Search Results (56)

This study applies the Weighted Overlay Analysis (WOA) method integrated with GIS to assess landslide susceptibility along Al Figrah Road in Al-Madinah Al-Munawarah, western Saudi Arabia. Seven key conditioning factors, elevation, slope, aspect, drainage density, lithology, soil type, and precipitation were integrated using high-resolution remote sensing data and expert-assigned weights. The output susceptibility map categorized the region into three zones: low (93.5 million m²), moderate (271.2 million m²), and high risk (33.1 million m²). Approximately 29% of the road corridor lies within the low-risk zone, 48% in the moderate zone, and 23% in the high-risk zone. Ten critical sites with potential landslide activity were detected along the road, correlating well with the high-risk zones on the map. Structural weaknesses in the area, such as faults, joints, foliation planes, and shear zones in both igneous and metamorphic rock units, were key contributors to slope instability. The findings offer practical guidance for infrastructure planning and geohazard mitigation in arid, mountainous environments and demonstrate the applicability of WOA in data-scarce regions. Full article

Land cover, topography, precipitation, and socio-economic factors exert both direct and indirect influences on urban land surface temperatures. Within the broader context of global climate change, these influences are magnified by the escalating intensity of the urban heat island effect. However, the interplay and underlying mechanisms of natural and socio-economic determinants of land surface temperatures remain inadequately explored, particularly in the context of cold-region cities located in the northern temperate zone of China. This study focuses on Changchun City, employing multispectral remote sensing imagery to derive and spatially map the distribution of land surface temperatures and topographic attributes. Through comprehensive analysis, the research identifies the principal drivers of temperature variations and delineates their seasonal dynamics. The findings indicate that population density, night-time light intensity, land use, GDP (Gross Domestic Product), relief, and elevation exhibit positive correlations with land surface temperature, whereas slope demonstrates a negative correlation. Among natural factors, the correlations of slope, relief, and elevation with land surface temperature are comparatively weak, with determination coefficients (R²) consistently below 0.15. In contrast, socio-economic factors exert a more pronounced influence, ranked as follows: population density (R² = 0.4316) > GDP (R² = 0.2493) > night-time light intensity (R² = 0.1626). The overall hierarchy of the impact of individual factors on the temperature model, from strongest to weakest, is as follows: population, night-time light intensity, land use, GDP, slope, relief, and elevation. In examining Changchun and analogous cold-region cities within the northern temperate zone, the research underscores that socio-economic factors substantially outweigh natural determinants in shaping urban land surface temperatures. Notably, human activities catalyzed by population growth emerge as the most influential factor, profoundly reshaping the urban thermal landscape. These activities not only directly escalate anthropogenic heat emissions, but also alter land cover compositions, thereby undermining natural cooling mechanisms and exacerbating the urban heat island phenomenon. Full article

As open-pit mining extends to greater depths, slope stability is becoming a critical factor in ensuring safe production. This issue is particularly pronounced in geological settings with weak interlayers, where sudden slope failures are more likely to occur, demanding precise and reliable stability assessment methods. In this study, a typical open-pit slope with weak interlayers was investigated. Acoustic testing and ground-penetrating radar were employed to identify rock mass structural features and delineate loose zones, enabling detailed rock mass zoning and the development of numerical simulation models for stability analysis. The results indicate that (1) the slope exhibits poor overall integrity, dominated by blocky to fragmented structures with well-developed joints and significant weak interlayers, posing a severe threat to stability; (2) in the absence of support, the slope’s dissipated energy, displacement, and plastic zone volume all exceeded the failure threshold (Δ < 0), and the safety factor was only 0.962, indicating a near-failure state; after implementing support measures, the safety factor increased to 1.31, demonstrating a significant improvement in stability; (3) prior to excavation, the energy damage index (ds) in the 1195–1240 m platform zone reached 0.82, which dropped to 0.48 after reinforcement, confirming the effectiveness of support in reducing energy damage and enhancing slope stability; (4) field monitoring data of displacement and anchor rod forces further validated the stabilizing effect of the support system, providing strong assurance for safe mine operation. By integrating cusp catastrophe theory with energy-based analysis, this study establishes a comprehensive evaluation framework for slope stability under complex geological conditions, offering substantial practical value for deep open-pit mining projects. Full article

Ecological network construction has been widely accepted and applied to guide regional ecological conservation and restoration. For arid regions, ecological networks proposed based on ecological risk assessments are better aligned with the sensitive and fragile characteristics of local ecosystems. This study assesses landscape ecological risk in Wensu County, located on the southern slope of the Tianshan Mountains in the arid region of northwestern China, and it further proposes an optimized ecological network. A multidimensional framework composed of the natural environment, human society, and landscape patterns was employed to construct an ecological risk assessment system. Spatial principal component analysis (SPCA) was applied to identify the spatial pattern of ecological risk. Morphological spatial pattern analysis (MSPA) and a minimum cumulative resistance (MCR) model integrated with circuit theory were used to extract the ecological sources and delineate the ecological corridors. The results reveal significant spatial heterogeneity in terms of ecological risk: Low-risk zones (16.26%) are concentrated in the southwestern forest and water areas. In comparison, high-risk zones (28.27%) are mainly distributed in the northern mountainous mining region. A total of 24 ecological source patches (4105.24 km²), 44 ecological corridors (313.6 km), 39 ecological pinch points, and 38 ecological barriers were identified. Following optimization, the Integral Index of Connectivity (IIC) increased by 89.04%, and the Landscape Coherence Probability (LCP) rose by 105.23%, indicating markedly enhanced ecological connectivity. The current ecological network exhibits weak connectivity in the south and fragmentation in the central region. Targeted restoration of critical nodes, optimization of corridor configurations, and expansion of ecological sources are recommended to improve landscape connectivity and promote biodiversity conservation. Full article

Landslides pose a significant threat to the safety and stability of settlements in karst regions worldwide. The long-standing tight balance state of settlement funding and infrastructure makes it difficult to allocate disaster prevention resources effectively against landslide impacts. There is an urgent need to fully leverage the landscape resources of karst settlements and develop landslide risk prevention strategies that balance economic viability with local landscape adaptability. However, limited research has explored the differential resilience characteristics and patterns of landslide disaster risk and settlement landscapes from a spatial coupling perspective. This study, based on landslide disaster and disaster-adaptive landscape data from a typical karst province in China, employs the frequency ratio-random forest model and weighted variance method to construct landslide disaster risk (LDR) and disaster-adaptive landscape (DAL) base maps. The spatial characteristics of urban, urban–rural transition zones, and rural settlements were analyzed, and the resilience differentiation and driving factors of the LDR–DAL coupling relationship were assessed using bivariate spatial autocorrelation and geographical detector models. The key findings are as follows: (1) Urban and peri-urban settlements exhibit a high degree of spatial congruence in the differentiation of LDR and DAL, whereas rural settlements exhibit distinct divergence; (2) the Moran’s I index for LDR and DAL is 0.0818, indicating that urban and peri-urban settlements predominantly cluster in H-L and L-L types, whereas rural settlements primarily exhibit H-H and L-H patterns; (3) slope, soil organic matter, and profile curvature are key determinants of LDR–DAL coupling, with respective influence strengths of 0.568, 0.555, and 0.384; (4) in karst settlement development, augmenting local vegetation in residual mountain areas and parks can help maintain forest ecosystem stability, effectively mitigating landslide risks and enhancing disaster-adaptive capacity by 6.77%. This study helps alleviate the contradiction between high LDR and weak disaster-adaptive resources in the karst region of Southwest China, providing strategic references for global karst settlements to enhance localized landscape adaptation to landslide disasters. Full article

Deep gravitational slope deformations (DsGSDs) are a geological and engineering challenge with important implications for slope stability, the reliability of existing infrastructures, land use and, above all, the safety of settlements. This paper focuses on the DsGSD phenomenon that affects a large part of the Borrano hamlet, located in the municipality of Civitella del Tronto (Abruzzo Region, Central Italy). This instability is characterized by slow movements of large volumes of material. The main factors initiating deformations are a combination of geological and hydrogeological aspects. These factors include the complex local stratigraphy, composed of pelitic and arenaceous facies at high slope dip angles, and extreme natural events such as heavy rainfall and earthquakes. This study employs a multidisciplinary approach integrating in field activities such as remote-controlled surface monitoring (clinometers and strain gauges), in-depth monitoring (inclinometers and piezometers), aero-photogrammetric analysis and numerical modelling. These techniques permitted us to characterize the evolution of the slope and to identify both the critical sliding surfaces and the mechanisms governing the ground movements. Soil deformations were mainly observed in the central zone of the hamlet. Significant deformations were recorded along planes of weakness at depth between arenaceous and pelitic materials. These planes represent contact zones between the clayey–marly facies, characterized by low strength, and the arenaceous facies, characterized by higher stiffness, creating a mechanical contrast that favours the development of large deformations. The numerical analyses confirmed good correlation with the monitoring data, revealing in detail the instability of both local and territorial processes. The 3D numerical analysis showed how the movements are controlled by planes of weakness, highlighting the key rule of geological discontinuities. Full article

The Niger Basin is a typical marginal basin with complex internal structures and abundant oil and gas resources, exhibiting unique marine geological characteristics and processes. The distribution and deformation characteristics of Akata Formation mudstone in the basin significantly influence hydrocarbon accumulation. In this study, four analogue models were used to analyze the main factors affecting mudstone tectonics and establish an evolution model of mudstone structures. The results show that the tectonic features in the basin reflect the combined influence of gravity sliding and spreading. The main mechanism driving mudstone deformation is gravity spreading caused by differential loading. The basement morphology is the decisive factor in the development of zonation involving extension, translation, and contraction zones. The development of mudstone structures is also affected by the inclination of the basement slope and the thicknesses of both the mudstone layer and overlying layers. A relatively large basement slope inclination is conducive to the rapid flow of mudstone, leading to the rapid development of mudstone formations. A thin mudstone layer with weak plastic mobility is favorable for the full development of mudstone formations. A relatively thick overburden leads to enhanced gravity spreading, which in turn leads to the formation of larger and more numerous mudstone structures. The formation and evolution of mudstone structures in the Niger Basin involved through three stages: (1) during the Paleocene–Middle Oligocene, thick marine mudstone was deposited; (2) in the Middle Oligocene–Late Oligocene, the mudstone and overlying layers were strongly deformed, and numerous mudstone structures developed with tectonic zonation; and (3) since the Pliocene, the tectonic activity in the basin weakened. The simulation of the evolutionary process and evolutionary model established in this study improves the understanding of mudstone tectonics and provides a reference for analyzing the genetic mechanism and hydrocarbon exploration in the basin. Full article

Amid the increasing demands for ecological civilization and food security, addressing conflicts between agricultural and ecological functions has become a critical priority in spatial governance. Focusing on the Chang-Zhu-Tan Urban Cluster, this study establishes a multi-indicator evaluation framework and employs a weighted model to measure agricultural and ecological functions. The ESDA model characterizes the spatial distribution and clustering patterns of conflicts, while the RF model identifies the key drivers and underlying mechanisms. The results indicate the following: (1) Agricultural functions exhibit a “center-weak, periphery-strong” spatial pattern, with high-function zones covering over 60% of the area, whereas ecological functions are primarily concentrated in low-function zones, with high-function areas localized in the northeast. Overall, agro-ecological functionality declined from 2000 to 2020, accompanied by increased gradient differentiation. (2) High-conflict zones decreased by 7.73% during the study period, while medium-conflict and conflict-free zones expanded. Spatially, a trend of “peripheral mitigation of high conflicts and central expansion of low conflicts” emerged. (3) Natural environmental factors were the primary drivers of conflict dynamics, while land use factors gained significance over time. Elevation and slope dominated in 2000 and 2020, whereas land use economic density and crop planting area were more influential in 2010. Synergistic effects were observed, with slope–precipitation interactions providing the strongest explanatory power. This study offers empirical insights into managing agricultural–ecological conflicts, thereby contributing to enhanced spatial governance and sustainable development practices. Full article

Redbed soft rocks, widely distributed in China, are highly susceptible to weathering, disintegration, and strength reduction under environmental and engineering disturbances, posing critical challenges for slope stability. This study investigates the stability and failure mechanisms of high road-cut slopes in redbed regions under excavation, seismic, and rainfall conditions. Numerical simulations were conducted based on actual engineering sites, using the FLAC3D finite difference model to simulate conditions typical of these sites while incorporating realistic geological features such as weak interlayers and fluid–solid coupling effects. Results reveal that under excavation, the slope exhibits displacement discontinuities and stress concentration near weak interlayers. However, the safety factor of the redbed slope remains at 1.58 at this stage, suggesting that large-scale collapses or landslides are unlikely. Seismic loading amplifies displacements and accelerations, with the maximum deformation reaching a shear displacement of 0.81 m, observed in the upper sections of the redbed slope. Under prolonged rainfall, the slope experiences increased saturation and sliding along interlayer surfaces, driven by reduced shear strength. Combined influences of these factors highlight the vulnerability of redbed slopes to localized failure in weakly weathered zones, necessitating targeted reinforcement strategies. These findings provide a deeper understanding of redbed slope behavior under complex conditions, addressing key challenges in geotechnical and transportation infrastructure engineering. Full article

For a binary structure slope with a soil layer on the top and a rock layer on the bottom, during the rainfall process, surface runoff will cause soil and water loss on the slope surface and damage to the slope environment. When rainwater infiltrates into the slope, the pore water pressure in the soil gradually increases, the shear strength of the soil decreases, and a weak zone is formed at the soil–rock interface, which has a significant impact on the stability of the slope. Therefore, to study the soil and water loss on the slope surface and the stability of the slope under rainfall conditions, we used theoretical analysis, indoor model tests, and numerical simulations to conduct a comprehensive exploration of this issue, and the following conclusions were formed: the pore water pressure in the shallow layer is greater than that in the deep layer, and the pore water pressure at the toe of the slope is greater than that at the top of the slope; as the slope gradient increases, the time when the pore water pressure at the toe of the slope begins to respond gradually speeds up; the slope displacement first occurs at the lower part of the slope, then in the middle, and finally at the upper part; the time when the displacement at each point on the slope surface begins to respond gradually speeds up with the increase in the slope; the damage form at a small slope gradient is mainly flow sliding, and the damage process is continuous; the damage form at a large slope gradient is mainly flow sliding and overall sliding, and the damage process is continuous and sudden; when the binary structure slope fails, the sliding surface includes the internal sliding surface of the soil and the sliding surface at the soil–rock interface, but when the slope gradient is small, the relative sliding at the soil–rock interface is small, and a continuous sliding surface cannot be formed; and when the slope gradients are small (30° and 40°), the displacement decreases continuously from top to bottom, and no overall sliding surface is formed. The larger values of plastic strain mainly occur in the upper and middle parts of the slope, there is no formation of a continuous plastic strain zone, and the damage mode is flow sliding; when the slope gradients are large (50° and 60°), the displacement is the largest in the upper part, and a large displacement also occurs in the lower part, forming a sliding surface that penetrates through the soil–soil and rock–soil layers. The larger values of plastic strain occur in the upper, middle, and lower parts of the slope, a continuous plastic strain zone is formed, and the damage modes are flow sliding and overall sliding; numerical simulations were carried out on a typical actual slope, and consistent results were obtained. Full article

The different spatial distribution forms of rock mass structural planes create weak zones in the rock mass, which is also a key factor in controlling rock mass stability. Accurately and efficiently identifying rock mass structural planes and obtaining their dominant orientations is critical for rock mass engineering design and construction. Traditional surveying methods for high and steep rock mass structural planes pose high safety risks, offer limited data, and make comprehensive statistical analysis difficult. This paper utilizes complex rock mass surface 3D point cloud data obtained through 3D laser scanning technology and uses the Hough space transform method to calculate the normal vectors of the 3D point cloud. Based on the difference in normal vectors and surface variation, region growing segmentation is applied to identify and extract rock mass structural planes. Additionally, the fast search and density peak clustering method (CFSFDP) is used for clustering analysis of the rock mass structural planes to obtain dominant orientations. This method was applied to a highway’s high and steep rock slope, successfully identifying 281 structural planes and two sets of dominant structural planes. The orientation of the dominant structural planes identified through RocScience Dips 7.0 analysis showed a deviation of no more than ±3°, complying with engineering standards. The research results offer a feasible solution for the identification of high and steep rock mass structural planes and the extraction of the orientation of dominant structural planes. Full article

The skill, assumptions, and uncertainty of machine learning techniques (MLTs) for downscaling global climate model’s precipitation to the local level in Bolivia were assessed. For that, an ensemble of 20 global climate models (GCMs) from CMIP6, with random forest (RF) and support vector machine (SVM) techniques, was used on four zones (highlands, Andean slopes, Amazon lowlands, and Chaco lowlands). The downscaled series’ skill was evaluated in terms of relative errors. The uncertainty was analyzed through variance decomposition. In most cases, MLTs’ skill was adequate, with relative errors less than 50%. Moreover, RF tended to outperform SVM. Robust (weak) stationary (perfect prognosis) assumptions were found in the highlands and Andean slopes. The weakness was attributed to topographical complexity. The downscaling methods were shown to be the dominant source of uncertainties. This analysis allowed the derivation of robust future projections, showing higher annual rainfall, shorter dry spell duration, and more frequent but less intense high rainfall events in the highlands. Apart from the dry spell’s duration, a similar pattern was found for the Andean slopes. A decrease in annual rainfall was projected in the Amazon lowlands and an increase in the Chaco lowlands. Full article

Geological structures significantly influence mining-induced deformations in open-pit mines, with their variations and interactions adding complexity to the excavation process and introducing uncertainties in deformation outcomes. This study utilized numerical simulations to analyze the impact of weak rock zones in a specific open-pit limestone quarry in Japan on mining-induced deformation. The simulation results were both qualitatively and quantitatively validated against field measurements, enhancing the reliability of the findings. Subsequently, four conceptual models were developed based on the characteristics of the quarry to investigate the mechanisms by which weak rock zones affect rock slope deformations. Our analyses demonstrated that slip deformation occurred exclusively when two weak rock zones were connected. This deformation was associated not only with shear failure in the upper weak rock zone but also with the contraction and bending of the lower weak rock zone. Furthermore, the simulation results were consistent with field data and supported by the conceptual models, confirming that the proposed sliding mechanisms can effectively explain the observed deformation behaviors. The insights gained from these models provide valuable references for managing similar geological challenges in other open-pit mines. Full article

Although recent research suggests that the morphology and crustal structure of slow–ultraslow-spreading ridges are mainly controlled by melt supply, there is a lack of quantitative understanding of the effect of systematic changes in melt supply on the seafloor spreading state of mid-ocean ridges. In this study, we used bathymetry, free-air gravity anomaly, and sediment thickness data to calculate the residual bathymetry, mantle Bouguer gravity and crustal thickness of the Reykjanes Ridge. According to the gradient of changes in crustal thickness and residual bathymetry along the axis, the influence of melt supply on the spreading state of the Reykjanes Ridge can be divided into three zones: ultra-strong effect zone (0–160 km), strong effect zone (160–610 km), and weak effect zone (610–930 km). In the ultra-strong effect zone, excess melt supply and a higher melting degree result in a strong upwelling and large melt eruption. The change in relative position between the Reykjanes Ridge and the Iceland hotspot results in the spreading state of the Reykjanes Ridge transforming from asymmetric spreading to symmetric spreading. In the strong effect zone, the decrease in melt supply and melting degree weakens the mantle upwelling and enhances the viscosity of the dehydrated mantle layer. Sufficient viscosity of the dehydrated mantle layer forces asymmetric asthenosphere rise along the sloping boundary of the lithosphere, resulting in symmetric spreading. In the weak effect zone, the pattern of magma upwelling becomes a focused magma supply pattern similar to that of the slow–ultraslow-spreading of the mid-ocean ridge, and tectonics dominate the spreading process. The asymmetry of this weak effect zone may be due to the concentration of tectonic and magmatic activity on one flank of the ridge. Full article

The asymmetric excavation unloading activity of a rock slope with a fault has an important influence on the stability of the slope and the division of the surrounding surface influence area. Based on the engineering background of the West Open-Pit Mine in Fushun City, orthogonal testing, K-means clustering, range analysis, and variance analysis were used to study the linkage mechanism of the asymmetric excavation unloading action and the weak structure in the rock slope, as well as their effects on slope stability and the influence area. This analysis showed that the significant factors affecting the stability zones of the north and south slopes were the excavation inclination angles of the opposite slopes. When the excavation inclination of the north slope increased by 10 degrees, the safety factors decreased by 25.9% and 16.6%. When the excavation inclination of the south slope increased by 10 degrees, the safety factors decreased by 13.7% and 1.9%. A second significant factor was the excavation depth. The occurrence of faults in the slope was the main factor affecting the range of slope instability. In order to ensure production safety, the excavation inclination angle of a slope with a fault should be limited to no more than 40°, and the excavation depth of an unstable area with two slopes should be designed to be no more than 450 m. The influence of asymmetric excavation unloading on the stability of a rock slope with a fault structure is expounded. This also provides a theoretical basis for controlling slope stability and influence areas in large-scale open-pit mining projects. Full article