Wet Conditions Research Articles

Seasonal drought drives sugarcane borer outbreaks.

Sugarcane borers (SCB) pose a major threat to sugarcane production. Effective pest management requires detailed knowledge of SCB phenology and population dynamics in responses to environmental changes. This study tested the hypothesis that drought drives SCB outbreaks and identified season-specific effects by investigating large-scale field data of these pests in 4 key sugarcane-growing provinces in south subtropical and tropical China (Guangxi, Guangdong, Yunnan, and Hainan) from 1987 to 2018. The standardized precipitation evapotranspiration index was used as a drought indicator at various time scales. We found that drought during a specific month can result in significant changes in the annual SCB outbreak status, such as November in Guangxi, June in Yunnan, and September in Hainan. By summarizing seasonal effects of drought across study locations, we found a general pattern that SCB outbreaks increased with drier conditions in summer, whereas they were promoted by wetter conditions in fall. This research provides crucial knowledge for predicting SCB outbreaks under seasonal and climate changes. This information is also highly critical for increasing the efficiency and accuracy of integrated pest management strategies.

Influence of Different Cements on Bonding Efficiency Between Implant Abutment and Standard Restoration.

This study aimed to investigate the efficiency of different cements for luting implant restorations. Standard restorations were bonded with different cements, including a zincoxide-based temporary cement (ZOE), a resin-modified glass ionomer cement (GIC) and a resin-based, eugenol-free cement (RBEFC). The restorations were stored under moist conditions and were subsequently subjected to thermal cycling and mechanical loading (TCML). Retention forces were determined with an axial tensile test and removabilty of the restorations was analyzed with a pneumatic crown remover. GIC provided significantly higher retention forces than RBEFC, which provided significantly higher values than ZOE. After storage, retention forces were significantly higher than after TCML. With regard to removability, no significant differences were identified between ZOE and RBEFC, but a significantly higher number of applications was required to remove restorations luted with RBEFC. All cements provided sufficient retention forces, yet removal of restoration might be more demanding if luted with RBEFC.

Moisture-induced mechanical property changes in natural hybrid composites with mwcnt fillers

ABSTRACT This study investigates the moisture absorption behaviour and its effects on the mechanical properties of polyester composites reinforced with jute and hemp fibres. The differences in moisture absorption between distilled water and saltwater are examined. Tensile and flexural tests are conducted on pure jute fibre-reinforced polyester composite, pure hemp fibre-reinforced polyester composite, and jute (J-P) and hemp (H-P) fibre-reinforced polyester composite. Changes in mechanical properties due to varying moisture conditions are analysed. Furthermore, the impact of a synthetic nano filler, multiwall carbon nanotubes (MWCNTs), on these composites is assessed. The study reveals that MWCNTs enhance mechanical properties, particularly in moist conditions. Fracture behaviour analysis aids in understanding the interaction between natural fibres, the matrix, and nano-reinforcement. At maximum natural fibre weight fractions (40%), moisture absorption reaches 8.17% for the J-P composite in distilled water and 9.61% in saltwater, while the H-P composite shows maximum absorptions of 6.61% and 8.27%, respectively. The hybrid composite records 4.18% and 7.17% under similar conditions. Compared to the plain jute fibre-reinforced composite, the addition of multiwall carbon tubes into the polymer matrix significantly reduces the moisture absorption capacity of the jute composite to 34.89% and 31.30% for distilled water and saltwater, respectively.

Micro-Incubator Protocol for Testing a CO2 Sensor for Early Warning of Spontaneous Combustion

A protocol for detecting the potential occurrence of spontaneous combustion (SC) in stored cottonseeds and peanuts using a micro-incubator is described. The protocol indicates how to quantify CO2 production rates and final CO2 levels in wet versus dry cottonseed and peanut samples, which can provide crucial data for the early detection of SC risk in storage facilities. The experimental design utilizes a micro-incubator to simulate conditions found in large bulk crop storage. Parameters monitored include CO2 concentration, temperature, and relative humidity. The protocol includes preparation methods, experimental procedures for both control (dry) and wet seed tests, and test termination criteria that allow for safe experimentation of likely pathogenic fungi. The protocol has three replicates for wet and dry conditions. The protocol is intended to facilitate future experimental studies and ultimately contribute to the development of a consistently reliable early warning fire detection system for SC in cottonseed and peanut warehouse facilities. A consistently reliable fire detection system would address a critical need in the cotton and peanut industry for improved fire risk management and insurability of storage facilities.

The friction modifier performance in twin-disc tests using discs of the same microstructure and hardness

Friction management in the wheel-rail interface has received great attention from railway engineering in recent years, mainly due to the possibility of reducing wheel and rail wear. The addition of greases, lubricants and friction modifiers on the track has increased in the main railroads of the world. However, studies demonstrating the effect of applying friction modifiers are mainly carried out by manufacturers. To evaluate the action of the friction modifier, laboratory tests are less expensive tools and can give an indication of the benefit of the application. Thus, in this work, dry and wet twin-disc tests were carried out using discs with the same microstructure and hardness, evaluating only the action of the friction modifier. It was noted that the retentivity of the friction modifier had increased with the distance covered in the test. These results would contribute to increase the distance between applicators on the railway track and promoting a lower volume of product per distance traveled. The addition of a friction modifier also reduced the traction coefficient throughout the test, which contributed to lower wear of the disc. The friction modifier induced Rolling Contact Fatigue - RCF cracks with greater depth and length due to hydro pressurization action. However, the addition was still beneficial because the wet condition keeping the friction at smaller values, the crack propagation takes longer to occur.

Role of the Europe–China Pattern Teleconnection in the Interdecadal Autumn Dry–Wet Fluctuations in Central China

Based on statistical analyses of long-term reanalysis data, we have investigated the interdecadal variations of autumn precipitation in central China (APC-d) and the associated atmospheric teleconnection. It reveals that the increased autumn rainfall in central China during the last decade is a portion of the APC-d, which exhibits a high correlation coefficient of 0.7 with the interdecadal variations of the Europe–China pattern (EC-d pattern) teleconnection. The EC-d pattern teleconnection presents in a “+-+” structure over Eurasia, putting central China into the periphery of a quasi-barotropic anticyclonic high-pressure anomaly. Driven by positive vorticity advection and the inflow of warmer and moist air from the south, central China experiences enhanced ascending motion and abundant water vapor supply, resulting in increased rainfall. Further analysis suggests that the EC-d pattern originates from the exit of the North Atlantic jet and propagates eastward. It is captured by the Asian westerly jet stream and proceeds towards East Asia through the wave–mean flow interaction. The wave train acquires effective potential energy from the mean flow by the baroclinic energy conversion and simultaneously obtains kinetic energy from the basic westerly jet zones across the North Atlantic and the East Asian coasts. The interdecadal variation of the mid-latitude North Atlantic sea surface temperature (MAT-d) exhibits a significant negative relationship with EC-d, serving as a modulating factor for the EC-d pattern teleconnection. Experiments with CMIP6 models predict that the interdecadal variations in APC-d, EC-d, and MAT-d will maintain stable high correlations for the rest of the 21st century. These findings may contribute to forecasting the interdecadal autumn dry–wet conditions in central China.

Thermal behavior of pervious concrete in wet conditions

Thermal behavior of pervious concrete in wet conditions

Low-Cost Sensors for the Measurement of Soil Water Content for Rainfall-Induced Shallow Landslide Early Warning Systems

Monitoring soil water content (SWC) can improve the effectiveness of early warning systems (EWSs) designed to mitigate rainfall-induced shallow landslide risk. In extensive areas, like along linear infrastructures, the adoption of cost-effective sensors is critical for the EWS implementation. The present study aims to evaluate the reliability of different low-cost SWC sensors (frequency domain reflectometry and capacitance-based) in capturing soil moisture conditions critical for EWS, without performing soil-specific calibration. The reliability of the low-cost sensors is assessed through a comparative analysis of their measurements against those from high-cost and well-established sensors (time domain reflectometry) over a two-year period in a shallow landslide-prone area of Oltrepò Pavese, Italy. Although no landslides are observed during the monitoring period, meteorological conditions are reconstructed and statistical analysis of sensor’s responses to different rainfall events is conducted. Results indicate that, despite differences in absolute readings, low-cost sensors effectively capture relative SWC variations and demonstrate sensitivity to rainfall events across both cold and warm periods. The presented low-cost sensors can serve as reliable indicators of soil infiltration and saturation levels, highlighting their potential for real-time monitoring within extensive networks for EWS.

Pros and Cons of Different Irrigation Scheduling Approaches: A Review

Scheduling irrigation involves making a decision of how much water to apply and when. Three factors enter into the decision: water needs of the plants, water availability, and storing capacity of the soil around the roots. When to irrigate should be greatly influenced by water needs of the plants. Irrigation scheduling (IS) aims to give plants the right amount of water at the right times in order to promote plant growth and achieve high yield and/or quality. The four most popular ways of operating irrigation scheduling includes: evapotranspiration and water balance (ET-WB), soil moisture status, plant water status, and models based irrigation scheduling. When the four types of irrigation scheduling systems are thoroughly examined, it becomes clear that they are all centered on soil moisture, which serves as a link or bridge between crop water needed for growth and irrigation management). A few studies have been accomplished on pros and cons of different irrigation scheduling approaches. The purpose of this review was to provide some information on pros and cons of four selected irrigation scheduling methods, viz: evapotranspiration and water balance (ET-WB), soil moisture status, plant water status, and models based irrigation scheduling. When the four types of irrigation scheduling systems are thoroughly examined, it becomes clear that they are all centered on soil moisture, which serves as a link or bridge between crop water needed for growth and irrigation management. Plant-based techniques can need professional oversight since farmers may find it difficult to understand the tracked data, which reduces the dependability of irrigation. When built software or a procedure is based on a well-calibrated model, model-based methods are simpler for users. When compared to the soil moisture sample irrigation scheduling approach, the evapotranspiration losses irrigation scheduling method uses less irrigation water regardless of the minimal yield difference.

Step‐wise non‐solvent induced phase separation of polyacrylonitrile/thermoplastic polyurethane self‐supportive filtration membranes

AbstractThis study investigated the fabrication of polyacrylonitrile (PAN) membranes using non‐solvent induced phase separation methods, with the addition of thermoplastic polyurethane (TPU) as an additive. The incorporation of TPU and the utilization of stepwise induced phase separation techniques resulted in notable improvements in membrane structure and water filtration performance. Scanning electron microscopy revealed that membranes with TPU exhibited a denser pore network and finer primary channels, leading to enhanced water flux and protein rejection rates. Mechanical testing indicated that TPU addition improved the membrane's mechanical properties, particularly its elongation at break and tensile strength, especially under wet conditions. Additionally, optimization of the coagulation bath involved methanol spraying followed by water immersion, resulting in membranes with further enhanced flux and rejection properties. Compared with neat PAN membranes, the membranes with TPU exhibited increased water flux from 405 to 539 L/m2 h, as well as improved elongation at break and tensile strength in both dry and wet conditions. Furthermore, the combination of stepwise induced phase separation significantly enhanced the water flux from 342.7 to 483.0 L/m2 h, while also improving the retention rate of ovalbumin from 25.7% to 31.5%.

Modeling the Effect of Milk Vetch–Rice Rotation on N Runoff Loss in the Middle and Lower Reaches of the Yangtze River

The winter planting of green manure (GM) is widely used in South China to reduce chemical nitrogen (N) fertilizer use, improve soil fertility, and maintain rice yields, but its effect on N runoff loss in paddy fields remains unclear. This study combines multi-site field experiments with a process model (WHCNS-Rice) to assess how GM with reduced N fertilizer impacts N runoff loss and its forms in the Yangtze River’s middle and lower reaches, considering different rainfall years. The network field experiments included four treatments: conventional fertilization (FR), conventional fertilization plus straw return (FRS), GM with a 40% N reduction (MR), and GM-straw combined return with a 40% N reduction (MRS). Monitoring the results showed that compared to the winter fallow treatment, the GM treatments reduced the peak and average total N (TN) concentrations by 11.1–57.9% (average 26.9%) and 17.1–27.3% (average 22.3%), respectively. The TN runoff loss under the GM treatment decreased by 3.50–10.61 kg N ha−1 (22.5–42.1%). GM primarily reduced the runoff loss of dissolved inorganic N (DIN), with reductions at different sites ranging from 0.22 to 9.66 kg N ha−1 (8.4–43.4%), indicating GM effectively decreases N runoff by reducing DIN. Model simulations of ponding water depth, runoff, TN concentration in surface water, and TN loss in paddy fields produced the consistency indices and simulation efficiencies of 0.738–0.985, 0.737–0.986, 0.912–0.986, and 0.674–0.972, respectively, indicating that the model can be used to evaluate water consumption and N runoff loss in the GM-paddy system. The simulations showed that GM with a 40% N fertilizer significantly reduced N runoff loss under all rainfall conditions, with the greatest reductions in wet years. Under wet, normal, and dry conditions, the GM treatments significantly reduced average TN loss by 0.37–5.53 kg N ha−1 (12.77–29.17%), 0.21–5.32 kg N ha−1 (9.95–24.51%), and 0.02–3.2 kg N ha−1 (1.78–23.19%), respectively, compared to the winter fallow treatment. These results indicate that the combination of GM and a 40% reduction in N fertilizer can significantly reduce N runoff loss from paddy fields, demonstrating good effectiveness under various rainfall conditions, making it a green production model worth promoting.

Effect of moisture on mechanical and physical properties of coals: a uniaxial compression study

The estimation of mechanical and physical properties of coal reservoirs is important for the successful exploration and development of coalbed methane (CBM). Unlike conventional sandstone reservoirs, coal reservoirs exhibit greater sensitivity to stress, resulting in distinct mechanical and physical behaviors. In this study, uniaxial compression tests were performed on both low-rank and high-rank coal samples under different moisture conditions to reveal the mechanical and physical property changes with stress. The results indicate that during axial stress loading (up to 2.8 MPa), axial strain initially increases rapidly and subsequently at a slower rate, with an axial strain of 0.13–0.25% observed at the maximum axial stress. The instantaneous Young’s modulus increases linearly before stabilizing, ranging from 618.01 to 4861.10 MPa, while the Poisson’s ratio remains relatively constant or increases linearly, ranging from 0.002 to 0.165. This results in a negative exponential decrease in both porosity and permeability, with maximum reductions of 1.77–4.21% and 5.38–12.25%, respectively. The mechanical properties of coal are influenced by both the cementation effect of water at low water saturation and the softening effect at high water saturation, which results in axial strain decreases and then increases as the water saturation increases. Concurrently, the elastic modulus initially increases and then decreases, while the Poisson’s ratio exhibits a less pronounced change or tends to increase. Consequently, there is a trend in which porosity and permeability first increase and then decrease. In addition, during stress unloading, the influence of water in coal induces a notable strain hysteresis phenomenon in water-containing coal samples, and this phenomenon is more obvious in the low-rank coals.

Evaluation of thermal effects of surgical energy devices: ex vivo study

This study evaluated the direct and indirect thermal effects of various surgical energy devices using an ex-vivo model. Two types of three devices were evaluated: ENSEAL™ X1 Curved Jaw Tissue Sealer (X1) and ENSEAL™ G2 Curved Tissue Sealer (G2) as vessel sealing systems (VSSs), and HARMONIC® HD1000i Shears (HA) as an ultrasonic activating device (USAD). Each device was activated once under DRY or WET conditions. The tissue’s maximum temperature (MT), steam MT surrounding the activation site, and steam spread area (SSA) were measured. Under WET conditions, the median MT of a porcine common carotid artery at 1 mm from the activation site by X1, G2, and HA were 84.4, 83.3, and 50.5 °C, respectively. The direct thermal effect of HA was the lowest among the three devices. VSSs showed higher tissue MT under WET conditions compared with DRY conditions. Conversely, USAD showed the opposite trend. G2 demonstrated a significantly higher MT than X1 and HA (P < 0.05). A significant decrease in SSA was observed with decreasing grasping range. In conclusion, VSSs generated higher temperatures than USAD, especially under WET conditions. Surgeons should consider minimizing thermal effects by creating DRY conditions or performing gradual incisions when using VSS devices.

Moving beyond species: fungal function in house dust provides novel targets for potential indicators of mold growth in homes

BackgroundIncreased risk of asthma and other respiratory diseases is associated with exposures to microbial communities growing in damp and moldy indoor environments. The exact causal mechanisms remain unknown, and occupant health effects have not been consistently associated with any species-based mold measurement methods. We need new quantitative methods to identify homes with potentially harmful fungal growth that are not dependent upon species. The goal of this study was to identify genes consistently associated with fungal growth and associated function under damp conditions for use as potential indicators of mold in homes regardless of fungal species present. A de novo metatranscriptomic analysis was performed using house dust from across the US, incubated at 50%, 85%, or 100% equilibrium relative humidity (ERH) for 1 week.ResultsGene expression was a function of moisture (adonis2 p < 0.001), with fungal metabolic activity increasing with an increase in moisture condition (Kruskal–Wallis p = 0.003). Genes associated with fungal growth such as sporulation (n = 264), hyphal growth (n = 62), and secondary metabolism (n = 124) were significantly upregulated at elevated ERH conditions when compared to the low 50% ERH (FDR-adjusted p ≤ 0.001, log2FC ≥ 2), indicating that fungal function is influenced by damp conditions. A total of 67 genes were identified as consistently associated with the elevated 85% or 100% ERH conditions and included fungal developmental regulators and secondary metabolite genes such as brlA (log2FC = 7.39, upregulated at 100% compared to 85%) and stcC (log2FC = 8.78, upregulated at 85% compared to 50%).ConclusionsOur results demonstrate that moisture conditions more strongly influence gene expression of indoor fungal communities compared to species presence. Identifying genes indicative of microbial growth under damp conditions will help develop robust monitoring techniques for indoor microbial exposures and improve understanding of how dampness and mold are linked to disease.-X5AkW-U2mftBzktcaxDSrVideo

Pressure Injuries and the Waterlow Subscales in the Intensive Care Unit: A Multicentre Study.

Pressure injuries (PIs) impose a significant burden on patients in the intensive care unit (ICU) and the healthcare system. Assessing the risk of developing PIs is crucial for prevention. However, it is unclear whether all subscales of the Waterlow scale can be used to assess PIs risk in ICU. To assess whether all subscales of the Waterlow scale can predict PIs risk in ICU. Multicentre prospective study. A total of 18,503 patients from ICUs in 40 tertiary-level hospitals in Gansu province of China were enrolled from April 2021 to August 2023. The incidence and characteristics of PIs were recorded. Univariate Cox regression analyses were performed for each subscale as a predictor of PIs development, followed by multivariate Cox regression with covariates for each subscale separately. Out of 17,720 patients included, the incidence of PIs was 1.1%. Multivariate analysis revealed skin type (HR: 1.468, 95% CI: 1.229, 1.758), sex (HR: 0.655, 95% CI: 0.472, 0.908), advanced age (HR: 1.263, 95% CI: 1.106, 1.442), continence (HR: 1.245, 95% CI: 1.052, 1.473), tissue malnutrition (HR: 1.070, 95% CI: 1.007, 1.136) and neurological deficit (HR: 1.153, 95% CI: 1.062, 1.251) were independently predictive of PIs development for all participants. Skin type (HR: 2.326, 95% CI: 1.153, 3.010) (HR: 2.217, 95% CI: 1.804, 2.573) independently predicted PIs occurrence for high-risk and very high-risk group, respectively, while sex (HR: 0.634, 95% CI: 0.431, 0.931) and age (HR: 1.269, 95% CI: 1.083, 1.487) predicted PIs development for very high-risk group. This study found that not all subscales of the Waterlow scale are associated with the PIs development in patients in ICU, highlighting the importance of the skin type subscale in predicting PI risk across all patient groups. Nurses need to focus on patient's skin and related (moisture, pain and pressure) conditions and take measures to promote skin health and avoid the occurrence of PI. None.

Fabrication of Long-Lasting Superhydrophilic Anti-Fogging Film Via Rapid and Simple UV Process.

Surface fogging is a common phenomenon that can result in restricted visibility, reduced light absorption, and image distortion. Although both hydrophobic and hydrophilic surfaces are effective in preventing this phenomenon, typical coatings in both have limitations, including low durability and the need for frequent reapplication. To address these issues, a highly durable anti-fogging film that lasts over five weeks, even under high moisture conditions, while maintaining a promising degree of transparency (> 60%) is developed. A novel statistical random copolymer containing superhydrophilic and photo-crosslinkable segments that can be simultaneously crosslinked and chemically bonded to various substrates via a simple ultraviolet (UV) irradiation process is synthesized. Notably, the chemical bonding between the anti-fogging coating and substrate improves not only the durability but also the resistance to external forces and environmental changes. Furthermore, this film is versatile and applicable to diverse substrates, such as car windshields, polymer films, and aluminum foil. The innovative strategy offers a simple, rapid process and durable anti-fogging performance with broad applications in the automotive industry, optical devices, and building materials.

Modeling soil acidity (pH) dynamics under extreme agroclimatic conditions in Horro Guduru Wallaga Zone, northwestern Ethiopia.

Soil plays a critical role in nutrient availability, microbial activity, and fertility in agriculture. However, the effects of agroclimatic conditions on soil pH are not well understood, particularly in the Horro Guduru Zone of Ethiopia. This study aimed to investigate the soil pH under extremely wet and dry conditions across 3 shared socioeconomic pathway (SSP) scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Baseline agroclimatic data (1981-2010) and future projections (2041-2070) were obtained from the European Commission Climate Change Services. Soil pH data at a 250m resolution were extracted from the FAO-UNESCO global soil map. Missing values, multicollinearity, and outliers were addressed before modeling. Predictive models, including neural networks, generalized regression, and bootstrap forests, were validated, with the generalized regression model showing the best performance. The results indicate that soil pH decreases under consecutive dry‒wet conditions and increases with increasing maximum day temperatures across all scenarios. Soil pH is significantly influenced by the number of consecutive dry days, consecutive wet days, and maximum day temperature. The SSP1-2.6 and SSP2-4.5 scenarios resulted in improved pH levels, whereas SSP5-8.5 led to a decrease in soil pH, averaging 5.79 and decreasing to 5.54. These findings suggest that under SSP5-8.5, soil health and farming productivity may be compromised. This study emphasizes the need to adjust soil management practices based on prevailing climatic conditions to ensure soil health and agricultural sustainability.

Spatio-temporal changes in atmospheric aridity over the arid region of Central Asia during 1979–2019

The arid region of Central Asia (CA) is the largest non-zonal arid region in the world. It has experienced significant changes in climate and hydrological cycle systems owing to global warming, which has posed serious impacts on the water resources and ecological environment in this region. Although the atmospheric water vapor pressure deficit (VPD) can directly reflect the atmospheric moisture condition, studies on the change of atmospheric moisture deficit in CA are scarce. Thus, we investigated the changes in VPD in the arid region of CA from the perspective of atmospheric aridity based on the CRU TS4.04 and ERA5 data. Our results showed that the VPD in more than 95 % of grids in the arid region had a significantly increasing trend during 1979–2019. Seasonally, VPD trends were increasing in spring, summer, and autumn but decreasing in winter. The changes in saturated water vapor pressure and actual water vapor pressure determined the VPD changes. The saturated water vapor pressure showed a clearly upward trend, whereas the actual water vapor pressure did not increase at the same rate, resulting in the increase of VPD. The first four leading modes revealed by empirical orthogonal function (EOF) analysis represented the patterns by explaining 81.4 % of the total variance. The positive phase of EOF1 was characterized by a monopole pattern, and this mode continued to increase. Contrastingly, EOF2 (and EOF3) showed dipole patterns over east–west CA (and north–south CA), with a mainly interannual variability. Due to the combined effect of increasing temperatures and decreasing relative humidity, the VPD has been intensifying since the mid-to-late 1990 s in CA, and the atmosphere has become significantly drier. These research results can deepen the scientific understanding of global warming impacts on atmospheric moisture and provides a reference for revealing the VPD changes and their impacts on the climate system and ecosystem in arid regions. Our results highlight that the impacts of VPD change should be adequately considered in environmental management and policy-making processes in Central Asia.

Characterization and prediction of hydraulic properties of traffic-compacted forest soils based on soil information and traffic treatments

Key messageThe hydraulic properties of compacted and rutted soils were evaluated through in-situ infiltration experiments and predicted based on soil texture class and traffic treatments. A significant decrease in saturated soil water content and soil hydraulic conductivity at saturation was observed. The resulting soil hydraulic parameters, when integrated into a soil water transfer model, effectively simulated water dynamics in these impacted forest soils, providing a crucial first step toward developing decision support tools for real-time trafficability. This approach can assist forest managers in minimizing the extent of soil compaction.ContextTo overcome trafficability issues of forest soils induced by heavy logging machinery, planning support tools are needed to determine suitable soil moisture conditions for traffic.AimsThis study aimed to identify the soil properties that differ significantly between undisturbed and compacted soils and to provide several estimation tools to predict the hydraulic properties of compacted soils beneath the skid trails.MethodsFour hundred seventeen water infiltration tests were conducted on 19 forest sites, mostly in North-eastern France, and analysed with the BEST method to estimate the hydraulic properties of the skid trails and undisturbed soils. The hydraulic properties of the skid trails were predicted thanks to linear mixed effect models using a bulk treatment effect, a site effect, or a skid trail degradation score. The predicted hydraulic properties were tested using a water flow model to assess their relevance regarding the prediction of water dynamics in skid trails.ResultsThe compaction effect was only significant for the logarithm of the hydraulic conductivity at saturation (log10(Ksat)) and the soil water content at saturation (θsat). For the skid trails, θsat was reduced by - 0.02 and − 0.11 m3m−3 in the 0 − 10 cm and 15 − 25 cm layers respectively, compared to undisturbed topsoil (0 − 10 cm). log10(Ksat) was reduced by − 0.38 and − 0.85 for skid trails in the 0 − 10 and 15 − 25 cm soil layers respectively, compared to undisturbed topsoil. The use of a pedotransfer function, in replacement of water infiltration tests, and their combination with the same correction coefficients proved to efficiently simulate the difference in water dynamics between skid trails and undisturbed forest soils.ConclusionEstimation of soil hydraulic properties based on in situ water infiltration experiments proved efficient to simulate water dynamics in compacted and rutted forest soils. Yet, further studies are needed to identify the most adapted pedotransfer function to forest soils and to test the generalisation of our findings in different conditions, especially deeply rutted soils (rut depths > 12 cm).

Study on the Development Rule of Mudstone Cracks in Open-Pit Mine Dumps Improved with Xanthan Gum

The stability of open-pit mine slopes is crucial for safety, especially for spoil dump slopes, which are prone to cracks leading to landslides. This study investigates the use of xanthan gum (XG) to enhance the stability of mudstone in spoil dumps. Various concentrations of xanthan gum were mixed with mudstone and subjected to dry–wet cycle tests to assess the impact on crack development. Pore and crack analysis system (PCAS) was utilized for image recognition and crack analysis, comparing the efficiency of crack rate and length modification. The study found that xanthan gum addition significantly improved mudstone’s resistance to crack development post-drying shrinkage. A 2% xanthan gum content reduced the mudstone crack rate by 45% on average, while 1.5% xanthan gum reduced crack length by 46.2% and crack width by 26.3%. Xanthan gum also influenced the fractal dimension and water retention of mudstone cracks. The optimal xanthan gum content for mudstone modification was identified as between 1.5% and 2%. Scanning electron microscopy imaging and X-ray diffraction tests supported the findings, indicating that xanthan gum modifies mudstone by encapsulation and penetration in wet conditions and matrix concentration and connection in dry conditions. These results are expected to aid in the development of crack prevention methods and engineering applications for open-pit mine spoil dump slopes.