even the most complex aquifers in the world in order not only to guarantee their sustainable use, but also to keep them at a safe distance from sources of pollution, especially anthropogenic. Many of the world's cities draw their water from great distances because the aquifers they contain were not identified and preserved at the time they were built and developed. Just as it can be difficult to know the geometry of pollution sources, it is equally complex to know the geometry of aquifers, especially in granitic or gneissic bedrock. This paper examines the impact of uncontrolled urbanisation on potential aquifers. To do this, it uses an approach that integrates field and remote sensing data in the Analytic Hierarchy Process (AHP) through Geographic Information Systems (GIS), combined with piezometry data used in a clusterisassion to delimit potentially aquiferous zones in an environment characterised by poorly controlled urban growth. This approach uses spatial representation to delimit potentially aquiferous zones in urban and peri-urban environments. Given the anarchic nature of certain urban developments, this work shows that several aquifers in many urban areas may still be threatened by anthropogenic pollution and deserve to be preserved. Furthermore, the preservation of these aquifers in urban and peri-urban areas seems to require more urgent and robust policies from both governments and development partners if they are to be preserved and used sustainably.

• #water resources management and optimization
• #aquifer
• #urbanization
• #geology

Modeling of Groundwater Potential Zones in Semi-Arid Areas Using UAV, GIS and Multi-Criteria Decision Making

Michel Constant Njock, Marthe Mbond Ariane Gweth, André Michel Pouth Nkoma, Jorelle Larissa Méli’i, Blaise Pascal Gounou Pokam, Serges Raoul Kouamou Njifen et 4 autre(s)

Preprints.org

Today, groundwater potential zones (GWPZ) modeling based on scientific principles and modern techniques is a major challenge for scientists around the world. This challenge is even greater in arid and semi-arid areas. Unmanned aerial vehicle (UAV), geographic information system (GIS) and multi-criteria decision making (MCDM) are modern techniques used in various fields of application, particularly in groundwater exploration. This study attempts to use a workflow for modeling the GWPZ using UAV technology, GIS and the MCDM in semi-arid zones. Aerial survey produced a high-resolution DEM of 4 cm. Six influencing factors, including elevation model, drainage density, lineament density, slope, flood zone and topographic wetness index were considered for the delineation of the GWPZ. Four classes of groundwater potential were identified, high (4.64%), moderate (23.74%), low (18.2%) and very low (53.42%). Three validation methods were used, namely, borehole yield data, receiver operating characteristic-area under the curve (ROC-AUC), and principal component analysis (PCA) and gave accuracies of 82.14%, 65.4% and 72.49%, respectively. These validation indicate satisfactory accuracy and justifies the effectiveness of the approach. The mapping of GWPZ in semi-arid zones are very essential for the availability, planning of water resources management and help in sustainable development.

• #groundwater and watershed analysis
• #flood risk assessment and management
• #automated road and building extraction
• #topographic wetness index

Modelling of Groundwater Potential Zones in Semi-Arid Areas Using Unmanned Aerial Vehicles, Geographic Information Systems, and Multi-Criteria Decision Making

Michel Constant Njock, Marthe Mbond Ariane Gweth, André Michel Pouth Nkoma, Jorelle Larissa Méli’i, Blaise Pascal Gounou Pokam, Serges Raoul Kouamou Njifen et 4 autre(s)

Hydrology

Nowadays, modelling groundwater potential zones (GWPZs) based on scientific principles and modern techniques is a major challenge for scientists around the world. This challenge is even greater in arid and semi-arid areas. Unmanned aerial vehicles (UAVs), geographic information systems (GISs), and multi-criteria decision making (MCDM) are modern techniques that have been applied in various fields, especially in groundwater exploration. This study attempts to apply a workflow for modelling the GWPZs using UAV technology, GIS, and MCDM in semi-arid areas. An aerial survey provided a high-resolution DEM of 4 cm. Six influencing factors, including elevation model, drainage density, lineament density, slope, flood zone, and topographic wetness index, were considered to delineate the GWPZs. Four classes of groundwater potential were identified, namely high (4.64%), moderate (23.74%), low (18.2%), and very low (53.42%). Three validation methods, namely borehole yield data, receiver operating characteristic area under the curve (ROC-AUC), and principal component analysis (PCA), were used and gave accuracies of 82.14%, 65.4%, and 72.49%, respectively. These validations indicate a satisfactory accuracy and justify the effectiveness of the approach. The mapping of GWPZs in semi-arid areas is very important for the availability and planning of water resources management and for sustainable development.

• #groundwater and watershed analysis
• #flood risk assessment and management
• #automated road and building extraction
• #arid

Remote Sensing and Gis- Based Using Frequency Ratio and Analytical Hierarchy Methods: Case of Yaounde in Cameroon

Adérou Nsounjoundi Mbouombouo, Ibrahim Mbouombouo Ngapouth, J. I., Sandra Céleste Tchato, Marthe Mbond Ariane Gweth, Mohamed Loukouman Mounpou et 3 autre(s)

SSRN Electronic Journal

• #remote sensing and land use
• #hierarchy
• #remote sensing
• #geography

Response of a Structure Isolated by a Couple System Consisting of a QZS and FPS Under Horizontal Ground Excitation

Richie Kevin Wouako Wouako, Sandra Céleste Tchato, Euloge Felix Kayo Pokam, Blaise Pascal Gounou Pokam, André Michel Pouth Nkoma, Eliézer Manguelle Dicoum et 1 autre(s)

Preprints.org

The study of vibration isolation devices has become an emerging area of research in view of the extensive damage to buildings caused by earthquakes. The ability to effectively isolate seismic vibrations and maintain the stability of a building is thus addressed in this paper, which evaluates the effect of horizontal ground excitation on the response of a structure isolated by a coupled isolation system consisting of a non-linear damper (QZS) and a friction pendulum system (FPS). A single-degree-of-freedom system was used to model structures whose bases are subjected to seismic excitation in order to assess the effectiveness of the QZS-FPS coupling in reducing the structural response. The results obtained revealed significant improvements in structural performance when the QZS-FPS uses a damper of optimum stiffness. A 30% reduction in displacement was recorded compared with the QZS for two signals, one harmonic and the other stochastic. In addition, the study demonstrated that the QZS-FPS combination can offer better control of building vibration in terms of horizontal displacements.

• #structural response to dynamic loads
• #geophysics and sensor technology
• #fluid dynamics simulations and interactions
• #excitation

Response of a Structure Isolated by a Coupled System Consisting of a QZS and FPS Under Horizontal Ground Excitation

Richie Kevin Wouako Wouako, Sandra Céleste Tchato, Euloge Felix Kayo Pokam, Blaise Pascal Gounou Pokam, André Michel Pouth Nkoma, Eliézer Manguelle Dicoum et 1 autre(s)

Buildings

The study of vibration isolation devices has become an emerging area of research in view of the extensive damage to buildings caused by earthquakes. The ability to effectively isolate seismic vibrations and maintain the stability of a building is thus addressed in this paper, which evaluates the effect of horizontal ground excitation on the response of a structure isolated by a coupled isolation system consisting of a non-linear damper (QZS) and a friction pendulum system (FPS). A single-degree-of-freedom system was used to model structures whose bases are subjected to seismic excitation in order to assess the effectiveness of the QZS–FPS coupling in reducing the structural response. The results obtained revealed significant improvements in structural performance when the QZS–FPS system uses a damper of optimum stiffness. A 30% reduction in displacement was recorded compared with QZS alone for two signals, one harmonic and the other stochastic. The response of the QZS–FPS system with soft stiffness to a harmonic pulse reveals amplitudes reaching around eight times those of the pulse at low frequencies and approaching zero at high frequencies. In comparison, the rigid QZS–FPS coupling has amplitudes 0.9 and 3.5 times higher than those of the harmonic signal. Thus, the resonance amplitudes observed for the QZS–FPS system are lower than those reported in other studies. This analysis highlights the performance differences between the two types of stiffness in the face of harmonic pulses, underlining the importance of the choice of stiffness in vibration management applications. The stochastic results show that on both hard and soft soils, the new QZS–FPS system causes structures to vibrate horizontally with maximum amplitudes of the order of 0.003 m and 0.007 m respectively. So, QZS–FPS coupling can be more effective than all other isolators for horizontal ground excitation. In addition, the study demonstrated that the QZS–FPS combination can offer better control of building vibration in terms of horizontal displacements.

• #structural response to dynamic loads
• #seismic performance and analysis
• #structural health monitoring techniques
• #excitation

Techno-Economic Optimization of Hybrid Renewable Energy Systems (HRESs) and Feasibility Study on Replacing Diesel and Photovoltaic Systems with Hydrogen for Electrical and Small Deferrable Loads: Case Study of Cameroon

Tabitha Christie Vartan Messana M’oboun, Nasser Yimen, Jorelle Larissa Méli’i, André Michel Pouth Nkoma, Philippe Njandjock Nouck

Hydrogen

To reduce the amount of harmful gases produced by fossil fuels, more environmentally friendly and sustainable alternatives are being proposed around the world. As a result, technologies for manufacturing hydrogen fuel cells and producing green hydrogen are becoming more widespread, with an impact on energy production and environmental protection. In many countries around the world, and in Africa in particular, leaders, scientists, and populations are considering switching from fossil fuels to so-called green energies. Hydrogen is therefore an interesting alternative that deserves to be explored, especially since both rural and urban populations have shown an interest in using it in the near future, which would reduce pollution and the proliferation of greenhouse gases, thereby mitigating global warming. The aim of this paper is to determine the hybrid energy system best suited to addressing the energy problem in the study area, and then to make successive substitutions of different energy sources, starting with the most polluting, in order to assess the possibilities for transitioning the energy used in the area to green hydrogen. To this end, this study began with a technical and economic analysis which, based on climatic parameters, led to the proposal of a PV/DG-BATTery system configuration, with a Net Present Cost (NPC) of USD 19,267 and an average Cost Of Energy (COE) of USD 0.4, and with a high proportion of CO2 emissions compared with the PV/H2GEN-BATT and H2GEN systems. The results of replacing fossil fuel generators with hydrogen generators are beneficial in terms of environmental protection and lead to a reduction in energy-related expenses of around 2.1 times the cost of diesel and a reduction in mass of around 2.7 times the mass of diesel. The integration of H2GEN, at high duty percentages, increases the Cost Of Energy, whether in a hybrid PV/H2GEN system or an H2GEN system. This shows the interest in the study country in using favorable duty proportions to make the use of hydrogen profitable.

• #hybrid renewable energy systems
• #energy and environment impacts
• #electric vehicles and infrastructure
• #fossil fuel

Controlling Water Inflows and Optimizing Production from an Oil Well Using Chemical Injection

Isnella Maella Dago, Kasi Njeudjang, Hassan Ibrahim Abakar, Darel Fouazong Sontia, Noel Nyang Kibanya, Philippe Njandjock Nouck

Environmental and Earth Sciences Research Journal

The well called X (for confidential reasons) put into production in 2003 presents excessive water inflows a few years after it was put into production.The aim of this paper is to reduce this water flow through the chemical injection method.The available PVT, reservoir, and completion data are analyzed by using the nodal and sensitivity analysis methods.The results obtained show that initially the well X produced 509.1 STB/d of liquid, i.e. 71.3 STB/d of oil and 437.9 STB/d of water for a water cut of 86%.After flooding the tank with 80,000 ppm of polymers and 2,000 ppm of gels, the variation in viscosity followed by the decrease in oil saturation and the increase in water saturation will lead to a decrease in water cut (percentage of water production) up to 0%.This reduction in water cut is lighten the hydrostatic column so the liquid production rate is 2,572.5 STB/d of liquids, i.e. 2,058 STB/d of oil and 514.5 STB/d of water for a water cut of 20%.The economic report shows a minimum profit of $55,923,628 with a return on investment over a period of 1 month after the project is put into operation.

• #reservoir engineering and simulation methods
• #oil and gas production techniques
• #enhanced oil recovery techniques
• #production (economics)

Groundwater Potential and Flood Hazard Maps to Improve the Livelihood of Rural Communities of the Extreme Nord Region of Cameroon

Nicola Perilli, Marthe Mbond Ariane Gweth, Dario Leoni, Georges Nshagali Biringanine, Philippe Njandjock Nouck

Advances in Science, Technology & Innovation/Advances in science, technology & innovation

• #groundwater and watershed analysis
• #livelihood
• #groundwater
• #water resource management

Investigation of the recurrent flash flood events in the Far-North Region of Cameroon

Ernest Djomdi, Zakari Arétouyap, Dady Herman Agogue Feujio, Charles Ngog II Legrand, Cedric Nguimfack Nguimgo, Abas Ndinchout Kpoumie et 1 autre(s)

Earth Science Informatics

• #flood risk assessment and management
• #groundwater and watershed analysis
• #hydrology and watershed management studies
• #flash flood

Investigation of the recurrent flash flood events in the Far-North Region of Cameroon

Ernest Djomdi, Zakari Arétouyap, Dady Herman Agogue Feujio, Charles Ngog II Legrand, Cedric Nguimfack Nguimgo, Abas Ndinchout Kpoumie et 1 autre(s)

Research Square

• #flood risk assessment and management
• #hydrology and drought analysis
• #groundwater and watershed analysis
• #flash flood

Spatial Distribution and Characteristics of Lineaments Using Fractal and Multifractal Analysis for Evaluating the Structural Controls on a Regional-Scale Gold Mineralization, Cameroon, Central Africa

Salomon César Nguemhe Fils, Carrol Hedwige Bekele Mongo, Mumbfu Ernestine Mimba, Aristide Clement Charly Mboua, Jean Bassahak, Philippe Njandjock Nouck et 1 autre(s)

Journal of Geovisualization and Spatial Analysis

• #geochemistry and geologic mapping
• #soil geostatistics and mapping
• #geological and geochemical analysis
• #multifractal system

Sustainable management of drinking water quality in the locality of Massouro, Chad

Telesphore Djao, Diab Ahmad Diab, Aguiza Abaï Emmanuel, Charlene Claudia Manhouli Yorsam, Janvier Domra Kana, Philippe Njandjock Nouck

Discover Water

This study evaluates the quality of drinking groundwater in the city of Moussoro using geochemical, bacterial, and multivariate statistical methods. Access to safe drinking water is a major concern for the population in these regions, as the distribution of this resource is unequal across continents and is often affected by human activities, making it vulnerable. The analysis revealed two categories of water: potable and non-potable. The presence of pollutant indicators, such as Escherichia coli ( E. coli ) and total coliforms, was observed in most samples. This presence indicates water contamination and requiring monitoring and treatment before it is consumed by the population. Overall, most of the physicochemical parameters comply with the World Health Organisation guidelines for drinking water. However, the concentration of ammonium (NH4 + ) was high. Pollution elements such as ammonium (NH4 + ) and E . coli , indicate that human activities also contribute to water mineralisation. The study could ensure sustainable access to safe drinking water, thereby enhancing the overall quality of life in Moussoro.

• #child nutrition and water access
• #water management and technologies
• #medicinal plant studies
• #locality

Estimation of radiogenic heat production of the Adamawa region in Cameroon, Central Africa: an insight from spectral analysis of EMAG2 data

Kasi Njeudjang, Boris Merlain Djousse Kanouo, Apollinaire Bouba, Madeleine Nitcheu, William Assatsé Teikeu, Landry Soh Tamehe et 2 autre(s)

Arabian Journal of Geosciences

• #geophysical and geoelectrical methods
• #earthquake detection and analysis
• #geological and geophysical studies
• #radiogenic nuclide

High-precision structural mapping using advanced enhancement methods of gravity anomalies in Southwest Cameroon (Central Africa): tectonic implications

Willy Lemotio, Paul Gautier Kamto, Luan Thanh Pham, Franck Eitel Kemgang Ghomsi, Alex Onana Ntouda, Cyrille Armel Cheunteu Fantah et 2 autre(s)

Acta Geophysica

• #geophysical and geoelectrical methods
• #geophysics and gravity measurements
• #seismic imaging and inversion techniques
• #lineament

Multi-Stage Hydraulic Fracturing Completion Design Based on Ball-and-Sleeve Method

Kasi Njeudjang, Alain Amougou Zanga, Nasr Saeed, Théophile Ndougsa‐Mbarga, Philippe Njandjock Nouck

Iraqi Journal of Chemical and Petroleum Engineering

This paper proposes a completion that can allow fracturing four zones in a single trip in the well called “Y” (for confidential reasons) of the field named “X” (for confidential reasons). The steps to design a well completion for multiple fracturing are first to select the best completion method then the required equipment and the materials that it is made of. After that, the completion schematic must be drawn by using Power Draw in this case, and the summary installation procedures explained. The data used to design the completion are the well trajectory, the reservoir data (including temperature, pressure and fluid properties), the production and injection strategy. The results suggest that multi-stage hydraulic fracturing can be done in a single trip by using the ball-and-sleeve method. Metallurgy and hydrogenated nitrile are sealing elementary constituent of chromium which are essential materials found in alloy with 13% of chromium.

• #oil and gas production techniques
• #hydraulic fracturing and reservoir analysis
• #drilling and well engineering
• #completion (oil and gas wells)

Possible Influence of Brittle Tectonics on the Main Road Network Built in the Central African Environment

Sandra Céleste Tchato, Blaise Pascal Gounou Pokam, Marthe Mbond Ariane Gweth, Euloge Felix Kayo Pokam, Michel André Pouth Nkoma, Ibrahim Mboumbouo Ngapouth et 3 autre(s)

Preprints.org

The construction of sustainable road and highway networks in the world, despite numerous feasibility, pre-feasibility and execution studies, are always confronted with the demands and vagaries of foreseeable and unforeseeable natural disasters. Studying cyclones, earthquakes, fracturing and landslide zones along roads is therefore a challenge for the sustainability of these infrastructures. In many countries around the world, the methods generally used for these studies are not only expensive and time-consuming, but the results obtained are not always efficient. This work examines whether Landsat 8 (with a high cloud level) and SRTM data can be used in both equatorial and coastal Central Africa zones to produce relevant mapping, locating fracture and landslide zones, in order to contribute not only to better road layout at lower cost and in a relatively short time, but also to better prevention of geological disasters that may occur on its network. To this end, a map of the main road network was produced and validated with field data, as well as the maps of the main unstable slopes, faults and fractures zones intersecting the road or highway network. These approaches are useful for sustainable planning, management, monitoring and extension of roads worldwide especially, in Central Africa.

• #landslides and related hazards
• #geographic information systems studies
• #landslide
• #work (physics)

Possible Influence of Brittle Tectonics on the Main Road Network Built in the Central African Environment Using Remote Sensing and GIS

Sandra Céleste Tchato, Blaise Pascal Gounou Pokam, Marthe Mbond Ariane Gweth, Euloge Felix Kayo Pokam, André Michel Pouth Nkoma, Ibrahim Mbouombouo Ngapouth et 3 autre(s)

Sustainability

The construction of sustainable road and highway networks in the world, despite numerous feasibility, pre-feasibility and execution studies, are always confronted with the demands and vagaries of foreseeable and unforeseeable natural disasters. Studying cyclones, earthquakes, fracturing and landslide zones along roads is therefore a challenge for the sustainability of these infrastructures. In many countries around the world, the methods generally used for these studies are not only expensive and time-consuming, but also the results obtained are not always efficient. This work examines whether Landsat 8 (with a high cloud level) and SRTM data can be used in both equatorial and coastal Central Africa zones to produce relevant mapping, locating fracture and landslide zones, in order to contribute not only to a better road layout at lower cost and in a relatively short time, but also to a better prevention of geological disasters that may occur on its network. To this end, a map of the main road network was produced and validated with field data, as well as the maps of the main unstable slopes, faults and fractures zones intersecting the road or highway network. These approaches are useful for sustainable planning, management, monitoring and extension of roads worldwide, especially in Central Africa.

• #geochemistry and geologic mapping
• #groundwater and watershed analysis
• #landslides and related hazards
• #landslide

Analysis of safety factors for roads slopes in central Africa

Ibrahim Mbouombouo Ngapouth, Jorelle Larissa Méli’i, Marthe Mbond Ariane Gweth, Blaise Pascal Gounou Pokam, Yvonne Poufone Koffi, Michel Constant Njock et 2 autre(s)

Engineering Failure Analysis

• #landslides and related hazards
• #geotechnical engineering and analysis
• #rock mechanics and modeling
• #gneiss

Crustal Thickness Variations and Tectonic Settings in the Southwest Cameroon Inferred from Gravity and Topography Data

Willy Lemotio, Ngatchou Evariste, Adiang M. Cyrille, Alain-Pierre K. Tokam, Sévérin Nguiya, Philippe Njandjock Nouck

Lithosphere

Abstract EIGEN 6C4 gravity anomalies are interpreted to determine the lateral and vertical variations in the crust and upper mantle structure and their influence on the isostasy of the coastal plain, transition zone between the Congo Craton (CC), the Pan-African Belt (PAB), and adjacent areas. The regional gravity anomalies have been inverted in an attempt to provide a Moho depth map. The inversion process was based on the Parker-Oldenburg method with a density contrast of 0.55 g/cm3 and an average depth reference of 39 km. In addition, various tests have been performed to validate the resulting Moho model and estimate the efficiency of the 3D gravity inversion by varying the density contrast for a fixed Moho reference depth. Inversion results reveal that the Moho depths generally agree with those obtained from previous geophysical studies. The computation of the isostatic models using the ETOPO1 digital elevation model (DEM) and its comparison with the Moho models obtained from gravity induce the following main conclusions: (1) an overcompensated crust beneath the coastal plain and the Yaounde Domain, (2) the crust beneath areas located in the southern end of the Adamawa-Yade Domain is thin and undercompensated, and (3) main volcanoes of the Southwestern Cameroon Volcanic Line (CVL) are isostatically undercompensated. This study also revealed that the local isostatic compensation law is not satisfied for most of the tectonic provinces of the study area, and we suggest alternative tectonic mechanisms to support topography below these tectonic features. Additionally, most seismic events (M>3.5) occurred in areas marked by abrupt changes in compensation amplitude. Thus, we concluded from this study that the northern limit of the CC, the Mount Cameroon, and its surroundings are tectonic extension areas that may play a crucial role in the occurrence of future earthquakes.

• #geophysical and geoelectrical methods
• #geophysics and gravity measurements
• #seismic imaging and inversion techniques
• #geology

Geophysical investigation of hydrocarbon in the southern part of Douala Kribi Campo basin, Cameroon

Janvier Domra Kana, Jonathan Anaïdan Tanembe, Diab Ahmad Diab, Franck Eitel Kemgang Ghomsi, Zakari Arétouyap, Serge Mbida et 2 autre(s)

Journal of African Earth Sciences

• #hydrocarbon exploration and reservoir analysis
• #seismic imaging and inversion techniques
• #geological and geophysical studies
• #petrophysics

Groundwater Potential index map and characterization of unconfined aquifers, in crystalline basement region of Cameroon, using Multicriteria Decision Making

Georges Nshagali Biringanine, Jorelle Larissa Méli’i, Rachel Ngo Nyouma, Jean Marcel, Valentin Oyoa, Nicola Perilli et 1 autre(s)

Arabian Journal of Geosciences

• #groundwater and watershed analysis
• #geochemistry and geologic mapping
• #groundwater and isotope geochemistry
• #groundwater recharge

Possible pathways of seawater intrusion along the Mount- Cameroon coastal area using remote sensing and GIS techniques

Yvonne Poufone Koffi, Jorelle Larissa Méli’i, Zakari Arétouyap, Marthe Mbond Ariane Gweth, Salomon César Nguemhe Fils, Georges Nshagali Biringanine et 3 autre(s)

Advances in Space Research

• #groundwater and watershed analysis
• #hydrocarbon exploration and reservoir analysis
• #groundwater and isotope geochemistry
• #lineament

DELINEATION OF LINEAMENTS IN THE REGION OF OUADDAI (CHAD) USING GRAVITY DATA

Ecole Normale Superieure de NDjamena B.P. 460 NDjamena - Tchad., Diab Ahmad Diab, Philippe Njandjock Nouck, Ecole Normale Superieure de NDjamena B.P. 460 NDjamena - Tchad., Boukar Abdelhakim, Ecole Normale Superieure de NDjamena B.P. 460 NDjamena - Tchad. et 6 autre(s)

International Journal of Advanced Research

The gravity map of Ouaddai in the eastern region of Chad exhibits important anomalies that are often delimitated by the high gravity gradients, resulting from the density contrasts between various anomaly sources. This presumes an important tectonic activity in zone. Because of its arid and desert nature, the region is water-poor or even lacking water resources. The main source of water in the region is made of very deep aquifers. The gravity analysis from this study helps to better understand the network of faults in the area. Many complementary approaches of the gravity data processing have been applied, namely the horizontal gradient coupled to the upward and downward continuation and the Euler method. Results from the data filtring have allowed highlighting faults network in various directions (SSW-NNE S-N E-W, NE-SW) and the main direction. In total, 37 major faults were detected with various lengths including 11 (F6, F9, F10, F12, F17, F29, F31, F34, F35, F37) for a cumulative total length of 353 km oriented towards Bongor basin and 15 others (F1, F4, F7, F8, F11, F13, F18, F20, F23, F25, F26, F27, F28, F30, F33), for a cumulative total length of 621 km, oriented towards Doba basin. These faults are of paramount importance with great potential impacts on the regions hydrocarbon reservoirs. Thise results in one hand confirmed some known faults from the previous investigations. In the other hand, the study helps to identify other new and unknown tectonic signatures.

• #geophysics and gravity measurements
• #geomagnetism and paleomagnetism studies
• #statistical and numerical algorithms
• #lineament

Fracture network mapping using remote sensing in three crater lakes environments of the Cameroon volcanic line (central Africa)

Marthe Mbond Ariane Gweth, Jorelle Larissa Méli’i, Valentin Oyoa, Diab Ahmad Diab, Daniel Hervé Gouet, Jean Marcel et 1 autre(s)

Arabian Journal of Geosciences

• #geological and geophysical studies
• #earthquake and tectonic studies
• #hydrocarbon exploration and reservoir analysis
• #impact crater

Fractures models comparison using GIS data around crater lakes in Cameroon volcanic line environment

Marthe Mbond Ariane Gweth, Harlin Ekoro Nkoungou, Jorelle Larissa Méli’i, Daniel Hervé Gouet, Philippe Njandjock Nouck

The Egyptian Journal of Remote Sensing and Space Science

This study assesses the contribution of Landsat 7 ETM + and Landsat 8 OLI images to observe existing fractures and faults of at least 12 km in length around the lakes Nyos, Monoun and Oku whose are three major crater lakes in the Cameroon Volcanic Line (CVL) environment. The results obtained using principal component analysis, directional filters and linear densities show many similarities and some differences. In fact, Landsat 7 ETM+ and Landsat 8 OLI images present 427 lineaments in common, including all known geological linear structures, certain geophysical lineaments and some new fractures. This proves that the area is much more fractured than previously known and that only the environments of lakes Nyos and Monoun are crossed by faults and fractures. Apart from the similarities, the differences observed relate to the lineaments specific to each image, their main direction, their length and the values ​​of the fracturing densities. Also, the results show that the Landsat 7 ETM+ and Landsat 8 OLI images are suitable for the structural research in the CVL environment. But, the Landsat 8 OLI images are more efficient as they have made it possible to reconstitute almost all known geological structures and their lengths.

• #geochemistry and geologic mapping
• #groundwater and watershed analysis
• #hydrocarbon exploration and reservoir analysis
• #lineament

GIS based exploring of low-enthalpy geo-energy potentials in the Subsaharan area in Central Africa

Janvier Domra Kana, Noël Djongyang, Zakari Arétouyap, Kasi Njeudjang, Danwé Raïdandi, Philippe Njandjock Nouck et 2 autre(s)

Geomechanics and Geophysics for Geo-Energy and Geo-Resources

• #geothermal energy systems and applications
• #geophysical and geoelectrical methods
• #geophysics and gravity measurements
• #geography

Influence of natural discontinuities and mechanical properties on the fragmentation of marble by blasting in Central Africa

Michel Constant Njock, Jorelle Larissa Méli’i, Yvonne Koffi Poufonne, Ibrahim Ngapouth Mbouombouo, Tamto Have Linda Well, Zakari Arétouyap et 2 autre(s)

Environmental Earth Sciences

• #rock mechanics and modeling
• #earthquake and tectonic studies
• #landslides and related hazards
• #classification of discontinuities

Magnetotelluric Evaluation of the Pan African Belt and Oceanic Crust Incidence on the Congo Craton

H. L. Ekoro Nkoungou, Jorelle Larissa Méli’i, Daniel Hervé Gouet, V. Oyoa, Philippe Njandjock Nouck, Eliézer Manguelle Dicoum

Geosciences

The both influence of the Oceanic crust and the pan-African belt on the northern limit of the Congo Craton, made up of the Ntem, Lower Nyong and Ayina units, remains partially described. To do this, the magnetotelluric method which were used for good modeling the southern limit of this Craton, was also deployed through 22 stations distributed over its 3 units. The data process by cascade decimation with a dimensional analysis by the phase of this tensor, allowed to detect a major network of regional faults defining the course of Ntem rivers, highlight the violence of tectonic activity during Eburnean erosion in the Ntem unit, through the undulations of the gneiss-granite. Ripples were also observed in the lower Nyong unit in the geoelectric section, however the dimensional analysis could not confirm them as well as the observation of the resistivity curves according to the two modes, thus showing an anomaly attributable to the mobile zone adjacent to the lower Nyong unit. The depth of the upper limit of the Craton materialized by the granite shield was recorded at 3 km in the unit of the lower Nyong, 3.5 km in the unit of Ayina and 1.5 km in the unit of Ntem, moreover, no major fault has been highlighted in the Ayina and lower Nyong units while a network of major faults defining the course of the Ntem river has been highlighted. These different results have led us to the conclusion of the predominance of the activity of the pan african Mobile belt on the northern limit of the Congo Craton.

• #geophysical and geoelectrical methods
• #geophysical methods and applications
• #seismic waves and analysis
• #craton

Typology of Sounding Curves and Lithological 1D Models of Mineral Prospecting and Groundwater Survey within Crystalline Basement Rocks in the East of Cameroon (Central Africa) Using Electrical Resistivity Method and Koefoed Computation Method

Daniel Hervé Gouet, Arsène Meying, H. L. Ekoro Nkoungou, Stéphane Patrick Assembe, Philippe Njandjock Nouck, Théophile Ndougsa Mbarga

International Journal of Geophysics

Resistivity method using seventy-sixth (976) Schlumberger vertical electrical soundings along forty-one (41) profiles are conducted in the Batouri and Ngoura subdivisions, East region of Cameroon, to investigate the subsurface layering, mineral potential, and groundwater resource characteristics. Results of quantitative and qualitative interpretation of data using Koefoed computation method reveal two to five layers having geometrical and electrical characteristics of geological layer models: topsoil (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn>0.5</mml:mn><mml:mtext> </mml:mtext><mml:mtext>m</mml:mtext><mml:mo>&lt;</mml:mo><mml:msub><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msub><mml:mo>&lt;</mml:mo><mml:mn>3</mml:mn><mml:mtext> </mml:mtext><mml:mtext>m</mml:mtext></mml:math>; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mn>600</mml:mn><mml:mo>&lt;</mml:mo><mml:mi>ρ</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>3000</mml:mn><mml:mtext> </mml:mtext><mml:mi>Ω</mml:mi><mml:mo>.</mml:mo><mml:mtext>m</mml:mtext></mml:math>), lateritic soils (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mn>3</mml:mn><mml:mo>&lt;</mml:mo><mml:msub><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msub><mml:mo>&lt;</mml:mo><mml:mn>20</mml:mn><mml:mtext> </mml:mtext><mml:mtext>m</mml:mtext></mml:math>; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mn>1000</mml:mn><mml:mo>&lt;</mml:mo><mml:mi>ρ</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>4000</mml:mn><mml:mtext> </mml:mtext><mml:mi>Ω</mml:mi><mml:mo>.</mml:mo><mml:mtext>m</mml:mtext></mml:math>); conductive layer (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mn>5</mml:mn><mml:mo>&lt;</mml:mo><mml:msub><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msub><mml:mo>&lt;</mml:mo><mml:mn>110</mml:mn><mml:mtext> </mml:mtext><mml:mtext>m</mml:mtext></mml:math>; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mn>100</mml:mn><mml:mo>&lt;</mml:mo><mml:mi>ρ</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>1000</mml:mn><mml:mtext> </mml:mtext><mml:mi>Ω</mml:mi><mml:mo>.</mml:mo><mml:mtext>m</mml:mtext></mml:math>); fractured/weathered granite (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mn>20</mml:mn><mml:mo>&lt;</mml:mo><mml:msub><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msub><mml:mo>&lt;</mml:mo><mml:mn>60</mml:mn><mml:mtext> </mml:mtext><mml:mtext>m</mml:mtext></mml:math>; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><mml:mn>1000</mml:mn><mml:mo>/</mml:mo><mml:mn>5000</mml:mn><mml:mo>&lt;</mml:mo><mml:mi>ρ</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>3000</mml:mn><mml:mo>/</mml:mo><mml:mn>9000</mml:mn><mml:mtext> </mml:mtext><mml:mi>Ω</mml:mi><mml:mo>.</mml:mo><mml:mtext>m</mml:mtext></mml:math>); clayey layer (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M9"><mml:mn>5</mml:mn><mml:mo>&lt;</mml:mo><mml:msub><mml:mrow><mml:mi>e</mml:mi></mml:mrow><mml:mrow><mml:mi>p</mml:mi></mml:mrow></mml:msub><mml:mo>&lt;</mml:mo><mml:mn>20</mml:mn><mml:mtext> </mml:mtext><mml:mtext>m</mml:mtext></mml:math>; <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M10"><mml:mn>600</mml:mn><mml:mo>/</mml:mo><mml:mn>1500</mml:mn><mml:mo>&lt;</mml:mo><mml:mi>ρ</mml:mi><mml:mo>&lt;</mml:mo><mml:mn>2000</mml:mn><mml:mo>/</mml:mo><mml:mn>3500</mml:mn></mml:math> (dry) Ω .m); and fresh granites (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M11"><mml:mi>ρ</mml:mi><mml:mo>&gt;</mml:mo><mml:mn>4000</mml:mn><mml:mtext> </mml:mtext><mml:mi>Ω</mml:mi><mml:mo>.</mml:mo><mml:mtext>m</mml:mtext></mml:math>). From the qualitative interpretation of VES curves, the subsurface layering is depicted by nine (09) types of sounding curves (G, H, A, QH, KH, HK, HA, HKH, and KHK) characterizing the vertical changes and the typology of sounding curves in the East Cameroon crystalline basements. The lithology of the subsurface is dominated (more than 80%) by geoelectrical and lithological 1D models derived by the H, QH, KH, HK, HA, HKH, and KHK curve types. These models are characterized by the presence of conductive layers and fractured/weathered granites derived from tectonic activities of the region. Also, the resistivity method (VES) applied in this study bring information about variation of the resistivity with depth, geological structures, fractures, and rupture zones in the underground until 120 m depth. These abovementioned information reveal proper hydrogeological and mining conditions for an efficient evaluation of the mineral potential and groundwater resources.

• #geophysical and geoelectrical methods
• #geochemistry and geologic mapping
• #seismic imaging and inversion techniques
• #geology

A Coupled Hydrogeophysical Approach to Enhance Groundwater Resources Management in Developing Countries

Zakari Arétouyap, Dieudonné Bisso, Philippe Njandjock Nouck, Jamal Asfahani

Advances in Science, Technology & Innovation/Advances in science, technology & innovation

• #geophysical and geoelectrical methods
• #groundwater flow and contamination studies
• #water systems and optimization
• #aquifer

Hydraulic parameters evaluation of the Pan-African aquifer by applying an alternative geoelectrical approach based on vertical electrical soundings

Zakari Arétouyap, Dieudonné Bisso, Jorelle Larissa Méli’i, Philippe Njandjock Nouck, André Njoya, Jamal Asfahani

Geofísica Internacional

The present article aims at determining hydraulic parameters of the Pan-African aquifer in the region of Adamawa-Cameroon, namely the transmissivity (T) and the hydraulic conductivity (K). For this, fifty vertical electrical soundings (VESs),including 14 performed near existing boreholes with known values of water resistivity, have been conducted in the region using the Terrameter ABEMSAS-1000 with a spacing of current electrodes (AB) varying from 2 to 600 m.The curve matching technique is used to set structural parameters then, an inverse technique algorithm fits both theoretical and field curves for each experimental. The transverse resistance TR and the transmissivity T for the interpreted 14 VES are computed, then used to establish two relationships: one between the modified transverse resistance (MTR) andthe transverse resistance (TR) and another between MTR and the transmissivity (T).This enabled to compute MTR (ranged from 1526 to 28209 ?.m² with an average of 7873 ?.m²),TR (ranged from 24 to 31350 ?.m² with an average of 7476 ?.m²), T (ranged from 4 to 17.4 m²/day with an average of 7.23 m²/day) and K (ranged from 0.07 to 0.74 m/day with an average of 0.31 m/day) values in the whole region. The approach used for this purpose is effective and exportable to other Pan-African regions in the world.

• #geophysical and geoelectrical methods
• #geophysical methods and applications
• #geotechnical and construction materials studies
• #aquifer

Hydrogeophysical Characteristics of Pan-African Aquifer Specified Through an Alternative Approach Based on the Interpretation of Vertical Electrical Sounding Data in the Adamawa Region, Central Africa

Zakari Arétouyap, Dieudonné Bisso, Philippe Njandjock Nouck, L. E. Amougou Menkpa, Jamal Asfahani

Natural Resources Research

• #geophysical and geoelectrical methods
• #groundwater flow and contamination studies
• #geophysical methods and applications
• #vertical electrical sounding

Radarsat-1 image processing for regional-scale geological mapping with mining vocation under dense vegetation and equatorial climate environment, Southwestern Cameroon

Salomon César Nguemhe Fils, Carrol Hedwige Bekele Mongo, David Guimolaire Nkouathio, Mumbfu Ernestine Mimba, Joachim Etouna, Philippe Njandjock Nouck et 1 autre(s)

The Egyptian Journal of Remote Sensing and Space Science

The potential of Radarsat-1 beam mode Synthetic Aperture Radar (SAR) data processing for geological investigation in an equatorial environment has been evaluated. This approach used textural analysis based on Grey Level Co-occurrence Matrix (GLCM) on our image, followed by Principal Component Analysis (PCA) performed on eight normalized co-occurrence indices created (mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment and correlation) and directional filters for lithological discriminations and lineament investigations. Red-Green-Blue (RGB) color-composite was applied to three of the indices, the mean, variance and homogeneity, highlighting the morphostructure of the study area and facilitate lithology discrimination. The PC1 band was multiplied by itself (as PC1 × PC1 image) to enhance the information contained in this neo-canal and to reduce noise during filtering. Directional filters were then applied to the PC1 × PC1 image at 0°, 45°, 90° and 135° directions and the structure lines were extracted manually in a GIS software. From the results obtained, color-composite produced image map containing lithological units easily identified formations such as continental and coastal deposits, sedimentary stack, micaschists, garnet micaschists, micaceous quartzites, charnockitic orthogneisses, and coincided with those already existing on published geological map from Maurizot et al. (1986) and non-published geological map after IRGM geological field campaign. A total of 572 lineaments features (fractures and major faults) were identified on the filtered images and mapped. Major structures (faults) were considered as those clearly identified in the four directions while minor structures (fractures) were those observed in at least two directions. They are oriented in one of the two main directions: NE-SW (N040–N060) and NNW-SSE (N345–N360). The lineament result showed those that already existed on the reference maps and the newly updated lineaments. Spatial relationships between mapped lineaments and areas of current and historical mining exploration were examined by overall lineament density. GPS points of gold indices existing in the area correlate with areas of high lineament density particularly around the Ngovayang massif within the Paleoproterozoic Nyong unit. This study stresses the usefulness of remote sensing data and methods in field campaign, improvement of published geological maps and mining prospecting in areas with an equatorial climate.

• #geochemistry and geologic mapping
• #remote-sensing image classification
• #soil geostatistics and mapping
• #lineament

Validation of gravity data from the geopotential field model for subsurface investigation of the Cameroon Volcanic Line (Western Africa)

Jean Marcel, Jean Marcel Abaté Essi, Philippe Njandjock Nouck, Oumarou Sanda, Eliézer Manguelle-Dicoum

Earth Planets and Space

Belonging to the Cameroon Volcanic Line (CVL), the western part of Cameroon is an active volcanic zone with volcanic eruptions and deadly gas emissions. The volcanic flows generally cover areas and bury structural features like faults. Terrestrial gravity surveys can hardly cover entirely this mountainous area due to difficult accessibility. The present work aims to evaluate gravity data derived from the geopotential field model, EGM2008 to investigate the subsurface of the CVL. The methodology involves upward continuation, horizontal gradient, maxima of horizontal gradient–upward continuation combination and Euler deconvolution techniques. The lineaments map inferred from this geopotential field model confirms several known lineaments and reveals new ones covered by lava flows. The known lineaments are interpreted as faults or geological contacts such as the Foumban fault and the Pan-African Belt–Congo craton contact. The lineaments highlighted coupled with the numerous maar lakes identified in this volcanic sector attest of the vulnerability of the CVL where special attention should be given for geohazard prevention.

• #geophysical and geoelectrical methods
• #geophysics and gravity measurements
• #geological and geophysical studies
• #geology

Variation of Subsurface Resistivity in the Pan-African Belt of Central Africa

Dieudonné Bisso, Zakari Arétouyap, Georges Nshagali Biringanine, Philippe Njandjock Nouck, Jamal Asfahani

Advances in Science, Technology & Innovation/Advances in science, technology & innovation

• #geophysical and geoelectrical methods
• #seismic imaging and inversion techniques
• #seismic waves and analysis
• #geology

Hydrogeological activity of lineaments in Yaoundé Cameroon region using remote sensing and GIS techniques

William Teikeu Assatsé, Philippe Njandjock Nouck, Charles T. Tabod, Joseph Martial Akame, Georges Nshagali Biringanine

The Egyptian Journal of Remote Sensing and Space Science

Though Yaoundé zone is characterized by abundant rains, access to safe drinking water becomes a difficult activity, because of climate change and pollution caused by human activities. Lineament zones on the earth’s surface are important elements in understanding the dynamics of the subsurface fluid flow. However, good exposures of these features are always lacking in some areas around Yaoundé, characterized by thick alteration. During field surveys these conditions, in many cases, hinder the proper characterization of such features. Therefore, an approach that identifies the regional lineaments on remote-sensing images (Landsat Thematic Mapper and shaded digital terrain models), with its large scale synoptic coverage, could be promising. This paper aims to the structural organization of lineament network in the crystalline basement of Yaoundé from remote sensing data and characterize them by statistical and geostatistical techniques. The results were validated on the basis of the geological maps, the hydrogeological maps and the outcrop data. Statistical analysis of the lineaments network shows a distribution along the N0–10, N20–30, N40–60 and N140–150. The correlation between the productivity of high yield wells and the closest lineament confirms that these lineaments are surface traces of regional discontinuities and act as main groundwater flow paths.

• #groundwater and watershed analysis
• #hydrology and watershed management studies
• #flood risk assessment and management
• #lineament

Lessening the adverse effect of the semivariogram model selection on an interpolative survey using kriging technique

Zakari Arétouyap, Philippe Njandjock Nouck, Robert Nouayou, Franck Eithel Ghomsi Kemgang, Axel Dorian Piépi Toko, Jamal Asfahani

SpringerPlus

OBJECTIVE: Many parameters in environmental, scientific and human sciences investigations need to be interpolated. Geostatistics, with its structural analysis step, is widely used for this purpose. This precious step that evaluates data correlation and dependency is performed thanks to semivariogram. However, an incorrect choice of a semivariogram model can skew all the prediction results. The main objectives of this paper are (1) to simply illustrate the influence of the choice of an inappropriate semivariogram model and (2) to show how a best-fitted model can be selected. This may lessen the adverse effect of the semivariogram model selection on an interpolation survey using kriging technique. METHODS: The influence of the semivariogram model selection is highlighted and illustrated by thematic maps drawn using four different models (Gaussian, magnetic, spherical and exponential). Then, a guideline to select the most suitable model, using mean error (ME), mean square error (MSE), root mean square error (RMSE), average standard error (ASE), and root mean square standardized error (RMSSE), is proposed. RESULTS: The choice of a semivariogram model seriously influences the results of a kriging survey at both endpoints and amplitude of the range of the estimated values. However, the direction of variation of the interpolated values is independent of the semivariogram model: different semivariogram models (with the same characteristics) produce different thematic maps but, the areas of minimum and maximum values remain unchanged. Yet, the suitable model can be selected by means of ME, MSE, RMSE, ASE and RMSSE. CONCLUSION: The present article illustrates how the use of an inappropriate semivariogram model can seriously distort the results of an evaluation, assessment or prediction survey. To avoid such an inconveniency, a methodical approach based on the computation and analysis of ME, RMSE, ASE, RMSSE and MSE is proposed.

• #soil geostatistics and mapping
• #spatial and panel data analysis
• #advanced statistical methods and models
• #variogram

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

Marcel Jean, E. J. M. Abate, Philippe Njandjock Nouck, H. E. Ngatchou, V. Oyoa, Charles T. Tabod et 1 autre(s)

International Journal of Geosciences

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.

• #geophysics and gravity measurements
• #geophysical and geoelectrical methods
• #seismic imaging and inversion techniques
• #geology

Geophysical investigation of low enthalpy geothermal potential and ground water reservoirs in the Sudano-Sahelian region of Cameroon

Janvier Domra Kana, Noël Djongyang, Danwé Raïdandi, Philippe Njandjock Nouck, Robert Nouayou, Tabod Charles Tabod et 1 autre(s)

Journal of African Earth Sciences

• #geophysical and geoelectrical methods
• #geophysical methods and applications
• #seismic waves and analysis
• #geothermal gradient

Water Infiltration Study from Magnetotelluric Data in the Limestone Fault Network of Mintom (South Cameroon)

H. L. Ekoro Nkoungou, Daniel Hervé Gouet, Philippe Njandjock Nouck, Eliézer Manguelle Dicoum

International Journal of Geosciences

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.

• #geophysical and geoelectrical methods
• #geophysical methods and applications
• #geological and geophysical studies
• #magnetotellurics

Electrical and Geological Investigations to Conduct Petrophysical Study in Douala-Cameroon Sedimentary Basin

Philippe Njandjock Nouck, Dieudonné Miyem, Aristide Binyam-bi-Mpeck, Quentin Yene Atangana, Simon Ngos

Open Journal of Geology

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.

• #geophysical and geoelectrical methods
• #nmr spectroscopy and applications
• #geological and geophysical studies
• #geology

Geoelectrical prospection of aquifers in Eseka region, Center-Cameroon

Philippe Njandjock Nouck, Mbida Yem Atangana, Leonel Amougou, Pius Lissom, Mbida Yem

Journal of Emerging Trends in Engineering and Applied Sciences

This geophysical study was carried out in the city of Eseka, the head quarter of Nyong and Kelle Division, Center Region of Cameroon. It had as aims to prospect aquifers and to propose models of geophysical structures of the underground basement in the city. To this effect, the geophysical method of electrical resistivity was chosen, due to the local geologic context, and its easy application. With the aid of a resistivitimeter of mark TERRAMETER ABEM SAS 300, twenty (20) electrical soundings were effectuated in different points in the city. The treatment of data was done through several interpretation software, such as Geo-Elect. Mod and surfer8.0. Qualitative and quantitative interpretations, coupled with field and laboratory observations, permitted: the characterization of the lateritic crust constituted of the model of the terrain, into four and five layers of distinct terrain by their resistivity and thicknesses; the definition of the average depth of the upper aquifer from about three (03) meter in the loose clayey level, and the lower aquifer at about thirty (30) meter in the weathering and fractured gneiss level; the localization of the zone of conduction and resistant anomaly, at chosen depths in the study area. These results are important in future modeling process of the aquifers in this area.

• #geophysical and geoelectrical methods
• #geophysical methods and applications
• #geotechnical and construction materials studies
• #aquifer