Soil Thickness Research Articles

Predicting the thickness of shallow landslides in Switzerland using machine learning

Abstract. Landslide thickness is a key variable in various types of landslide susceptibility models. In this study, we developed a model providing improved predictions of potential shallow-landslide thickness for Switzerland. We tested three machine learning (ML) models based on random forest (RF) models, generalised additive models (GAMs), and linear regression models (LMs). Next, we compared the results to three simple models that link soil thickness to slope gradient (Simple-S/linear interpolation and SFM/log-normal distribution) and elevation (Simple-Z/linear interpolation). The models were calibrated using data from two field inventories in Switzerland (HMDB with 709 records and KtBE with 515 records). We explored 39 different covariates, including metrics on terrain, geomorphology, vegetation, and lithology, at three different cell sizes. To train the ML models, 21 variables were chosen based on the variable importance derived from RF models and expert judgement. Our results show that the ML models consistently outperformed the simple models by reducing the mean absolute error by at least 20 %. The RF models produced a mean absolute error of 0.25 m for the HMDB and 0.20 m for the KtBE data. Models based on ML substantially improve the prediction of landslide thickness, offering refined input for enhancing the performance of slope stability simulations.

Identifying spatiotemporal pattern and trend prediction of land subsidence in Zhengzhou combining MT-InSAR, XGBoost and hydrogeological analysis

Zhengzhou city (China) experienced relatively significant land deformation following the July 20, 2021, extreme rainstorm (7·20 event). This study jointly utilised Multi-temporal synthetic aperture radar interferometry (MT-InSAR), eXtreme Gradient Boosting (XGBoost), and hydrogeological analysis to quantitatively assess the extent and trends, as well as the causes of land deformation before and after the 7·20 event in Zhengzhou city. The findings detected three major subsidence zones and two uplift zones within the city. The most significant subsidence occurred in the northern part of Zhongmu (− 28 mm/year), the northwest of Xingyang (− 16 mm/year), and the western region of Gongyi (− 6 mm/year). Conversely, a notable uplift was observed in the central city district (13 mm/year) and Xinzheng Airport (12 mm/year). The accuracy assessment of in-situ measurements (GNSS and levelling) yielded an overall root-mean-square error (RMSE) of 2.2 mm/year and an R-square of 0.948. Subsequently, the feature evaluation results based on the XGBoost method suggest that road density and precipitation are the dominant factors affecting land deformation in the entire study area or in the subsidence and uplift zones individually. Nevertheless, the other five factors (groundwater storage, soil type, soil thickness, NDVI, and slope) also act on land deformation individually and are intricately intertwined with each other. Furthermore, hydrogeological analysis from six groundwater wells reveals a synchronous relationship between groundwater level decline and land subsidence. The building load analysis shows a significant correlation between build-up density and subsidence rates, especially for those severe subsidence areas, with the maximum correlation coefficient reaching 0.6312. Finally, the geographic patterns analysis of post-event demonstrated a northeastward trend in land deformation, with a gradual reduction of deformation impact from 2018 to 2022.

Effects of interface roughness and layer thickness on the cracking characteristics of fine-grained coral soil

Fine-grained coral soil, prevalent in tropical shallow marine environments, demonstrates significant potential as a natural engineering material. This study presents laboratory experiments employing digital image technology to investigate the effects of soil layer thickness and interface roughness on its cracking characteristics. By analyzing soil particle displacement during the cracking process, we examined the relationship between particle movement and the observed macroscopic crack patterns. The results indicate that both interface roughness and soil thickness substantially influence crack development and morphology. Increased interface roughness accelerates the cracking rate and transforms the pattern from overall contraction to multi-directional expansion, resulting in dense crack networks. Thinner soil layers facilitate more intricate crack formations, whereas thicker layers lead to more pronounced settling, longer and wider cracks, reduced horizontal cracking, and a simplified overall cracking pattern. This study elucidates the impact of interface roughness and soil layer thickness on the cracking behavior of fine-grained coral soil, providing valuable insights for its potential engineering applications.

Seismic Mitigation Effect and Mechanism Analysis of Split Columns in Underground Structures in Sites with Weak Interlayers

The seismic damage of underground structures has been extensively investigated, and it has been demonstrated that underground structures located at weak interlayer sites are more prone to damage. In this study, a two-story two-span rectangular frame subway station structure is analyzed. A two-dimensional soil-underground structure model is developed using the large-scale finite element analysis software ABAQUS. The equivalent linear soil-underground structure dynamic time-history analysis method is employed to examine the seismic response of underground structures at weak interlayer sites. Variations in the thickness and shear wave velocity of the weak interlayer soil are analyzed. The seismic mitigation effects of split columns and prototype columns in underground structures at weak interlayer sites are systematically compared. The findings indicate that the relative displacement and internal force of key structural components significantly increase when the weak interlayer intersects the underground structure. Furthermore, as the thickness of the interlayer increases, the displacement and internal force also escalate. When the thickness of the weak interlayer remains constant and the shear wave velocity decreases, the relative displacement and internal force of the key structural components gradually intensify. Replacing ordinary columns with split columns substantially reduces the internal force of the middle column, providing an effective seismic mitigation measure for underground structures.

Extraction behavior of a modified suction caisson by reversely pumping water in layered soils

The suction caisson can be extracted for reuse by reversely pumping water after the decommissioning of offshore structures. Model tests were conducted to explore the modified suction caisson (MSC) extraction behavior by reversely pumping water. The results indicate that the MSC exhibits higher maximum over-pressure (MOP) but achieves smaller final extraction displacement (FED) in layered soils than in homogeneous soils. The MOP of the MSC in the clay over sand (t = 0.375, t is the ratio of the upper layer thickness to the total soil thickness) is 5.1, 7.6, and 4.5 times greater than that of the clay, sand, and sand over clay (t = 0.375), respectively. The FED of the MSC in the clay over sand (t = 0.375) is 71%, 60%, and 75% of the clay, sand, and sand over clay (t = 0.375), respectively. Furthermore, reversely pumping water into the internal caisson is better to achieve a higher FED in layered soils. In sand over clay, the MOP of the MSC decreases as t increases, while the FED initially decreases but then increases with t. In clay over sand, a specific upper clay thickness exists where the MSC results in the lowest FED.

Geology, Petrology and Geochronology of the Late Cretaceous Klaza Epithermal Deposit: A Window into the Petrogenesis of an Emerging Porphyry Belt in the Dawson Range, Yukon, Canada

Geologic understanding of the richly mineralized Dawson Range gold belt (DRGB) in the central Yukon, Canada is hindered by: (1) limited outcrop exposure due to thick soil cover; and (2) low resolution age-constraints despite a long history of porphyry Cu–Au–Mo deposit (PCD) exploration. Here, the well-preserved Klaza Au–Ag–Pb–Zn porphyry–epithermal deposit is used as a type-example of Late Cretaceous magmatic–hydrothermal mineralization to address the complex metallogeny of the DRGB. U–Pb zircon dating defines four magmatic pulses of Late Triassic to Late Cretaceous ages with the latter consisting of the Casino (80–72 Ma) and Prospector Mt. (72–65 Ma) suites. The Casino suite has five phases of intermediate-to-felsic calc-alkaline composition, correspond with older (77 Ma) porphyry mineralization, and displays evidence of magma mingling. The intermediate-to-mafic, slightly alkalic Prospector Mt. suite shows evidence of mingling with the youngest Casino suite phases, correlates with younger (71 Ma), intermediate-sulfidation epithermal and porphyry-type mineralization, and shoshonitic basalts of the Carmacks Group. Zircon trace element data suggest a common melt source for these suites; however, the younger suite records features (e.g., high La/Yb) that indicate a higher pressure melt source. The results from this study highlight the Prospector Mt. suite as a historically overlooked causative magma event linked to Au-rich PCDs in the DRGB and extends the temporal window of PCD prospectivity in this area. The transition from mid-Cretaceous Whitehorse suite magmas to Late Cretaceous Casino-Prospector Mt. suite magmas is proposed to reflect a transition from subduction to localized extension, which is becoming more recognized as a common characteristic of productive porphyry belts globally.

NUMERICAL MODEL ANALYSIS OF SUBGRADE SETTLEMENT WITH FOAM MORTAR REINFORCEMENT BASED ON THICKNESS VARIATION

Soft soils have low bearing capacity characteristics and can cause high settlement. Sub grade which becomes the lowest layer in road construction is expected to have a strong bearing capacity so that it can carry the construction load on it. To overcome this problem, it is necessary to reinforce it. Problems will arise if the thickness of the soft soil in the subgrade varies. So, it needs to know and identify the scale of declining that occurs if the soft soil variation is reinforced on it. Foam mortar is an alternative reinforcement that is expected to improve the properties of the soft soil. The purpose of this research is to analyze the soft soil embankment model using foam mortar reinforcement against variations in soft soil height. The method of analysis was carried out by numerical method of Plaxis 2D version 2023. The geometric model in this study with foam mortar thickness of 30 cm was varied against subgrade layer height of 60 cm, 120 cm and 180 cm. The modeled load is a centralized load with variations of 0, 10, 20, 40, 60, 80, 100 and 120 kN. Numerical results obtained the highest settlement occurred at 180 cm soft soil layer of 0.01421 mm. The largest deformation occurred in the soft soil layer of 1,461 x 10-3 mm. In conclusion, the thicker the soft soil layer, the higher the settlement and the greater the deformation.

Improving regulation of the use of soils and subsoils dumps in the Russian Federation

The analysis of the practice for regulating the use of dumps of soils and subsoils in the Russian Federation is carried out. It is shown that the existing regulations do not meet modern requirements for the protection and rational use of dumps of soils and subsoils. The absence of a unified recycling approach has been revealed. In some regulatory documents, dumps of soils and subsoils are considered as material for the reclamation of disturbed lands, in others – as industrial waste. Disagreement with the practice of classifying all dumps of soils and subsoils as waste of hazard classes 3–5 and subject to export to special polygons is justified. Disposal of such waste materials is administratively or criminally punishable. This approach to the material of soil excavation causes great harm to both the economy and the environment as a whole. It is proposed to change the practice of irrational use of soil and subsoil dump material and make appropriate changes to regulatory documents. One of such changes may be the introduction of the gradation “environmentally safe waste” into the documents on the definition of the hazard class of waste, with the prescription for the use of soil and subsoil dumps belonging to this category without restrictions on use in the national economy. It is proposed to clarify the magnitude of the soil thickness (soil layer) of 5 m, including the maximum depth of occurrence of fertile soil layer and potentially fertile layer. This value corresponds to the accepted stratigraphic rule on the general regularity of the structure of the sedimentary shell of the Earth. According to this point of view, soils are underlain by subsurface geological rocks, which does not imply the presence of intermediate geological layers between soils and subsurface.

Re-examination and analysis of test data on consolidation of soft soils exhibiting creep with different thicknesses

Accurate prediction regarding the long-term settlements of soft soils is challenging. One of the reasons for this is time-dependent soil behaviours. How to extrapolate such behaviours from thin laboratory testing with limited timescales to an in situ thick soil layer with large timescales is still an ongoing debate, which can be dated back to the work of Ladd and co-workers in 1977. Many experimental results that were previously used to advocate hypothesis A have been re-analysed and found to align with hypothesis B. However, discrepancies remain in some historical data, particularly in the case of Osaka clay retrieved from the seabed under the Kansai international airport islands. This study begins by introducing the main implications and selected existing models for the time-dependent behaviours of soft soil. It then focuses on the re-examination of selected test results from the work of Watabe and co-workers in 2008, supplemented by numerical simulation using isotache models. The analysis emphasises the importance of considering equal initial conditions when comparing data from samples with varying thicknesses. Furthermore, the good agreement observed between measured data and the simulation results using hypothesis B methods demonstrates the validity of hypothesis B for predicting the long-term consolidation behaviour of soft soil both in the laboratory and at field scales.

Development of an educational software for the assessment of natural slope stability

The analysis of natural slope stability is critical for reducing or mitigating potential catastrophic risks associated with landslides. This kind of disaster not only generates substantial economic and material losses but also creates significant threats to human safety. Landslides occur when forces acting down-slope exceed the soil strength of slopes. In particular, critical factors such as the slope gradient and the thickness of the soil layer can increase such forces, making a slope prone to sliding. Another cause for landslides is rainfall because it can increase the forces acting in the slope (such as the soil weight) or reduce the soil strength (such as the soil cohesion and friction angle), in particular under unsaturated conditions. The deterministic approaches based on numerical or limit equilibrium methods are used to check slope stability through the computation of the Factor of Safety (FOS). However, the impact of the slope geometric features, soil properties or rainfall cannot be assessed unless sensitivity studies are carried out, making difficult the learning process of slope stability. Therefore, in this study, we introduce an educational software for the quick assessment of FOS in natural slopes. The application allows the analyses of FOS considering input data such as 3D declivity maps, soil thickness, soil properties and rainfall intensity. The application boasts user-friendly navigation and delivers real-time results, enabling sensitivity analyses of the safety factor concerning parameters, alongside risk appraisal and prognostication of local condition changes following rainfall episodes.

Climate, soil, and viticultural factors differentially affect the sub-regional variations in biochemical compositions of grape berries

Climate, soil, and viticultural factors differentially affect the sub-regional variations in biochemical compositions of grape berries

The Effects of Fire Intensity on the Biochemical Properties of a Soil Under Scrub in the Pyrenean Subalpine Stage

Fire causes changes in many soil attributes, depending on multiple factors which are difficult to control in the field, such as maximum temperature, heat residence time, charred material incorporation, etc. The objective of this study is to evaluate the effect of a gradient of fire intensities on soils at the cm scale. Undisturbed topsoil monoliths were sampled under scrubs in the subalpine stage in the Southern Pyrenees (NE Spain). They were burned, under controlled conditions in a combustion tunnel, to obtain four charring intensities (CIs), combining two temperatures (50 and 80 °C) and two residence times (12 and 24 min) reached at 1 cm depth from the soil. Unburned soil samples were used as a control. All soils were sampled, cm by cm, up to 3 cm deep. The following soil properties were measured: soil respiration (basal, bSR and normalized, nSR), β-D-glucosidase (GLU), microbial biomass carbon (MBC), glomalin-related soil proteins (GRSPs), soil organic carbon (SOC), labile carbon (DOC), recalcitrant organic carbon (ROC), total nitrogen (TN), soil pH, electrical conductivity (EC) and soil water repellency (SWR). Even at low intensities, GLU, SOC and total GRSP were significantly reduced and, conversely, SWR was enhanced. At the higher CIs, additional soil properties were significantly reduced (MBC and C/N) or increased (DOC, ROC, nSR, easily extractable GRSP). This study demonstrates that there is a differential degree of thermal sensitivity in the measured biochemical soil properties. Furthermore, these properties are more affected at 0–1 cm than at 1–2 and 2–3 cm soil thicknesses.

Integrated geophysical investigations of groundwater for sustainable management in Faisalabad region of Pakistan

As global and local populations surge and climate change continue to disrupt surface and groundwater reservoirs, the urgent need arises to explore additional groundwater sources. Ensuring sustainable management necessitates the efficient identification of high-potential zones to meet escalating water demands. This study aims to delineate groundwater potential zones in Faisalabad District, Pakistan, utilizing a cost-effective geoelectrical resistivity survey method. Apparent resistivity data was collected using the Schlumberger electrode configuration and analyzed with the Interpex “IX1D v2 model” to determine true soil layer resistivities and thicknesses with average root mean square error of 5.12%. The results have revealed that the Aquifer thickness ranged from 13.35 to 165.59 m, and resistivity from 23.96 to 1125.0 Ωm. Hydraulic conductivity, transmissivity, and porosity of aquifers varied from 0.49 to 24.11 m/day (average 8.214 m/day), 35.67 to 1593.98 m2/day (average 567.771 m2/day), and 22.29 to 39.82% (average 37.465%), respectively. Integration of resistivity and geo-hydraulic properties data identified vertical electrical sounding (VES) points 1, 3, 4, and 6 as highly suitable for large-scale freshwater extraction due to having high groundwater potential repositories (coarse sand and gravel formations). Other points had varying suitability: VES points 7 and 8 for shallow wells only, VES points 5, 9, and 10 not recommended due to hard formations, and VES point 2 due to poor groundwater quality. This integrated approach has proven effective in assessing groundwater strata to support Sustainable Development Goal (SDG-3), making it applicable to other geographic locations and informing policy decisions for effective groundwater management.

Ecological analysis of the structure and dendrometric characteristics of the population of Juniperus thurifera: a vulnerable species

ABSTRACT Juniperus thurifera was selected for this study due to its crucial ecological role in high mountain ecosystems and the increasing threats it faces, such as habitat degradation and regeneration challenges. The analysis of stand structure by altitude shows that the distribution of individuals and stem count vary with elevation, highlighting the species’ adaptability to mountainous conditions. Altitudinal degradation significantly impacts seed production, with a positive correlation (r = 0.65) between stem and fruit numbers in females. J. thurifera also plays a vital role in soil retention, as indicated by the positive correlation (r = 0.511) between ground projection and soil thickness, emphasizing its importance in slope stabilization and erosion prevention. Sexual dimorphism reveals dendrometric differences between males and females, affecting regeneration and reproduction. Age estimation based on circumference shows the predominance of aging, non-reproductive trees, threatening future regeneration. Principal component analysis (PCA) further refines recommendations by revealing complex relationships between dendrometric characteristics and environmental factors, providing precise guidelines for J. thurifera conservation.

Numerical study of rainfall percolation through a novel capillary barrier cover with a zipper-shape interface between fine- and coarse-grained soils

The huge amount of leachate generated in landfills causes persistent pollution to soil and groundwater. Landfill cover is vital for reducing leachate generation through reducing rainwater infiltration. Yet, the traditional cover with capillary barrier effects (CCBE) is only applicable in reducing rainwater percolation at its base in arid or semi-arid region. To solve this problem, a novel capillary barrier cover is proposed, which adds multiple gravel-segments to the traditional CCBE to form the zipper-shape interface between fine- and coarse-grained soils. Hydraulic response of this zippered CCBE is numerically investigated considering different gravel-segment sizes, drainage-ditch widths and climate conditions. It is found that the zippered CCBE has a lower water percolation than the traditional one by up to 57%. It is because the capillary barrier effects along the right side-wall of gravel-segment leads to water accumulation and hence water percolation near its base, facilitating reducing water percolation using drainage ditch below the gravel-segment. Moreover, water percolation increases when the gravel-segment height exceeds 0.3 times thickness of fine-grained soil or the gravel-segment width increases, due to reduction of water storage in fine-grained soil. Under the recorded annual precipitation of 1235mm in the semi-humid region in China, the annual percolation of the traditional and zippered CCBEs are 84mm/year and 36mm/year, respectively. Thus, the zippered CCBE might extent the applicability of the traditional CCBE from arid or semi-arid region to semi-humid region.

Binary response of runoff generation and erosion processes to karst vegetation-soil-rock structure and its hydrodynamic mechanisms

Binary response of runoff generation and erosion processes to karst vegetation-soil-rock structure and its hydrodynamic mechanisms

Translating mineral systems criteria into a prospectivity model for IOCG deposits in the Kolari region, Finland

Translating mineral systems criteria into a prospectivity model for IOCG deposits in the Kolari region, Finland

Advances in Cold-Climate-Responsive Building Envelope Design: A Comprehensive Review

Extreme low temperatures, heavy snowfall, ice accumulation, limited daylight, and increased energy consumption in cold climates present significant challenges but also offer opportunities for improving building efficiency. Advanced materials and technologies in climate-responsive envelopes can enhance sustainability, reduce carbon footprints and operational costs, and improve thermal comfort under these environmental conditions. This literature review combines theoretical aspects of building performance in cold climates with a summary of current and critical applications in building envelope design, identifying research gaps and proposing future research directions. It has been shown that various BIPV systems require further climate-based studies to optimize solar energy yield. For example, integrating PV layers and PCM within DSFs can reduce cooling loads, but more research is needed on PCM transition temperatures and ventilation strategies in cold climates. A notable research gap exists in building-integrated vegetative systems, particularly regarding soil thickness, irrigation, hygrothermal performance, and snow accumulation. Despite excellent winter performance in buildings incorporating CLT components, they face increased cooling energy consumption and potential overheating in summer. Additionally, the high initial moisture content in CLT raises the risk of mold growth, especially when covered with vapor-tight layers. The design examples in this paper emphasize the need for further investigation to achieve sustainable, low-carbon, energy-efficient envelope designs for cold climates.

Seismic Stability Evaluation of Landfill Veneer Cover Systems Using Modified Pseudo-Dynamic Method

ABSTRACT This study evaluates the seismic stability of veneer cover systems, addressing the sliding failure (SF) and uplifted-floating failure (UF) caused by retained water. The modified pseudo-dynamic (MPD) method, considering hydrostatic, hydrodynamic, and seismic forces, is employed. Comparison of the results with the literature under the pseudo-static (PS) and pseudo-dynamic (PD) loading conditions highlight the precision of the MPD method. Consideration of the visco-elastic behavior and soil damping in the analysis enhances the accuracy of the MPD method. Design charts are proposed for the determination of the allowable thickness of cover soil, which is cost-effective, ensuring seismic safety against SF and UF modes.

Productive conservation at the landslide prone area under the threat of rapid land cover changes

Abstract Landslides often occur in the study area as a continuation of the erosion process on very thick soil from a series of volcanic ash deposition during the Tertiary and Quaternary periods. Rapid land cover changes from agricultural land into settlement increase runoff significantly causing accelerated soil erosion. Soil conservation approaches using parameters to reduce surface runoff and soil loss are less acceptable in agricultural society. Soil conservation methods aimed at reducing runoff and soil loss are not widely embraced in agricultural communities, efforts in soil conservation must be economically beneficial. Vegetative-based erosion control is the most suitable option for the agricultural communities. However, there needs to be improvements in terms of plant arrangement that is adapted to the spatial arrangement of slopes and is focused on zones along rills and gullies. Selection of tree species planted for erosion control that have the value of increasing economic income is the key to the success of planned soil and water conservation efforts.