On December 18, 2023, a magnitude MS6.2 earthquake struck Jishishan County, Gansu Province, triggering over 40 seismic subsidence sites within a seismic intensity VI zone, 32 km from the epicenter.The earthquake caused tens of millions in economic losses to mountain photovoltaic power stations. Extensive geological surveys and comparisons with similar landslides (such as soil loosening, widespread cracks, and stepped displacements) triggered by the 1920 Haiyuan MS8.5 earthquake and the 1995 Yongdeng MS5.8 earthquake, this study preliminarily identifies one subsidence sites as a seismic-collapsed loess landslide. To investigate its disaster-causing mechanism: the dynamic triaxial test was conducted to assess the seismic subsidence potential of the loess at the site, and the maximum subsidence amount under different seismic loads were calculated by combining actual data from nearby bedrock stations with site amplification data from the active source; simulation of the destabilization evolution of seismic-collapsed loess landslides by large-scale shaking table tests; and a three-dimensional slope model was developed using finite element method to study the complex seismic conditions responsible for site damage. The research findings provide a theoretical foundation for further investigations into the disaster mechanisms of seismic-collapsed loess landslides.

Chromium is a heavy metal used in tanneries, leather industries, electroplating, and metallurgical operations, but improper disposal of waste from these industries leads to environmental contamination. Chromium exists primarily in trivalent and hexavalent forms, with hexavalent chromium (Cr (VI)) being highly toxic. Cr (VI) is carcinogenic, damages fish gills, and negatively impacts crops. Considering these negative impacts of Cr (VI), several physical, chemical, and biological remediation methods have been implemented at contaminated sites, but in most instances, these methods could be uneconomical, highly labor-intensive, and not sustainable. Therefore, a crucial goal is to implement an effective and sustainable remediation technique with consideration of actual site conditions. The aim is to develop a sustainable remediation strategy for a hexavalent chromiumcontaminated site in Ranipet, Tamil Nadu. The comprehensive risk assessment for the site has depicted hazard quotients greater than 1 for both onsite and offsite conditions, indicating the necessity of remediation. To address this, it is suggested to build permeable reactive filters (PRFs) packed with scrap iron filings to reduce Cr (VI) to Cr (III), and succeeding filters with locally produced waste coconut shell biochar to aid in adsorption. The use of waste here aims to eliminate the need to procure any commercially available materials for remediation, completely cutting down the environmental impact of raw material extraction or processing. A continuous chambered set-up packed with contaminated soil and PRFs with biochar and iron filings aided in the decrease of the peak concentration of Cr (VI) by 61 % as compared to a set-up without intervention. Moreover, the outlet concentration after 7 days reduced to 0.08 mg/L, which was 97.6 % less than that in the set-up without intervention.

The exploration of the Moon necessitates sustainable habitat construction. Establishing a permanent base on the Moon requires solutions for challenges such as transportation costs and logistics, driving the emphasis on In-Situ Resource Utilization (ISRU) techniques including Additive Manufacturing. Given the limited availability of regolith on Earth, researchers utilize simulants in laboratory studies to advance technologies essential for future Moon missions. Despite advancements, a comprehensive understanding of the fundamental properties and processing parameters of sintered lunar regolith still needs to be studied, demonstrating the need for further research. Here, we investigated the fundamental properties of lunar regolith simulant material with respect to the stereolithography-based AM process needed for the engineering design of complex items for lunar applications. Material and mechanical characterization of milled and sintered LHS-1 lunar regolith was done. Test specimens, based on ASTM standards, were fabricated from a 70 wt% (48.4 vol %) LHS-1 regolith simulant suspension and sintered up to 1150 degrees C. The compressive, tensile, and flexural strengths were (510.7 +/- 133.8) MPa, (8.0 +/- 0.9) MPa, and (200.3 +/- 49.3) MPa respectively, surpassing values reported in previous studies. These improved mechanical properties are attributed to suspension's powder loading, layer thickness, exposure time, and sintering temperature. A set of regolith physical and mechanical fundamental material properties was built based on laboratory evaluation and prepared for utilization, with the manufacturing of complex-shaped objects demonstrating the technology's capability for engineering design problems.

This study explored the effects of forest fires on soil microbial activity in forest soils classified by rock origin (igneous, metamorphic, and sedimentary) and stratified by subsoil depth (topsoil, subsoil). Microbial activity, indicated by average well color development (AWCD) and Shannon diversity indices, was higher in undamaged topsoils compared to fire-damaged ones. In contrast, fire-damaged subsoils, particularly in metamorphic and sedimentary soils, exhibited increased microbial activity over time due to organic matter decomposition. A significant increase in substrate utilization was observed in undamaged soils across all rock types (*p < 0.05, **p < 0.01) in topsoil, with sedimentary rock exhibiting the highest microbial diversity based on Shannon indices. The dehydrogenase activity followed a similar pattern, with reduced activity in fire-damaged topsoil but higher activity in damaged metamorphic and sedimentary subsoils. Principal component analysis (PCA) linked microbial indicators (AWCD, Shannon index) to mineral compositions like orthoclase and hornblende, highlighting the role of soil chemistry in shaping microbial responses to fire. These insights advance the understanding of fire-induced changes in soil microbial functions across diverse geological contexts.

Industrial development has caused significant environmental damage, especially through potentially toxic element (PTE) pollution. Combining pollution indices, health risk assessment, spatial autocorrelation (Moran's I), and receptor modeling (APCS/MLR), this study quantified sources and risks of heavy metals in smelting-adjacent farmland soils, facilitating targeted PTE pollution mitigation. Soil analysis revealed significantly elevated mean concentrations of As (326 mg/kg), Cd (23 mg/kg), Cr (104 mg/kg), Cu (106 mg/kg), Ni (73 mg/kg), Pb (274 mg/kg), and Zn (660 mg/kg), all exceeding Yunnan provincial background values. The average total non-carcinogenic risk index (HIadult = 2, HIchild = 11) and total carcinogenic risk index (TCRadult = 5.52 x 10-4, TCRChild = 6.44 x 10-4) for both adults and children exceeded the threshold (HI = 1, TCR = 1 x 10-04). The results of environmental pollution evaluation show that the overall pollution in the study area is a heavy pollution level. The ACPS-MLR model showed that Cd and Zn in soil mainly came from industrial activities (37%). Cu and Pb were derived from motor vehicle emissions and agricultural activities (20%). As may be derived from agricultural and industrial activities. Furthermore, based on the combination of source apportionalization and the spatial distribution of environmental pollution, the northeastern part of the study area and transportation hubs are the key pollution areas and need to be given priority for treatment. PTEs accumulate in the soil, will be enriched through the food chain, and seriously threaten human health and soil ecological environment. Therefore, this study can provide a basis for identifying, preventing, and controlling the risk of PTEs pollution in soil.

While numerous studies have examined pollution sources and seasonal effects on surface water quality independently, the complex interactions between these factors remain understudied. This research aimed to fractionate and quantify pollution sources and examine their interactive effects with seasonal variations on surface water quality in Khanh Hoa, Vietnam. The current study was based on 1080 surface water samples taken from three common water bodies - lakes, rivers, and canals across dry and rainy seasons and analyzed for 13 physiochemical properties. Findings revealed that surface water quality was influenced by four primary pollution sources: agricultural activities, residential areas, onsite erosion, and climatic factors. Agricultural sources dominated canal water quality (93.0-94.7%) but had less impact on lakes and rivers (12.8-23.8%). Residential sources significantly affected lakes and rivers (30.23-32.66%) but minimally influenced canals (2.6-5.6%). Onsite erosion sources had greater impacts on lakes and rivers typically during the rainy season and exhibited minimal impacts on canals. Lakes and rivers maintained consistent and higher water quality across seasons (water quality index (WQI) 9.1 to 9.3 out of 1.0 - excellent), while canals exhibited substantially lower quality in the dry season (WQI 0.75) compared to the rainy season (WQI 0.78). These interactive impacts were mitigated by self-purification, water residence time in lakes and rivers, dilution effects, and fast pollutant transport in canals. Our findings highlight the importance of effective management of these key pollution sources in interaction with seasonal variation for maintaining water quality and ensuring environmental sustainability.

Accurately understanding flood evolution and its attribution is crucial for watershed water resource management as well as disaster prevention and mitigation. The source region of the Yellow River (SRYR) has experienced several severe floods over the past few decades, but the driving factor influencing flood volume variation in the SRYR remains unclear. In this study, the Budyko framework was used to quantify the effects of climate change, vegetation growth, and permafrost degradation on flood volume variation in six basins of the SRYR. The results showed that the flood volume decreased before 2000 and increased after 2000, but the average value after 2000 remained lower than that before 2000. Flood volume is most sensitive to changes in precipitation, followed by changes in landscape in all basins. The decrease in flood volume was primarily influenced by changes in active layer thickness in permafrost-dominated basins, while it was mainly controlled by other landscape changes in non-permafrost-dominated basins. Meanwhile, the contributions of changes in potential evapotranspiration and water storage changes to the reduced flood volume were negative in all basins. Furthermore, the impact of vegetation growth on flood volume variation cannot be neglected due to its regulating role in the hydrological cycle. These findings can provide new insights into the evolution mechanism of floods in cryospheric basins and contribute to the development of strategies for flood control, disaster mitigation, and water resource management under a changing climate.

Understanding the carbohydrate dynamics of sprouting Cirsium arvense (L.) Scop. and Sonchus arvensis L. ramets can assist in optimizing perennial weed management. However, detailed knowledge about general reserve dynamics, minimum values in reserves (compensation point) and different reserve determination methods remains sparse. We present novel insights into reserve dynamics, which are especially lacking for S. arvensis. We uniquely compare root weight changes as a proxy for carbohydrates with direct carbohydrate concentration measurements using high-performance liquid chromatography (HPLC). In a greenhouse study, ramets of two sizes (20 and 10 cm) were planted in pots. Subsequent creeping roots of sprouted plants were destructively harvested and analyzed for carbohydrates 12 times between planting and flowering. Efficiency in storing carbohydrates and the replenishing rate of root weight and carbohydrates was much higher in S. arvensis than in C. arvense. Thus, our study urges to evaluate perennial weed species individually when investigating root reserves. Determining root reserves by either using root weight changes as a proxy for carbohydrates or directly measuring carbohydrate concentrations by HPLC differed in the minimum values of reserves referred to as compensation points. For both species, these minimum values occurred earlier based on root weight than based on carbohydrate concentrations. Cutting ramets into 20 or 10 cm sizes did not significantly affect carbohydrate concentration or root weight changes for both species. We conclude that any practical applications targeting perennial weeds by fragmenting roots into small ramets through belowground mechanical control must be evaluated for trade-offs in soil structure, soil erosion, and energy consumption.

On May 1, 2024, a small embankment collapse occurred in the early hours of the morning on the Meida Highway in Meizhou City, Guangdong Province, resulting in 48 fatalities. The small-scale collapse caused massive casualties and garnered widespread attention. In detail, there is a significant lack of precipitation at the time of the 51 Meida collapse disaster, lagging 10 h behind the peak precipitation. The collapse occurs on a mountainous slope, with a hollow catchment area located above the embankment. Multiple potential streams converge in the area, contributing to the water flow towards the slope. Within the western zone of the Lianhua Mountain fault, the collapse area is crossed by fault lines at approximately 800 m on the upper side and 650 m on the lower side. Bedrock fractures formed by faults act as water conduits. The combination of catchment topography and potential faults enriches the water around the embankment slope, contributing to its instability. The disaster site is situated within granite formations. The refilling soil, composed of weathered granite, exhibits poor hydro-mechanical properties, making the slope particularly susceptible to failure due to the effects of multi-source water infiltration. A key insight from this research is that potentially unstable embankment slopes should be identified by considering the interaction between multi-source water and soil/rock. Greater emphasis should be placed on factors such as fault development and hollow topography above the slope, which influence the effects of multi-source water. These factors should be quantified in future studies to improve the assessment of unstable highway slopes in mountainous regions. The findings and strategies outlined in this study can serve as a valuable reference for assessing both embankment and natural slopes in mountainous areas.

The impact of four distinct calcium sources on the microbial solidification of sand in the Kashi Desert, Xinjiang, was investigated. A wind tunnel test over a 60-day period revealed the cracking behavior of four different complex calcium nutrient solutions. By comparing the bearing capacity and the results from dry-wet cycling and freeze-thaw cycle tests, it was concluded that the sample treated with calcium gluconate exhibited superior sand fixation performance, whereas the sample treated with calcium acetate showed weaker sand fixation effects. The microstructure of the treated sand samples was analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Elemental analysis was conducted via energy dispersive spectroscopy (EDS), and functional groups were identified through Fourier transform infrared spectroscopy (FTIR). These experimental findings hold significant implications for soil remediation, pollutant removal in soil, enhancement of soil fertility, and desert soil stabilization.