Results in Earth Sciences最新文献_第2页

Climatic, tectonic, and fluvial controls on the origin and retreat of the Aharbal Waterfall, Himalaya 气候、构造和河流对喜马拉雅阿哈尔巴尔瀑布起源和消退的控制

Results in Earth Sciences

Pub Date : 2025-12-01 DOI: 10.1016/j.rines.2025.100143

Omar Jaan Paul , Reyaz Ahmad Dar , Shakil Ahmad Romshoo

River incision is a fundamental geomorphic process in tectonically active mountain regions, influenced by structural, hydrological, lithological, and morphological factors. This process often results in formation of knickpoints along river courses. The Aharbal Waterfall (AWF) is a structural knickpoint, formed along the Vishav River in Pir Panjal Range of northwestern Himalaya. It originated through continuous erosion of glacial till down to underlying basement rocks, composed of highly jointed basalts and agglomerates. Field investigations supplemented by high-resolution drone surveys indicate that AWF has retreated by approximately 538 m upstream from its original location subsequent to the exposure of basement rocks triggered by intensified fluvial activity in the region. The continued retreat is driven by active tectonics, river incision, and lithological controls. High SL and Ksn values concentrated along the Aharbal reach further support enhanced channel incision and indicate active tectonic forcing associated with the AWF. Numerous step-falls downstream likely mark former positions of the retreating AWF. To quantify retreat rate, we utilized Schmidt hammer (N-type) repeated impact tests and an empirical model evaluating the balance between erosive and resistant forces. Our analysis estimates retreat rate of 0.94 cm/year, which is relatively high given basaltic lithology of the site. The persistent upstream migration is primarily controlled by toppling failure of well-jointed basalts, allowing waterfall to maintain its steep gradient. However, the presence of active faults in the reach especially in vicinity and the potential for landslides in the immediate proximity pose significant geohazards, threatening both the stability of waterfall and surrounding landscape. Understanding these retreat dynamics is critical for assessing long-term landscape evolution and mitigating potential hazards in this tectonically active region.

河流切割是构造活动山区的一个基本地貌过程，受构造、水文、岩性和形态等因素的影响。这一过程往往导致沿河道形成裂缝。阿哈尔巴尔瀑布（AWF）是一个结构上的裂口，形成于喜马拉雅西北部皮尔潘加尔山脉的维沙夫河沿岸。它起源于冰碛物对下伏基底岩的持续侵蚀，基底岩由高度节理的玄武岩和砾岩组成。实地调查和高分辨率无人机调查表明，由于该地区河流活动加剧，基底岩石暴露，AWF从原始位置向上游后退了约538 m。活动构造、河流切割和岩性控制推动了持续的退缩。沿阿哈尔巴尔河段集中的高SL和Ksn值进一步支持河道切口增强，表明与AWF相关的构造作用活跃。下游的许多台阶可能标志着撤退的AWF以前的位置。为了量化后退率，我们使用了施密特锤（n型）重复冲击试验和一个评估侵蚀力和阻力平衡的经验模型。我们的分析估计退缩率为0.94 cm/年，考虑到该地点的玄武岩岩性，这是相对较高的。持续的上游运移主要由节理良好的玄武岩的倾倒破坏控制，使瀑布保持其陡峭的坡度。然而，河段内活动断层的存在，特别是在附近，以及附近潜在的山体滑坡构成了重大的地质灾害，威胁着瀑布和周围景观的稳定性。了解这些后退动力学对于评估这一构造活跃地区的长期景观演变和减轻潜在危害至关重要。

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引用次数: 0

Earthquake Magnitude Detection: Leveraging Machine Learning with Metaheuristics for Feature Selection and Dimensionality Reduction 地震震级检测：利用机器学习与元启发式特征选择和降维

Results in Earth Sciences

Pub Date : 2025-12-01 DOI: 10.1016/j.rines.2025.100145

Rishita Dhulipalla, Shweta Vincent

The rapid and accurate estimation of earthquake magnitude is a cornerstone of effective early warning and hazard mitigation strategies. This study systematically evaluates the efficacy—Particle Swarm Optimization (PSO), Grey Wolf Optimizer (GWO), and Whale Optimization Algorithm (WOA)—as feature selection wrappers for improving earthquake magnitude prediction. Four distinct ML models were benchmarked: Random Forest (RF), Light Gradient Boosting Machine (LightGBM), Support Vector Machine (SVM), and Decision Tree (DT). These models were trained and evaluated on a seismic dataset comprising 1000 events characterized by 598 features. Model performance was rigorously assessed using Mean Squared Error (MSE), Mean Absolute Error (MAE), the Coefficient of Determination (

R^{2}

), feature reduction rates, and total execution time. The results demonstrate that integrating a metaheuristic feature selection approach can yield substantial performance gains. The PSO-optimized Random Forest model achieved the best overall performance, with an MSE of 0.0284 and an

R^{2}

of 0.8547, representing a 23.8 % improvement in MSE over its baseline. Feature selection proved to be a critical enabler for the SVM, transforming it from a non-performing model (

R^{2}

= −0.1716) into a viable predictor, with the PSO-optimized variant achieving an

R^{2}

of 0.6517. The findings conclude that a PSO-based feature selection wrapper offers a robust and highly effective method for enhancing the accuracy and computational efficiency of advanced ML models for seismic analysis.

快速准确地估计地震震级是有效预警和减灾战略的基石。本研究系统地评估了粒子群优化算法（PSO）、灰狼优化算法（GWO）和鲸鱼优化算法（WOA）作为特征选择包装器提高地震震级预测的有效性。对四种不同的ML模型进行基准测试：随机森林（RF），光梯度增强机（LightGBM），支持向量机（SVM）和决策树（DT）。这些模型在包含1000个事件的地震数据集上进行了训练和评估，这些事件具有598个特征。使用均方误差（MSE）、平均绝对误差（MAE）、决定系数（R2）、特征减少率和总执行时间严格评估模型性能。结果表明，集成元启发式特征选择方法可以产生实质性的性能提升。pso优化后的随机森林模型获得了最佳的整体性能，MSE为0.0284，R2为0.8547，MSE比基线提高了23.8%。事实证明，特征选择是支持向量机的关键推动因素，它将支持向量机从一个不良模型（R2= - 0.1716）转变为一个可行的预测器，pso优化的变体实现了R2为0.6517。研究结果表明，基于pso的特征选择包装器为提高地震分析高级ML模型的准确性和计算效率提供了一种鲁棒且高效的方法。

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引用次数: 0

Structural evaluation and hydrocarbon potentials of Emil Field, offshore Niger Delta Basin 尼日尔三角洲近海Emil油田构造评价与油气潜力

Results in Earth Sciences

Pub Date : 2025-11-16 DOI: 10.1016/j.rines.2025.100142

Ekwu Victor Chukwuemeka , Alexander Ogbamikhumi , Sikiru Adeoye Salami , Chekwube Nnamdi Didi

The Emil Field, located in the deep offshore Niger Delta Basin, represents a structurally complex petroleum system shaped by sediment loading, growth faulting, and shale diapirism. This study applies an integrated workflow of seismic interpretation, well log analysis, basin modeling, gross depositional environment (GDE) mapping, and structural evolution to evaluate its structural evolution and hydrocarbon potential. Biostratigraphic and sequence stratigraphic analysis established chronostratigraphic markers, supporting the correlation of six prospective reservoirs (Sands B, D, F, G, M, and R). Burial history and thermal maturity modeling confirm the Akata Formation as the main source rock, with transformation ratios above 90 %, indicating significant hydrocarbon generation since ∼50 Ma. While biodegradation risks occur in shallow intervals, deeper reservoirs preserve better quality. Ten prospects (A–J) were mapped, showing diverse structural styles, including fault-assisted anticlines, domal highs, and rollover closures, reflecting the tectono-stratigraphic evolution of the basin. Structural evolution defined four deformation stages: (1) pre-deformation with continuous strata, (2) early deformation with syn-sedimentary faulting and shale mobilization, (3) late deformation marked by diapiric piercement, truncation, and compartmentalization, and (4) present-day structure with canyons, rollover anticlines, listric faults, and diapiric traps. Isopach and isochores revealed thickness anomalies and truncations around diapirs, confirming their role in sediment distribution and trap geometry. Emil Field’s prospectivity is governed by structural deformation and shale diapirism, which created opportunities in structural and stratigraphic traps but also challenges from reservoir truncation and seal integrity. This integrated approach enhances exploration success in frontier deepwater Niger Delta settings.

Emil油田位于尼日尔三角洲盆地近海深处，是一个由沉积负荷、生长断裂和页岩底辟作用形成的结构复杂的油气系统。本研究采用地震解释、测井分析、盆地建模、总沉积环境（GDE）填图、构造演化等综合工作流程，对该区的构造演化和油气潜力进行了评价。生物地层学和层序地层学分析建立了年代地层标志，支持6个远景储层（砂B、D、F、G、M和R）的对比。埋藏史和热成熟度模拟证实Akata组为主要烃源岩，转化率在90 %以上，表明在~ 50 Ma以来有明显的生烃作用。虽然浅层段存在生物降解风险，但较深的储层保持了较好的质量。10个远景区（A-J）显示出不同的构造样式，包括断层辅助背斜、丘顶隆起和翻滚闭包，反映了盆地的构造-地层演化。构造演化定义了四个变形阶段：(1)以连续地层为特征的预变形阶段；(2)以同沉积断裂和页岩运动为特征的早期变形阶段；(3)以底辟贯通、截断和分区为特征的晚期变形阶段；(4)以峡谷、翻转背斜、盘状断裂和底辟圈闭为特征的现代构造阶段。等厚线和等差线揭示了底辟周围的厚度异常和截断，证实了它们在沉积物分布和圈闭几何中的作用。Emil油田的勘探前景受构造变形和页岩底辟作用的影响，这为构造和地层圈闭创造了机会，但也给储层截断和密封完整性带来了挑战。这种综合方法提高了前沿深水尼日尔三角洲地区的勘探成功率。

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引用次数: 0

Landslide susceptibility mapping along the Udhampur-Ramban section of National Highway-44, Jammu and Kashmir: A case study based on the frequency ratio method 查谟和克什米尔44号国道Udhampur-Ramban路段滑坡易感性制图：基于频率比法的案例研究

Results in Earth Sciences

Pub Date : 2025-11-14 DOI: 10.1016/j.rines.2025.100141

Yudhbir Singh , Shifali Chib , Insha Hamdani , Gaurav Singh Parihar , Sumit Johar , S.K. Pandita

Many chronic landslides occurred in the Himalayas as a result of the ever-increasing amplification of road networks and the tampering of hill slopes for urban development. The purpose of this study is to create a landslide susceptibility map (LSM) using the Frequency Ratio (FR) method for the section of National Highway-44 (NH-44) between Udhampur and Ramban, Jammu and Kashmir. The current study also examines the relationship between the various triggering factors and the landslides along this section of highway. A total of eighty-four landsliding sites were identified and mapped through field visits and satellite imageries to create a landslide inventory. The study showed that the dominant factors influencing the slope’s stability in the study area are elevation and terrain ruggedness index which are followed by the study area's slope aspect and land use land cover. The prepared LSM was divided into very low, low, moderate, high, and very high landslide susceptibility zones, respectively. The current study revealed that 54 % of the study area falls into the very low susceptibility class, 17 % each in the low and moderate susceptibility class, 12 % in the high susceptibility class, and 0 % under very high landslide susceptibility class. The resulting susceptibility map for various zones was evaluated using the receiver operative characteristic (ROC) curve, which yielded comparatively good prediction and success rates of 90.2 % and 84.9 %, respectively. The study offers analytical frameworks and mitigation strategies for successfully minimising the main risks associated with landslide occurrences, shedding light on important information for decision-makers, stakeholders, and planners.

由于道路网络的不断扩大和城市发展对山坡的破坏，在喜马拉雅地区发生了许多慢性滑坡。本研究的目的是使用频率比（FR）方法为查谟和克什米尔之间的Udhampur和Ramban之间的44号国道（NH-44）路段创建滑坡易感性图（LSM）。本研究还探讨了各种诱发因素与该路段滑坡的关系。通过实地考察和卫星图像，共确定和绘制了84个滑坡地点，以编制滑坡清单。研究表明，影响研究区边坡稳定性的主要因素是高程和地形崎岖度指数，其次是坡向和土地利用土地覆被。将制备的LSM分别划分为极低、低、中、高和极高滑坡易感性带。研究表明，研究区极低易感性占54 %，低易感性和中易感性各占17 %，高易感性占12 %，高易感性占0 %，极高易感性占0 %。采用受试者工作特征（ROC）曲线对各区域的敏感性图进行评价，预测成功率分别为90.2 %和84.9 %。该研究为成功地最大限度地减少与滑坡发生有关的主要风险提供了分析框架和缓解战略，为决策者、利益相关者和规划者提供了重要信息。

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引用次数: 0

Integrated structural characterization from airborne geophysical data and field observations: A case study from the left bank of the Sankarani River (Southern Mali) 基于航空地球物理数据和野外观测的综合结构表征：以马里南部桑卡拉尼河左岸为例

Results in Earth Sciences

Pub Date : 2025-11-05 DOI: 10.1016/j.rines.2025.100140

Aboubacar Denon , Gbele Ouattara , Ousmane Wane , Baco Traoré , Adama Youssouf Koné , Souleymane Sangaré

Magnetic and electromagnetic surveys carried out over the left bank of the Sankarani River, in southern Mali, outline a structural pattern that matches field observations in key areas. Residual field data with values ranging from −173.94 nT to 286.85 nT were used to produce various maps. These data (magnetic and electromagnetic) show a set of magnetic and conductive lineaments-oriented NW–SE, N–S, NE–SW, and E–W. Several coincide with mapped structures and correspond to major discontinuities, including shear zones that can be followed to depths of several hundred metres. Field-based structural analysis confirms that these lineaments correspond to a complex deformation history involving four successive phases, labelled D1 through D4. D1 reflects a continuum of deformation subdivided into two stages: D1a, associated with WNW–ESE coaxial shortening and responsible for fold stacking and thrusting; and D1b, characterized by NW–SE ductile shearing that generated predominantly sinistral N–S strike-slip faults, dextral NE–SW conjugate faults, and an NNE- to NE-trending foliation. D2 records NE–SW shortening and is associated with disharmonic folds (P2) and a second schistosity (S2). D3 corresponds to brittle deformation of late Eburnean age, while D4 is marked by the intrusion of Mesozoic dolerite dykes reflecting late-stage structural reactivation. The overlay of interpreted lineaments with artisanal gold mining sites reveals a strong spatial correspondence, particularly along shear zones. This association supports a structural control on mineralization and highlights the metallogenic significance of these features for identifying prospective areas.

在马里南部桑卡拉尼河左岸进行的磁场和电磁调查勾勒出了一个与关键地区的实地观测相匹配的结构模式。残差野外数据的取值范围从- 173.94 nT到286.85 nT，用于生成各种地图。这些数据（磁性和电磁）显示了一组面向NW-SE， N-S， NE-SW和E-W的磁性和导电线。其中一些与地图上的构造相吻合，并与主要的不连续面相对应，包括可以追踪到几百米深处的剪切带。基于现场的结构分析证实，这些线条对应于一个复杂的变形历史，包括四个连续的阶段，标记为D1到D4。D1反映了连续的变形，分为两个阶段：D1a与WNW-ESE共轴缩短有关，负责褶皱堆积和逆冲；D1b以NW-SE韧性剪切为特征，主要发育左旋N-S走滑断裂、右旋NE-SW共轭断裂和NNE- ne走向的片理构造。D2记录NE-SW缩短，并与非调和褶皱（P2）和第二片理（S2）有关。D3对应晚eburne时代的脆性变形，而D4代表中生代白云岩岩脉的侵入，反映了晚期的构造活化。解释的轮廓与手工金矿遗址的叠加显示出强烈的空间对应关系，特别是沿着剪切带。这种联系支持了构造对成矿的控制，并突出了这些特征对寻找远景区域的成矿意义。

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引用次数: 0

Validation of dry bulk pile volume estimation algorithm based on angle of repose using experimental images 基于休止角的干散体桩体积估计算法的实验验证

Results in Earth Sciences

Pub Date : 2025-11-04 DOI: 10.1016/j.rines.2025.100137

Madhu Koirala , Pål Gunnar Ellingsen , Ashenafi Zebene Woldaregay

Estimation of volume of piles in shipping ports plays a pivotal role for logistics management, facilitates better ship rescheduling and rerouting for economic benefits and contributes to overall efficient shipping management. This paper presents validation results for a volume estimation algorithm for dry bulk cargo piles stored in open ports. Using remote sensing images obtained in a laboratory setting, the method first detects the contour of the pile and then reconstructs its 3D model based on the material’s angle of repose, and estimates the volume accordingly. We validated the algorithm on full conical piles and single-ridge elongated piles, and further tested it on reclaimed conical and elongated piles. The results demonstrated the algorithm’s strong potential for accurately estimating pile volume from experimental images and a reference satellite image, achieving high accuracy in our validation.

船舶港口桩体积估算对物流管理具有举足轻重的作用，有利于船舶更好地调度和改道，提高经济效益，有利于船舶的整体高效管理。本文给出了一种干散货散货堆垛容积估计算法的验证结果。该方法利用在实验室环境下获得的遥感图像，首先检测桩的轮廓，然后根据材料的休止角重建桩的三维模型，并据此估算体积。在全桩和单桩上验证了该算法，并在再生桩和再生桩上进一步验证了该算法。结果表明，该算法在从实验图像和参考卫星图像中准确估计桩体体积方面具有很强的潜力，在我们的验证中达到了很高的精度。

引用次数: 0

Integrating field data, petrography, and induced polarization geophysical survey for 3D modeling and delineation of gold mineralization targets in Bissiang area, Nyong group, Cameroon 结合野外资料、岩石学和诱导极化物探，对喀麦隆Nyong群Bissiang地区金矿化靶区进行三维建模和圈定

Results in Earth Sciences

Pub Date : 2025-11-02 DOI: 10.1016/j.rines.2025.100139

Kouankap Nono Gus Djibril , Mohamed Moustapha Ndam Njikam , Alessandra Ribodetti , Njikeu Olivier , Ntoogue Paul , Robillard Claude

Stream sediments sampling, lithological observations and induced polarization (IP) survey were carried out in Bissiang area, located at the northwestern border of the Congo Craton in Cameroon. The aim of the study was to delineate potential gold targets through the integration of field, petrographic, and geophysical data. Most stream sediment samples yielded alluvial gold particles, suggesting a mineralized catchment composed of quartzite, schist, and gneiss. Inverted chargeability sections helped identify Very High Chargeability (VHC) and High Chargeability (HC) domains, interpreted as potential primary and secondary gold targets, respectively. Their spatial correlation revealed a N-S-trending anomaly affected by a dextral fault, and a 3D model of the VHC (25–44 mV/V) and HC (15–25 mV/V) domains was developed. The volume of the primary VHC targets was estimated at 340,388,500 m³ and that of the secondary or HC targets at 705,358,000 m³. These results provide a basis for further exploration and drilling campaigns.

在喀麦隆刚果克拉通西北边界的Bissiang地区进行了水系沉积物取样、岩性观测和激电测量。研究的目的是通过整合野外、岩石学和地球物理数据来圈定潜在的金矿目标。大多数水系沉积物样本都产生了冲积金颗粒，表明这是一个由石英岩、片岩和片麻岩组成的矿化集水区。倒置的可充电性剖面有助于确定极高可充电性（VHC）和高可充电性（HC）结构域，分别被解释为潜在的初级和次级黄金目标。空间相关性揭示了受右旋断层影响的n - s向异常，建立了VHC（25-44 mV/V）和HC（15-25 mV/V）域的三维模型。VHC主要目标的体积估计为340,388,500 m3，次要或HC目标的体积估计为705,358,000 m3。这些结果为进一步的勘探和钻井活动提供了基础。

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引用次数: 0

Scaling seismicity with depth: b-value, correlation dimension, and return periods analysis in far Western Nepal 尼泊尔远西部地震活动性的深度标度：b值、相关维数和回归期分析

Results in Earth Sciences

Pub Date : 2025-10-31 DOI: 10.1016/j.rines.2025.100138

Ram Krishna Tiwari, Harihar Paudyal

This study investigates the depth-dependent variations of b-value and fractal dimension using earthquake data from Far Western Nepal, employing three estimation methods: Maximum Likelihood Estimation (ML), Bayesian Method (BM), and Gumbel Method (GM). The results reveal a characteristic fractal scale of ∼7.5–35 km, corresponding to the brittle-ductile transition zone in the crust. The correlation dimension increases from 0.4 (0–10 km depth) to ∼1.2 (12–24 km), indicating a transition from clustered seismicity to more homogeneous stress distribution. The b-values exhibit a decreasing trend with depth, with higher values (0.57–0.74) in shallow crustal layers (0–10 km) and lower values (0.23–0.34) at greater depths (>20 km), suggesting a shift from heterogeneous fracture-dominated deformation to more uniform stress release in ductile regimes. A strong negative correlation (R² > 0.7) between b-value and correlation dimension is observed for ML and BM, while the GM shows weaker dependence (R² = 0.17). Return period analysis indicates frequent small-magnitude earthquakes (M ∼5–5.5) with decadal recurrence, whereas larger events (M ≥5) have centennial return periods. The probability of exceedance analysis further confirms that minor earthquakes (M = 4–5) are likely within short timeframes, while larger events (M ≥ 5.5) become increasingly probable over longer periods. The notable difference in the seismic indicators with depth suggest future major earthquakes in Far Western Nepal will likely occur below 20 km depth. We recommend integrating these depth-varying seismic indicators into hazard models to enhance earthquake preparedness and risk reduction strategies.

本文利用尼泊尔远西部地震资料，采用极大似然估计（ML）、贝叶斯方法（BM）和甘贝尔方法（GM）三种估计方法，研究了b值和分形维数的深度相关变化。结果表明，分形尺度为~ 7.5 ~ 35 km，对应于地壳的脆性-韧性过渡带。相关维数从0.4（0-10 km深度）增加到~ 1.2（12-24 km深度），表明从聚集性地震活动向更均匀的应力分布转变。b值随深度减小，浅层（0-10 km）值较高（0.57-0.74），深层（20 km）值较低（0.23-0.34），表明韧性区应力释放由非均质断裂为主向均匀变形转变。ML和BM的b值与相关维数呈较强的负相关（R²> 0.7）， GM的相关性较弱（R²= 0.17）。回归周期分析表明，频繁的小震级地震（M ~ 5 - 5.5）具有十年重现性，而较大的地震（M≥5）具有百年重现性。超出概率分析进一步证实，小地震（M = 4-5）可能在短时间内发生，而大地震（M≥5.5）在较长时间内发生的可能性越来越大。地震指标与深度的显著差异表明，尼泊尔远西部未来的大地震可能发生在20 公里深度以下。我们建议将这些深度变化的地震指标纳入灾害模型，以加强地震防备和减少风险战略。

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引用次数: 0

Prioritizing groundwater recharge zones through morphometric and geospatial analysis: A case study of the Musi River basin,Telangana, India 通过形态计量学和地理空间分析确定地下水补给区的优先顺序：以印度特伦加纳邦Musi河流域为例

Results in Earth Sciences

Pub Date : 2025-10-13 DOI: 10.1016/j.rines.2025.100136

Linga Swamy Jogu , Naveen Kumar Gardas

Groundwater availability in the Archaean granitic basement, Proterozoic sedimentary rocks, and Deccan Traps of Telangana is strongly influenced by lithology, weathered-zone thickness, flow morphology, and structural features. Rapid population growth and urban expansion have intensified water demand, leading to acute groundwater depletion, particularly in the Musi River basin. The present study aims to delineate potential zones for groundwater recharge by: (i) computing linear, areal, and relief morphometric parameters for eight sub-basins; (ii) prioritizing sub-basins using Weighted Sum Analysis (WSA) informed by statistical correlations and validated against Analytical Hierarchical Process (AHP) results; and (iii) identifying dominant morphometric parameters using Principal Component Analysis (PCA). Eleven key morphometric parameters were considered and weighted according to hydrological significance. One-way ANOVA confirmed significant differences in groundwater recharge potential across priority classes (F = 12.36, p = 0.015). Results indicate that MSB-7 exhibits the highest recharge potential (suitability index = 2.79), while MSB-1 is the least suitable (index = 6.45). Based on index values, sub-basins were classified into four priority categories, with approximately 47 % of the basin falling under ‘very good’–‘good’ zones. PCA revealed that drainage density, drainage texture, and stream frequency (PC1; 33.29 % variance) and relief-related parameters (PC2; 32.69 % variance) are the most influential controls on recharge. These findings provide actionable guidance for targeted watershed interventions including check dams, percolation tanks, and rainwater harvesting to enhance groundwater sustainability in the Musi River basin.

泰伦加纳地区太古宙花岗岩基底、元古代沉积岩和德干圈闭的地下水有效性受岩性、风化带厚度、水流形态和构造特征的强烈影响。人口的快速增长和城市扩张加剧了对水的需求，导致地下水严重枯竭，特别是在木斯河流域。本研究旨在通过以下方法来划定地下水补给的潜在区域：(i)计算8个子盆地的线性、面积和地形形态参数；（ii）利用加权和分析（WSA）对子流域进行优先排序，该分析基于统计相关性，并根据层次分析法（AHP）结果进行验证；（iii）使用主成分分析（PCA）确定主要形态计量参数。根据水文意义对11个关键形态参数进行了考虑和加权。单因素方差分析证实了不同优先级地下水补给潜力的显著差异（F = 12.36, p = 0.015）。结果表明：MSB-7的充电电位最高（适宜指数为2.79），MSB-1的充电电位最低（适宜指数为6.45）；根据指数值，将子盆地划分为4个优先级，约47% %的盆地属于“非常好”-“好”带。主成分分析表明，排水密度、排水质地、水流频率（PC1； 33.29 %方差）和地形相关参数（PC2； 32.69 %方差）是影响补给的主要因素。这些发现为有针对性的流域干预措施提供了可操作的指导，包括拦河坝、渗水池和雨水收集，以增强木斯河流域地下水的可持续性。

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引用次数: 0

Geometric structure and hydrodynamic assessment of mio-pliocene aquifers in the Douala sedimentary sub-basin, Cameroon: First appraisal 喀麦隆Douala沉积次盆地中新世-上新世含水层几何结构及水动力评价：首次评价

Results in Earth Sciences

Pub Date : 2025-10-11 DOI: 10.1016/j.rines.2025.100135

Cyrille Donald Njiteu Tchoukeu , Yvon Bertil Nlend , Boris Djieugoue , Kevin Mickus , Akumbom Vishiti , Jacques Etame , Suzanne Ngo Boum Nkot

Effective groundwater management depends on accurately identifying water access points, quantifying available volumes, and understanding subsurface flow dynamics. This is particularly critical in developing countries where groundwater often represents the primary, and sometimes sole source of safe drinking water - especially in densely populated urban centres. In this study, a combination of geophysical methods, lithostratigraphic data, and hydrodynamic parameters was employed to characterize the geometry and properties of the Mio-Pliocene aquifer system the Douala basin in Cameroon. Using the vertical electrical sounding method and the Schlumberger array along a profile of approximately 166 m, combined with data from 20 boreholes including well-log profiles and hydraulic measurements, the underdeveloped aquifers less than 30 m thick, located around 20 m below the surface. More prominent and hydraulically significant sandy layers were detected at depths of 40–50 m, extending down to about 120 m. Three distinct hydrogeological zones were identified: (a) a shallow layer composed mainly of sandy, clayey, and sandy-clay materials; which outcrops in various areas and is located close to river systems; (b) a thinner intermediate layer characterised by gravelly-sandy and sandy-clay sediments; which constitute an underground extension of the unconfined aquifers. (c) A deep aquifer layer with more consistent lateral facies distribution and greater overall thickness. This deep aquifer system also demonstrated better structural continuity and a confined unit that represents the best underground reservoir for useable water. Piezometric levels across the study area ranged from 12.9 to 36.1 m, with well yields between 8.3 and 33.2 m³ /h and drawdowns from 1.19 to 11.3 m. Transmissivity values varied from 0.003 to 0.087 m²/s, generally increasing towards the coastal zone. These values are a potential indicator of the vulnerability of shallow and semi-shallow aquifers to salt water intrusion, from the surface to roughly 40 m. The geology and topography strongly influence groundwater flow behaviour. These findings provide valuable data that can inform future strategies to improve groundwater accessibility and ensure sustainable water resource management. Due to the fact that the Douala basin is completely connected to the Atlantic Ocean and consists mainly of porous and permeable formations, this study provides opportunities not only for a better understanding of its hydrogeological structure, but also for spatial monitoring of its interaction with seawater and intercontinental stresses.

有效的地下水管理取决于准确地确定取水点，量化可用水量，并了解地下流动动力学。这在发展中国家尤其重要，因为地下水往往是安全饮用水的主要来源，有时甚至是唯一来源，特别是在人口密集的城市中心。本文采用地球物理方法、岩石地层资料和水动力参数相结合的方法，对喀麦隆Douala盆地中新世-上新世含水层系统的几何形态和性质进行了表征。利用垂直电测深方法和斯伦贝谢阵列，沿着约166 m的剖面，结合20个井眼的数据，包括测井剖面和水力测量，发现了厚度小于30 m的欠发达含水层，位于地表以下20 m左右。在40-50 m深度处发现了更突出和具有水力意义的砂质层，一直延伸到120 m左右。确定了3个不同的水文地质带：(a)主要由砂质、粘土和砂-粘土物质组成的浅层；在不同地区露头，靠近河流系统；(b)较薄的中间层，以砾质砂质和砂质粘土沉积物为特征；构成无承压含水层的地下延伸。(c)横向相分布更一致、总厚度更大的深层含水层。该深层含水层系统还显示出更好的结构连续性和一个密闭单元，代表了可用水的最佳地下水库。整个研究区域的压力水平范围为12.9至36.1 m，井产量范围为8.3至33.2 m³ /h，压降范围为1.19至11.3 m。透过率值在0.003 ~ 0.087 m²/s之间变化，向海岸带方向总体增加。这些值是浅层和半浅层含水层对海水入侵的脆弱性的潜在指标，从地表到大约40 m。地质和地形强烈影响地下水的流动行为。这些发现提供了有价值的数据，可以为未来改善地下水可及性和确保可持续水资源管理的战略提供信息。由于Douala盆地与大西洋完全相连，主要由多孔和渗透地层组成，因此本研究不仅为更好地了解其水文地质构造提供了机会，而且为其与海水和洲际应力相互作用的空间监测提供了机会。

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