In the dynamic response analysis of slopes, the displacement of sliding surfaces is an important indicator for assessing stability. However, due to the uniform dynamic parameters of the Newmark slide block method, it is difficult to accurately analyze the displacements of large-scale slopes. To address this issue, the spatial distribution characteristics of dynamic parameters need to be considered to accurately analyze the stability of slopes. Under the combined action of rainfall and reservoir water level change, the Shiliushubao old landslide in the Three Gorges Reservoir area remains stable. To investigate the seismic stability of slopes, simulated seismic waves were employed. Firstly, the dynamic triaxial test, designed with cyclic loading, was employed to investigate the variation rules of the dynamic parameters of slope soil, and to establish a functional relationship. Then, the stochastic seismic motion model was used to generate artificially seismic waves in the Three Gorges Reservoir Area. Finally, to assess the stability of the old landslide, finite element software, GeoStudio 2018 was used to obtain the spatial distribution characteristics of the dynamic parameters and to calculate the permanent displacements of the reservoir bank slope by inputting random ground motion loads and dynamic characteristic functions. It is demonstrated that under the most unfavorable working conditions of heavy rainfall and the earthquake in the specific region, the permanent displacement of the Shiliushubao old landslide will be less than the critical permanent displacement, the old landslide is not to experience instability again.

On December 18, 2023, an Ms6.2 earthquake struck Jishishan County, Gansu Province, in western China. The China Earthquake Early Warning Network (CEEWN) captured extensive near-field ground motion data using high-density microelectromechanical system (MEMS) sensors and force-balanced accelerographs (FBAs). Through noise level and usable frequency range assessments of MEMS/FBA recordings, we compiled a strong- motion dataset encompassing the Ms6.2 mainshock and 13 aftershocks (Ms >= 3.0). Analysis of this dataset revealed distinct source characteristics and site effects through spatial distributions and attenuation patterns of peak ground acceleration (PGA, up to 1.1 g at station N002B), peak ground velocity (PGV), and spectral accelerations (SAs) across various periods. The mainshock's near-fault motions exhibited pronounced short-period energy, with 0.2 s SAs exceeding 1.0 gin intensity zones VII-VIII due to hanging wall effects, soil amplification, and topographic influences. Site-to-reference ratio (SSR) analysis identified site nonlinearity above 1 Hz and amplification between 1 and 10 Hz. Observed PGAs and short-period SAs surpassed ground motion model (GMM) predictions with faster attenuation rates, while long-period SAs (>1.0 s) remained below predictions. Residual analysis of intensity measures (IMs) and horizontal-to-vertical spectral ratios (HVSRs) demonstrated progressive site nonlinearity, showing HVSR frequency reductions and amplitude declines at PGAs >500 cm/s(2). This dataset advances regional ground motion model (GMM) development, while our findings on strong ground motion characteristics offer critical insights for earthquake damage assessment and post-disaster reconstruction.

The spatial combination of stratigraphic structural elements significantly influences the overburden damage caused by mining. However, existing studies have not yet clearly revealed the specific relationship between these elements and overburden damage, nor have they intuitively demonstrated the spatial distribution characteristics of overburden damage. In response, this paper proposes a comprehensive analysis method that can visually and quantitatively characterize the spatial distribution of overburden damage. This method combines stratigraphic model generalization, damage mechanics modeling, numerical simulation, and color mapping characterization. This method was applied to analyze the mining damage characteristics of different structural overburdens in the Yushenfu mining area. The analysis revealed a prevalent stratigraphic combination pattern of sand layers, soil layers, and two sections of mudstone and fine sandstone interbeds. The study shows that mining height and bedrock-soil ratio are important stratigraphic structural factors that affect the fracture/mining height ratio. The ranking of elastic modulus loss and spatial loss in various damaged areas of the overburden is consistent, in the following order: collapse zone > fracture zone > bending subsidence zone. Furthermore, this method reveals the mechanism of increased residual expansion in the overburden caused by coal mining, which, in turn, leads to surface collapse. This method provides a theoretical basis for implementing targeted engineering disposal and safety measures.

The spatial distributions of hydraulic conductivity and shear strength parameters are influenced by the soil structure, property and mineral composition. However, hydraulic conductivity is not only determined by the intrinsic soil property but also influenced by external factors such as fractures and interlayers. This study investigates the impact of the asynchronism between the spatial distribution of hydraulic conductivity and shear strength parameters on the reliability assessment and failure mechanism of unsaturated soil slopes with different titled stratifications under rainfall conditions. The results indicate that the asynchronism in the rotational angles (alpha) of hydraulic conductivity and shear strength parameters shows the greatest impact on the probability of failure (Pf) of slopes. By contrast, the asynchronism in the scales of fluctuation of hydraulic conductivity and shear strength parameters and employing different autocorrelation functions (ACFs) show minor impact on the Pf. The impact of using different ACFs, alpha, and scales of fluctuation to characterise the spatial variability of hydraulic conductivity on sliding mass and failure modes is minimal.

In the construction of slurry shield tunneling, the infiltration of slurry will cause excess pore water pressure in the surrounding soil. The distribution of excess pore water pressure and slurry infiltration zone are closely related to the stability of the tunnel face. Considering the influence of cutter head rotation and slurry specific gravity on pressure boundary conditions, this study proposed a multi-field coupling model to describe the dynamic transmission of excess pore water pressure and distribution of slurry infiltration range in three-dimensional. The temporal and spatial variation of soil pores characteristics parameters and slurry rheological properties owing to the deposition and diffusion of slurry particles is considered. The proposed model is verified by the in-situ testing measurements from in Beijing East Sixth Ring Road reconstruction project. In the prediction results, the spatial distribution of excess pore water pressure around the tunnel face appears bubble-shaped, and the shape of the slurry infiltration zone is close to flattened cake. The range of pressure dissipation and the thickness of particles infiltration zone are positively correlated with soil permeability coefficient, slurry pressure, while negatively correlated with the mass concentration of slurry. In the cases of low-permeability soil, appropriately increasing the content of slurry particles can improve the compactness of the filter cake.

Spatial distribution orientations of blocks can cause significant errors in the discrete element model (DEM) calculation of soil-rock mixture (SRM). To avoid this error, spherical harmonic (SH) series whose harmonization degrees fixed at 15 were proposed for block reconstruction. This research refers to the case-history of a deep excavation rift valley spanning from the Mabian to Zhaojue of the Leshan-Xichang Expressway, mainly containing moderately-weathered silty mudstone, in the Leshan City, Sichuan Province, China. The appropriate degree of finite-term SH series is selected by the volume, surface area. 100 blocks were scanned on site, and sphericity and angularity of the blocks were calculated. The sphericity and angularity of 50 reconstructed blocks were considered for the error analysis of SH method. Moreover, stochastic polyhedron method was considered for comparing different block reconstructions. The maximum block placement angle was defined to control the spatial distribution orientations of the blocks. Large scale direct tests were carried. Numerical simulations of large-scale direct shear tests were conducted to study the influence of the spatial distribution orientations of the blocks on the mechanical properties of the SRMs. The results revealed that the finite-term SH series fixed at 15 accurately reflected the shape characteristics and mechanical behaviors of actual blocks. The spatial distribution orientations of the blocks had a minimal impact on the friction angle and cohesion of SRM constructed through the SH method. The SRMs developed via the SH method exhibited marginal variations in contact force and anisotropy index of contact across diverse block placement strategies. The evolution of coordination number was closer when employing the SH method under varied block placement methods. Blocks reconstructed by the SH method, could mitigate errors in DEM calculation caused by the spatial distribution orientations of the blocks.

The more insects there are, the more food there is for insectivores and the higher the likelihood for insect-associated ecosystem services. Yet, we lack insights into the drivers of insect biomass over space and seasons, for both tropical and temperate zones. We used 245 Malaise traps, managed by 191 volunteers and park guards, to characterize year-round flying insect biomass in a temperate (Sweden) and a tropical (Madagascar) country. Surprisingly, we found that local insect biomass was similar across zones. In Sweden, local insect biomass increased with accumulated heat and varied across habitats, while biomass in Madagascar was unrelated to the environmental predictors measured. Drivers behind seasonality partly converged: In both countries, the seasonality of insect biomass differed between warmer and colder sites, and wetter and drier sites. In Sweden, short-term deviations from expected season-specific biomass were explained by week-to-week fluctuations in accumulated heat, rainfall and soil moisture, whereas in Madagascar, weeks with higher soil moisture had higher insect biomass. Overall, our study identifies key drivers of the seasonal distribution of flying insect biomass in a temperate and a tropical climate. This knowledge is key to understanding the spatial and seasonal availability of insects-as well as predicting future scenarios of insect biomass change.

The damage caused by petroleum hydrocarbon pollution to soil and groundwater environment is becoming increasingly significant. The vadose zone is the only way for petroleum hydrocarbon pollutants to leak from surface into groundwater. The spatial distribution characteristics of indigenous microorganisms in vadose zone, considering presence of capillary zones, have rarely been reported. To explore the spatial distribution characteristics of indigenous microorganisms in vadose zone contaminated by petroleum hydrocarbons, a onedimensional column migration experiment was conducted using n-hexadecane as characteristic pollutant. Soil samples were collected periodically from different heights during experiment. Corresponding environmental factors were monitored online. The microbial community structure and spatial distribution characteristics of the cumulative relative abundance were systematically analyzed using 16S rRNA sequencing. In addition, the microbial degradation mechanism of n-hexadecane was analyzed using metabolomics. The results showed that presence of capillary zone had a strong retarding effect on n-hexadecane infiltration. Leaked pollutants were mainly concentrated in areas with strong capillary action. Infiltration and displacement of NAPL-phase pollutants were major driving force for change in moisture content ( theta) and electric conductivity (EC) in vadose zone. The degradation by microorganisms results in a downward trend in potential of hydrogen (pH) and oxidation reduction potential (ORP). Five petroleum hydrocarbon -degrading bacterial phyla and 11 degradable straightchain alkane bacterial genera were detected. Microbial degradation was strong in the area near edge of capillary zone and locations of pollutant accumulation. Mainly Sphingomonas and Nocardioides bacteria were involved in microbial degradation of n-hexadecane. Single -end oxidation involved microbial degradation of n-hexadecane (C 16 H 34 ). The oxygen consumed, hexadecanoic acid (C 16 H 32 O 2 ) produced during this process, and release of hydrogen ions (H + ) were the driving factors for reduction of ORP and pH. The vadose zone in this study considered presence of capillary zone, which was more in line with actual contaminated site conditions compared with previous studies. This study systematically elucidated vertical distribution characteristics of petroleum hydrocarbon pollutants and spatiotemporal variation characteristics of indigenous microorganisms in vadose zone considered presence of capillary zone. In addition, the n-hexadecane degradation mechanism was elucidated using metabolomics. This study provides theoretical support for development of natural attenuation remediation measures for petroleum -hydrocarbon -contaminated soil and groundwater.

Mining activities have a positive impact on the global economy by increasing the socio-economic impact of the country's economic growth. However, they pose a high environmental risk of damaging sediments, and aquatic ecosystems by accumulating potentially toxic elements. Located in northern Tunisia, Oued Kasseb is one of the outlets of the Medjerda River, Tunisia's main watercourse and a major source of irrigation and drinking water. Oued Kasseb is the nearest watercourse to the Pb-Zn mining district of Djebel Hallouf-Sidi Bouaouane, a century-old mine (1890-1986). This study focuses on evaluating the spatial distribution of heavy metals (arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn)), their degree of contamination, using pollution indices, and on assessing the ecological and human health risks posed in the Oued Kasseb study area. The obtained heavy metal concentrations were in the following order: Pb > Zn > As > Cr > Ni > Cu > Cd. The spatial distribution shows that relatively high concentrations of metals were found in the vicinity of the Pb-Zn abandoned mine. The geoaccumulation index (I geo), the enrichment factor (EF), the contamination factor (CF), and the potential ecological risk index (RI) showed that the sediments are highly contaminated with As, Cd, Pb, and Zn, especially for sites surrounding the mine. The statistical analysis shows that As, Cd, Cu, and Pb are correlated strongly with Zn and appeared in the first component (F1:70.89%). The noncancerogenic risk revealed that As damages the children whereas it is not harmful to the adult group. The abandoned Pb-Zn mines are therefore the main source of heavy metals in the Oued Kasseb, causing serious environmental pollution and posing significant health risks.

Soil water content (SWC) and soil temperature (ST) are important indicators of environmental change in permafrost regions. In this study, we conducted soil sampling at 89 locations in the Three Rivers Headwaters Region (TRHR) to investigate the individual and synergistic effects of environmental factors on SWC and ST. We used multivariable regression and random forest modelling to analyse the data. The results show that SWC and ST were higher in the southeast TRHR than in the northwest and higher in surface layers than deeper soil layers. The most important factors affecting SWC in the 0-20 cm and 20-40 cm soil layers were soil bulk density and precipitation, while bulk density was the most important factor in the 40-60 cm layer, and soil bulk density and steppe vegetation were the most important factors in the 60-80 cm layer. For ST, altitude, temperature and slope gradient were the drivers in the 0-20 cm surface layer, while altitude and temperature were the most critical drivers in the 20-40 cm, 40-60 cm and 60-80 cm layers. Overall, bulk density and altitude were the key environmental factors influencing SWC and ST values, respectively. The outcomes of this study provide valuable insights into the environmental factors that impact the SWC and ST in permafrost regions, which can guide decision-making processes for sustainable soil management in the context of climate change.