Arabian Journal of Geosciences最新文献

Climate change remains a world tragedy affecting stream flows in catchment areas. This study assessed the impacts of climate change on streamflow along the Kiwira Catchment in the Lake Nyasa Basin, Tanzania, which is important for natural and human ecosystems. The study used climate projections generated from two General Circulation Models (GCMs), downloaded using the LARS-WG statistical methods under the SSP2-4.5 and SSP5-8.5 scenarios. A calibrated HBV hydrological model was used to analyse the future climate scenarios, focusing on mid-century (2025–2060) and end-century (2061–2100) projections. The results indicated alteration in precipitation patterns, including higher rainfall during wet months and lower rainfall in dry months. Temperature projections indicate a steady rise, with maximum temperatures increasing by 0.83 °C mid-century and 1.07 °C by century’s end, while minimum temperatures may rise by 2.61 °C to 3.75 °C under SSP2-4.5 and SSP5-8.5. The HBV model has demonstrated strong performance in simulating streamflow. The model achieved a coefficient of determination(R2) of 0.7 during calibration. Also, the NSE0.68 confirmed model reliability to stimulate streamflow patterns. The streamflow analysis showed variability through increasing peak flows during the wet season and a decline in the dry season, which shows stronger dry seasons and a drop of almost 18m3/s under future projections. Flood Frequency Analysis demonstrated medium floods increasing frequently, and an increase also in extreme events, such as 100-year floods, can be reduced by 30%. Hence, with these results Kiwira Catchment is vulnerable to the impact of climate change and needs adaptive water resources management strategies.

This study assesses the bauxite potential of Nyambaka, located near the Minim-Martap on the Adamawa plateau, one of the bauxite deposits of the Cameroon volcanic line. Twenty-one samples of rock and its weathering cover were collected along a 22-metre-deep pit and submitted to petrography, XRD diffraction, and chemical analyses by ICP-AES and ICP-MS. Upwards, the profile varies from basanite to saprolite, mottled clay, carapace, and duricrust. Porphyritic basanite displays olivine phenocrysts embedded in a matrix of pyroxene, plagioclase, opaque crystals and glass. The lateritic mantle is made up of various amounts of kaolinite, gibbsite, magnetite, goethite, hematite, and anatase. Chemically, basanite displays high concentrations of SiO₂, Fe₂O₃, Al₂O₃, CaO, and MgO, whereas other oxide contents are < 3 wt%. Along the profile, Al₂O₃, Fe₂O₃, MnO, and TiO₂ contents increase while other oxides are leached. Trace element concentrations increase except leached Rb and Sr. REE spectra show no Ce or Eu anomalies except those of the duricrust that display a strong positive Ce anomaly and plot below the basanite. This evidences a change from reducing to oxidizing conditions where CeO₂ precipitates while other REEs are leached. Weathering through monosiallitisation, allitisation and complex migration-accumulation yielded iron-rich bauxites, clayey bauxites, and bauxite iron ores. Bauxitization process was coupled with ferruginisation. Al₂O₃ and Fe₂O₃ concentrations throughout this Nyambaka profile are in the interval of economic thresholds. Thus, it can be considered as a polymetallic indice.

This research aims to investigate the impacts of waste crushed glass powder (GP) as an additive, combined with Lime, on the physical and mechanical properties of clayey soil. It builds on previous knowledge that establishes positive results with waste GP% up to 10%, by extending mix percentages of waste GP to 15%, with 5% fixed Lime content. The mix design samples are tested in laboratories using relevant ASTM standards after curing for 7 days and the results were analyzed using descriptive, graphical and statistical methods. It was found through analysis, mixing 10% of waste GP with 5% of Lime with clayey soil yielded the optimum results in terms of critical mechanical properties. With this combination, the unconfined compressive strength of the clayey soil increased considerably with a slight increase in the coefficient of permeability (k) and shear strength. On the other hand, no substantial change in physical properties was observed due to the addition of GP in combination with lime. This research improves the understanding of clayey soil behavior reinforced with crushed GP. Consequently, this study is among the first to investigate GP–Lime combinations in clayey soils beyond 10% GP content using a full suite of ASTM-standard tests. The findings highlight both improvements (UCS, permeability) and limitations (CBR), offering practical guidance for engineers while reinforcing the environmental benefits of reusing waste glass.

The western continental margin of India is a geologically complex region shaped by hotspot activity, rifting, and volcanic events. Around 65–70 million years ago, the Reunion hotspot interacted with the Indian lithosphere, triggering extensive Deccan volcanic activity. The Saurashtra region in the northwestern Deccan Volcanic Province has undergone substantial tectonic-thermal evolution since the Mesozoic era. To investigate this evolution, a Magnetotelluric (MT) survey was conducted along the Amerili–Porbandar profile in southern Saurashtra, an area marked by volcanic plugs, dyke swarms, and fault systems. 2D modelling of MT data revealed sub-basaltic Mesozoic sediments in the central to western parts of the profile. The data indicate crustal heterogeneities, high-resistivity zones corresponding to volcanic plugs or altered Precambrian crust, and conductive anomalies found between them. Notably, two deep conductivity anomalies were identified at the base of the lower crust in the west, while moderate conductivity features in the central and eastern parts correlate with faults or fractures. Sensitivity analysis confirmed the reliability of these anomalies. The western anomalies likely reflect earlier phases of extension and rifting, later influenced by Deccan volcanism. Mid-crustal anomalies suggest pathways for magmatic intrusion through deep fractures. The interaction of the mantle plume with the crust, along with underplating and fractional crystallization, significantly altered the ancient Precambrian crust.

The mining sector has become a major economic activity worldwide, and one that is well established in Cameroon (Central Africa). The various stages of this exploitation cause considerable damage to the environment and to human health. Soil contamination and mining discharges at the Ngoura locality gold panning sites were assessed by ICP-MS (Inductively Coupled Plasma Mass Spectrometer) measurements of metallic and radioactive trace elements. This study showed a disturbed environment without any restoration, with trace metal elements (TMEs) concentrations mg/kg ranging from 5000 to 100,500 for Fe; 6 to 115 for V; 8.5 to 288.9 for Cr; 37 to 1283 for Mn; 0.7 to 53.5 for Co ; 2.19 to 57.69 for Cu ; 0. 00001 to 85.267 for Ag; 0.01 to 50 Hg; 3.11 to 65.49 for Pb; 0.1 to 1445.7 for As; 1.1 to 476.3 for Th and 0.2 to 29.9 mg/kg for U. These high TME concentrations at Ngoura sites highlight the wide variability of pollution indices. The enrichment factor (EF) displays extreme enrichment for Hg and Ag in some samples, and average for Cr, Mn, Th and U. Geo-accumulation index (Igeo) and contamination factor (CF) values indicate extreme Hg contamination. The pollution index values (PLI) of the studied samples are greater than one, indicating a progressive deterioration in soil quality. In addition, the studied materials at the Ngoura locality are contaminated with heavy metals and radioactive elements (Th and U). These mining wastes are exposed to air, rain, erosion and leaching, and could therefore contaminate ecosystems.

Geotourism plays an increasingly important role in diversifying the Sultanate of Oman’s economy while promoting regional development and cultural heritage preservation. The Saiq Plateau, situated at ~ 2,000 m elevation in the Jabal Akhdar region of the Oman Mountains, represents a prominent geotourism destination accessible via a single road. Visitor records show a steady rise from approximately 100,000 in 2009 to more than 200,000 in 2024, underscoring its growing significance. This study examines the geotourism potential and associated challenges of the Saiq Plateau, with a focus on the remote mountain village of Al-Suwgra. Abandoned in 2009, Al-Suwgra was sustainably redeveloped into an eco-friendly heritage lodge in 2016 through initiatives led by local villagers. This transformation highlights a successful model of community-driven geotourism development in the Sultanate. Preliminary geological and geomorphological assessments indicate that large-scale slope failures are unlikely, as bedding planes dip away from the settlement, and the village is largely protected from rockfalls by encasing carbonate cliffs. A small hanging valley bisecting the site channels seasonal runoff, mitigating debris-flow hazards. The findings highlight that Al-Suwgra integrates sustainable geotourism development with effective geohazard mitigation, offering a replicable framework for mountain communities across the Sultanate.

Soils classified as expansive experience an increase in volume upon contact with water. There have been increased searches for materials to improve and strengthen expansive soils and soils with multiple problems, provided that materials are available and without harm. Attention has turned to the use of polymeric materials, as they are available and environmentally friendly materials that are not harmful (such as cement, which leads to the emission of carbon dioxide). The major purpose of this research is to investigate the effectiveness of various percentages of swelling soil stabilized with Poly Acrylamide Geopolymer. This effectiveness by reducing the free swell and swelling potential for expansive soil. The percentages of Poly Acrylamide Geopolymer are 0, 0.1, 0.3, 0.5, 1, 1.5 and, 3% by weight. The results showed that the optimum percent of Poly Acrylamide Geopolymer is 0.3%. The free swell and swelling pressure decreased by about 75% and 95%, respectively, when 0.3% of geopolymer is added to the expansive soil.

The Agbeju Field, located within the Niger Delta Basin, is an important hydrocarbon-bearing region requiring a detailed petrophysical evaluation to optimize reservoir characterization and hydrocarbon recovery. This study integrates well log data from five wells to identify hydrocarbon-bearing reservoirs and determine their petrophysical properties, including porosity, permeability, net-to-gross ratio, and fluid saturation. The methodology involved the use of Schlumberger Petrel software for data processing, well log correlation, and reservoir ranking based on key petrophysical parameters. Three major reservoirs, designated as Sand A, Sand B, and Sand C, were identified. Among these, Sand C was ranked as the most promising reservoir due to its highest hydrocarbon saturation (41%), moderate porosity, and favorable net-to-gross ratio. Sand A followed closely with similar porosity values but slightly lower hydrocarbon saturation. Sand B, despite exhibiting the highest permeability and net-to-gross ratio, had the highest water saturation, making it less viable for immediate production. The well log correlation confirmed lateral continuity of the reservoirs, indicating an extensive hydrocarbon-bearing system across Agbeju Field. The results underscore the importance of integrating petrophysical analysis with well log interpretation to improve reservoir evaluation accuracy and hydrocarbon recovery efficiency. This study provides critical insights for field development planning, reservoir management, and hydrocarbon extraction strategies in Agbeju Field. Future studies should incorporate seismic data and core sample analysis to enhance reservoir characterization further. The findings contribute to optimizing hydrocarbon recovery and minimizing exploration risks in the Niger Delta and similar petroleum systems.

Estimating total runoff discharge in arid and semi-arid regions poses a significant challenge, particularly in data-scarce environments where real-time hydrological measurements are unavailable. Using a significant rainfall event in November 2018, this paper assesses the SCS-CN approach and its revised models, such as the Mishra-Singh, Woodward, and Huang models, for estimating wadi runoff in Kuwait’s ephemeral (arid) catchments. It was believed to be the heaviest rainfall event Kuwait had seen in a century. The GIS’s HEC-GeoHMS hydrological modeling tools were utilized to determine Curve Number (CN) values based on watershed attributes such as soil type, land use, and digital elevation model (DEM). The uniqueness of this work lies in the integration of HEC-GeoHMS hydrological modeling within GIS to precisely determine CN values in a high-resolution gridded raster map, along with the application of four SCS-CN methods that are well-suited to Kuwait’s catchments and do not require extensive datasets. The performance of the original SCS-CN model and its modified versions is rigorously assessed using multiple statistical metrics to determine the most reliable approach for runoff estimation. In November 2018, runoff volumes were estimated at 95.04 MCM (SCS-CN), 85.94 MCM (Huang), and 158.26 MCM (Mishra-Singh).The Mishra-Singh model achieved the highest coefficient of determination (R² = 0.8374) and the lowest error values, including a Mean Absolute Deviation (MAD) of 1.852, Mean Squared Error (MSE) of 5.079, Root Mean Squared Error (RMSE) of 2.254, Mean Absolute Percentage Error (MAPE) of 63.029, normalized Root Mean Squared Error (nRMSE) of 1.747, Percent Bias (PBIAS) of 0.373, and Nash-Sutcliffe Efficiency (NSE) of 0.991. The Mishra-Singh technique yielded a runoff-rainfall ratio of 21.4% in November 2018 compared to 13.4% using the original SCS-CN method; the observed ratio of 20.8% closely matched the Mishra-Singh model. The findings provide a valuable framework for selecting optimal runoff estimation techniques in wadi systems with limited hydrological data, contributing to improved water resource management and flood mitigation strategies in arid regions.