Prehliadanie podľa Autor "Abdelrahman, Kamal"

Teraz sa zobrazuje 1 - 5 z 5
  • Obrázok miniatúry
    Položka
    Deciphering aeromagnetic data for sustainable sedimentary and structural insights in Obudu Plateau, Ikom Mamfe embayment and Oban Massif, southeastern Nigeria
    (Nature Publishing Group : London, 2025) Eze, Ohara E.; Ekwok, Stephen Eguba; Thompson, Cherish E.; Odey, Eunice Irmia; Okiwelu, Anthony A.; Abdelrahman, Kamal; Fnais, Mohammed S.; Andráš, Peter; Eldosouky, Ahmed Mohammed
    Aeromagnetic data acquired over the Obudu Plateau, Ikom Mamfe embayment, and Oban Massif was analyzed to evaluate the study area’s structural pattern and sedimentary thickness. Data filtering and other enhancement methods with 2-D forward modeling were applied to total magnetic intensity (TMI) data to evaluate the structural pattern, possible mineralization potential, sedimentary thickness, and basement framework disparity. To achieve this aim, several data enhancement techniques such as first vertical derivative (FVD), second vertical derivative (SVD), total horizontal derivative (THD), tilt angle derivative (TAD), analytic signal (AS), upward continuation (UC), low pass filter (LPF), high pass filter (HPF), Centre for Exploration Targeting (CET) and 2-D forward modeling were performed on the TMI data from which the buried subsurface structural lineaments and trends were unraveled. The structural lineaments delineated from the various enhancement operations revealed the major structural orientations of NE-SW. In contrast, the minor geologic structures trend in NNE-SSW, NW-SE, N-S, and E-W directions. These high frequency magnetic anomalies (geologic structures) are caused by post-depositional magmatic intrusions occurring at shallow depth and they have significant control over mineralization. They serve as migration pathways for hydrothermal fluids and accumulation zones for minerals. The depth estimation techniques like source parameter imaging (SPI), standard Euler deconvolution (SED) and 2D forward modelling employed in this study, revealed predominantly shallow depths (< 1400 m). These thin sedimentations are attributed to the widespread presence of Precambrian basement rocks in the Oban Massif and Obudu Plateau as well as the significant basaltic intrusions of Ikom-Mamfe Embayment. Furthermore, the 2-D forward model along the SW-NE profile revealed sediment thickness of 0–700 m overlying intruded metamorphic basement with magnetic susceptibility values ranging from 0.00001 to 0.00625 SI. The model which is highly undulant, revealed two sub-basins separated by the magmatic intrusion.
  • Obrázok miniatúry
    Položka
    Mapping landslide susceptibility and risk assessment on fragile ecosystem of Himalayan River basins
    (Taylor & Francis : Philadelphia, 2025) Khan, Zainab; Nawazuzzoha, Md; Abdelrahman, Kamal; Ali Sk, Ajim; Fnais Mohammed, S.; Shamim Syed, Kausar; Ahmad, Ateeque; Andráš, Peter
    Landslides pose a significant threat in the Himalayan region due to complex geology, steep terrain, and diverse climatic conditions. This study addresses the need for a multi-dimensional approach by integrating Machine Learning with GIS to map landslide susceptibility across Himalayan River basins. Conditioning variables including topographical, climatological, hydrological, and phenological factors, and surface conditions were analysed using SVM to predict landslide susceptibility. For validation, SHAP, ROC curves, and AUC were used. The model attained 87% accuracy. Risk assessment was performed by intersecting land use/land cover (LULC) data with susceptibility zones to quantify agricultural and Urban and Built-up land exposed to landslides, alongside zonal statistics to estimate population risks. The results indicate that 371.5 thousand hectares are at very high risk of landslides, and 209.2 thousand hectares are at high risk, with the Jhelum River Basin emerging as the most vulnerable in terms of population, agricultural land, and built-up areas. This study demonstrates the dominance of hydrological and vegetation-related variables, such as runoff and forest fires, in driving landslide susceptibility, as revealed by SHAP analysis. Integrating susceptibility models with risk assessment, the study provides insights for regional planning, disaster management, and policy-making, stressing targeted mitigation for vulnerable basins.
  • Obrázok miniatúry
    Položka
    Spatial analysis of leachate penetration at Lemna dumpsite, Calabar: Implications for sustainable waste management in Cross River State
    (Elsevier B.V. : Amsterdam, 2024) Igelle, Evaristus Idaga; Phil-Eze, Philip Ogbonnia; Akim, O. Okang; Kanu, H. Izuakolam; Ekwok, I. C.; Atsa, Joy William Undie; Ojugbo, P. A.; Okputu, Joseph S.; Abdelrahman, Kamal; Ekwok, Stephen Eguba; Andráš, Peter; Eldosouky, Ahmed Mohammed
    This study rigorously investigated the spatial analysis of leachate penetration at Lemna dumpsite, located in Calabar, Cross River State, Nigeria. Purposeful soil sampling, performed at specific intervals (5 m, 25 m, and 50 m) along the Electrical Resistivity profile line within the dumpsite, was augmented by water sample collection from five boreholes near Lemna dumpsite. Utilizing Electrical Resistivity Tomography (ERT) and Vertical Electric Sounding (VES) survey techniques, resistivity data were systematically gathered to comprehensively analyze the Leachate Penetration in the Lemna dumpsite. Laboratory analysis of soil and borehole water quality focused on Benzene, Toluene, Ethylbenzene, and Xylene (BTEX), with paired sample t-tests applied for statistical scrutiny. Analyzing the ERT and VES data employed sophisticated techniques embedded in Resistivity Two Dimension Invasion software and Advanced Geosciences Incorporation Earth Imager software. Substantial disparities (p < 0.05) emerged in the paired sample t-tests for BTEX in soil compared to National Environmental Standard Regulation and Enforcement Agency (NESREA) limits. Similarly, BTEX in borehole water displayed significant differences (p < 0.05) when compared to World Health Organization (WHO) standards, raising alarming concerns about the safety and portability of groundwater in the area. The examination of dumpsite leachate penetration revealed a resistivity anomaly of 8.01 Ωm and an inverse depth of 12.4 m, underscoring profound environmental implications and necessitating immediate remediation efforts. Additionally, Vulnerability and Aquifer Protective Capacity Index (VES) results, with a rating of <0.1, indicated severely compromised aquifer protective capacity, emphasizing the vulnerability of groundwater resources to further contamination. Our study advocates for strategic management, remediation, and monitoring measures to prevent contamination and safeguard water quality in the region.
  • Obrázok miniatúry
    Položka
    Synergizing remote sensing, support vector machine, and aeromagnetic data for precise lithological and mineral potential mapping: a case study from Egypt
    (Taylor & Francis Group : Abingdon, 2026) El-Desoky, Hatem M.; Abdel-Rahman, Ahmed M.; El-Awny, Hamada; Fahmy, Wael; El-Qassas, Reda Abdu Yousef; Abdelrahman, Kamal; Alzahrani, Hassan; Andráš, Peter; Amer, Yahia Z.; Eldosouky, Ahmed Mohammed
    Precise lithological mapping is not only a strong key for exploring new mineralized areas but also could help in achieving the optimal exploitation of mineralized regions. In the present case, cause lithological mapping may provide advice not only to the distribution of possible placer deposit occurrences within the study region but also to small-scale blocks of gold-bearing rocks that are not specifically described in prior geological maps. Therefore, we effectively mapped the exposed rock units in the Hamash region of the Eastern Desert of Egypt by using Support Vector Machine (SVM) to Sentinel 2 data through executing machine learning algorithms (MLAs). This goal involves extensive fieldwork, petrographical examinations, and image processing remote sensing techniques to accurately reveal the exposed lithologies distribution besides the potential relic areas. Moreover, the results disclosed several occurrences of the gold-bearing rocks (e.g. alkali feldspar granites) within the study area besides highlighting the distribution of placer deposits that are mainly concentrated around the old mining workings. The lithological overall allocation accuracy (93.8%) was assessed through a confusion matrix, ground truth rock samples, and previous geological maps. Additionally, the airborne magnetic data were processed and interpreted to detect the main lineament structures controlling the favorable locations with high potential for gold mineralization and associated minerals. Also, the Center for Exploration Targeting (CET) porphyry map depicts the significant gold mineralization zones, which are regarded as targets for follow-up and ground studies. The current contribution greatly encourages further investigations for brownfields as their results could at least enhance a considered area of economic placer deposits, if not highlighting non-exploited lithological blocks.
  • Obrázok miniatúry
    Položka
    Unveiling the mineral resources and structural patterns in the Middle Benue Trough: a comprehensive exploration using airborne magnetic and radiometric data
    (Taylor & Francis Group : Abingdon, 2024) Ekwok, Stephen Eguba; George, Anthony M.; Omori, Asuquo A.; Abdelrahman, Kamal; Ugar, Samuel Izama; Andráš, Peter; Morphy, Morod Iwong; Akpan, Anthony E.; Eldosouky, Ahmed Mohammed
    The Middle Benue Trough (MBT) in Northcentral Nigeria is a geologically significant area with vast mineral resource potential. Employing airborne magnetic and radiometric data, this study utilized the Centre for Exploration Targeting on enhanced total magnetic intensity data to reveal geologic structures, lithological units and mineralization zones. Lineaments predominantly trended in NE-SW direction, with noteworthy orientations in NNE-SSW and E-W. Radiometric anomalies correlated with distinct lithological units, pinpointing granitic gneiss, alluvium, shale, siltstone and sandstone. A magnetically concentrated and potassium-rich area indicated potential polymetallic-magnetic mineralization. The 2D model illustrated igneous intrusions influencing prevalent geologic structures, such as sediment baking and doming. Thorough analysis, including source parameter imaging, standard Euler deconvolution and 2D forward modelling, revealed sediment thicknesses below 1500 m. This research enhances understanding of the MBT’s geological features, offering valuable insights for mineral exploration and resource assessment in the region.