Severe Erosion Research Articles

Soil Conservation Services and Its Enlightenment for Improving Ecosystems for Rocky Desertification Management: A Literature Review and Bibliometric Analysis

Soil conservation service (SC), as one of the most crucial ecosystem services (ES), plays a vital role in promoting the restoration of ecosystem structure. Severe soil erosion in karst areas has resulted in the ongoing degradation of soil conservation services. Understanding the current and evolution of research in this field is essential for establishing a theoretical foundation for the future management of rocky desertification in karst areas. Based on the Web of Science (WOS) and China Knowledge Network (CNKI) databases, 224 articles on SC were collected. This paper summarizes the research progress, results, and development trends from various aspects through systematic review and qualitative analysis of the literature. The findings are visually presented using spatial visualization and analysis tools such as SATI and Gephi. Key scientific issues and future development trends of existing SC are summarized with a view to improving SC in rocky desertification areas. It is of great significance to further improve the layout of ecological engineering construction and rocky desertification management in karst regions.

Exploring the relationship between drought-flood abrupt alternation and soil erosion over Guangdong, China through a convection-permitting model

Climate change has caused a more heterogeneous distribution of extreme precipitation, leading to the deterioration of drought-flood abrupt alternation (DFAA) events and soil erosion. The security and sustainable utilization of water and soil resources are severely threatened. Previous studies have focused separately on these two aspects, failing to comprehensively consider their interrelationship. Furthermore, these studies often rely on climate models with convection parameterization, resulting in substantial uncertainties. We use a 4 km convective permitting model (CPM) to generate reliable outputs for extreme precipitation. By incorporating the long-cycle drought-flood abrupt transition index and the Revised Universal Soil Loss Equation model, we analyze the changes in DFAA events and soil erosion, as well as their interconnectedness. The results show that the CPM outperforms coarse-resolution climate models in reproducing erosive rainfall and simulating the heterogeneous distribution of rainfall by capturing convection processes effectively. Projections indicate an escalation in the occurrence of DFAA events and soil erosion due to the more uneven distribution of precipitation. Specifically, the frequency of flood-to-drought (FTD) events within DFAA is projected to rise from 3.8 to 4.7 per decade. Soil loss is projected to increase 61 t·hm−2·a−1, with 73% of the area experiencing more severe soil erosion intensity. A positive correlation between FTD events and soil erosion is found throughout most of Guangdong. This correlation will be further amplified with an increase in the frequency of FTD events. Consequently, existing soil conservation measures are rendered inadequate, presenting substantial challenges for climate change adaptation and ecological protection in the region.

The influence of dietary and lifestyle factors on GERD-related dental erosion: A literature review

Background: Gastroesophageal reflux disease (GERD) is a chronic gastrointestinal disorder commonly associated with dental erosion. GERD-related dental erosion is influenced by various factors, including dietary habits and lifestyle choices. Purpose: This article aims to review the influence of dietary and lifestyle factors on GERD-related dental erosion based on a literature review. Methods: This study employed a literature review methodology, analyzing articles published between 2019 and 2024. Data sources were obtained from databases such as PubMed, Google Scholar, ScienceDirect, and Elsevier. A total of 8 articles met the inclusion criteria and were analyzed further. Results: Studies indicate that the consumption of acidic foods and beverages, such as citrus fruits and carbonated drinks, exacerbates dental erosion in GERD patients. Lifestyle factors, such as late-night eating and caffeine consumption, were also found to increase the risk of dental erosion. Conversely, the consumption of milk was associated with a reduction in the severity of erosion. GERD also affects the salivary profile, including lowering the pH and buffering capacity of saliva, thereby increasing the risk of enamel demineralization. Conclusion: Dietary and lifestyle factors play a significant role in increasing the risk of GERD-related dental erosion. A holistic management approach, including dietary modifications, lifestyle changes, and regular dental health monitoring, is necessary to reduce the impact of GERD on dental health.

Joint Probability Analysis of the Rich‐Poor Runoff and Sediment Discharge in Karst Watersheds

AbstractAs one of the largest contiguous karst landscapes in the world, southwest China has experienced severe soil erosion because of its frequent climate extremes, special hydrogeology, shallow and discontinuous soil, steep topography, and inappropriate land use. Furthermore, the construction of dams in recent decades has rendered the relationship between runoff and sediment discharge increasingly complex. However, the joint probability distributions and joint return periods of runoff‐sediment discharge relationship are still not clear. The objective of this study was to investigate the synchronous‐asynchronous probabilities and return periods of rich‐poor combinations of annual runoff and sediment discharge using a bivariate copula function to assess the risk of soil erosion in four selected karst watersheds in southwest China. Results showed that sediment discharge has declined significantly in all watersheds except Liujiang, and annual runoff and sediment discharge were significantly positively correlated in all watersheds. The optimal marginal distribution and the best copula function of annual runoff and sediment discharge are not identical for each watershed. The synchronous and asynchronous probabilities of annual runoff and sediment discharge are close to 1:1 in the Wujiang watershed. The asynchronous probability is much higher for the combination of less runoff with more sediment discharge (r < s) than for the combination of more runoff with less sediment discharge (r > s) in Nanpanjiang. Therefore, the risk of soil erosion may be higher in the Wujiang and Nanpanjiang watersheds. The joint return periods of runoff‐sediment discharge were concentrated in less than 5 years during the historical period. These return periods can provide data references for designing the scale of water resources projects and help in better soil erosion control in the future. This study could be a technical reference for identifying the non‐stationarity of the multivariate relationship between runoff and sediment discharge in karst regions.

Immunopathological Changes of Streptococcus pneumoniae Causing Respiratory Infection in Lambs

Streptococcus pneumoniae are common bacterial pathogens that can cause a range of diseases in humans and animals. This study attempts to clarify the course and consequences of pneumonia caused by this bacterial infection. A total of 6 male un-weaned lambs aged between 1 to 2 months and weighing 5 to 7 kg were subjected to S. pneumoniae strain ATCC 6303 serotype 3 at ‎2×106 ‎CFU/mL by inhalation to induce pneumonia. Pneumonic clinical signs were ‎monitored daily throughout the study period. The blood samples were collected from all animal groups at day zero before pneumoniae induction and 3, 6, and 14 days post infection for total and differential white blood cell count ‎(WBCs) and tumor necrosis factor-alpha (TNF-α) assessments. Additionally, on days 6 and 14 post-exposure, trachea and lung tissue samples were harvested for macroscopic and microscopic pathological changes evaluation. The results showed that there was a significant increase (P<0.001) in total WBC counts from day 3 post-exposure and maintaining elevated levels on days 6 and 14 compared to day zero. Differential WBC counts showed an early, significant rise in neutrophils, with sustained ‎elevation in lymphocytes and monocytes. TNF-α‎ levels significantly elevated on day 3‎ and gradually declined by day 14‎ post-exposure (P<0.001). On day 6 post-exposure, the gross pathological changes in the lung showed pulmonary edema, and emphysema, with mild to moderate lung congestion and emphysematous changes observed on day 14 post-exposure. Histopathologically, severe erosion and necrosis in the trachea and bronchus epithelium, along with inflammation in adjacent mucosa and submucosa, accompanied by focal inflammatory infiltration and emphysema in the lung by day 6 post-exposure, were observed. By day 14, these changes progressed to marked epithelial vacuolation and necrosis in the trachea, with lung sections revealing perivascular cuffing, peri bronchiolitis, mild bronchiectasis, atelectasis, and alveolar collapse. This study is attempt for a better understanding of S. pneumoniae infection in lamb and contributing to the development of preventive and management strategies in Iraq‎‎‎.

Large-scale ecological infrastructures enhance the productivity of agro-socio-ecological systems by reducing soil erosion in the Loess Plateau.

Agro-socio-ecological systems are a crucial link connecting urbanization, agricultural development and environmental evolution. However, there is no effective research on realizing regional collaborative development and environmental governance of the agricultural social-system collaborative governance model, especially spatial differentiation governance. In this study, the region with the most severe soil erosion in the world was selected as the research area. We used socio-economic statistical data and remote sensing data, combined with the Revised Universal Soil Loss Equation, to provide analytical evidence in different sub-regions. Results showed that the soil erosion rate of the Loess Plateau has dropped significantly during the past three decades, with an average decreasing rate of 0.46tha-1 yr-2 or 2.33%. Large-scale investments in ecological infrastructure (e.g., check dams) increase agro-socio-ecological productivity by reducing soil erosion. The productivity of social-ecological systems increased significantly, especially after 2000, with the grain production capacity and gross primary productivity rising by 84.28% and 18.06% from 1990 to 2017. The decrease in grain yield caused by the ecological return of upland cropland and the occupation of high-quality cropland will be raised to a better level. Large-scale investment in ecological infrastructure enabled farmers to obtain ecological compensation, and agricultural income resulting from land productivity improvement brought about by infrastructure investment. This study further confirms the dual benefits of ecological infrastructure in controlling erosion and improving land productivity, and provides sustainable support for achieving coordinated economic growth and ecological environmental protection through effective management of agricultural ecosystems.

Morphological evolution of the Qingshuigou subaqueous delta of the Yellow River before and after the operation of the Xiaolangdi Reservoir (1997-2007)

The Modern Yellow River Delta has a rich history of geomorphological transformations shaped by frequent avulsions and rapid progradation. However, the delta entered a phase of altered morphodynamics following the construction of the Xiaolangdi Reservoir, which fundamentally restructured sediment transport regimes and seasonal hydrological patterns. These changes have amplified challenges in predicting long-term deltaic evolution under evolving boundary conditions. The Qingshuigou Subaqueous Delta, as a major depositional zone, provides a compelling lens to examine these morphodynamic processes. However, seasonal variations in riverine sand transport fluxes driven by the water-sand regulation scheme that accompanied the construction of the Xiaolangdi Reservoir and its impact on the evolution of the delta front are particularly understudied. This study developed a simplified long-term morphodynamic model of the Qingshuigou Subaqueous Delta to investigate its response to riverine water and sediment discharges from 1997 to 2007. The findings are as follows: (1) The morphological evolution of the Qingshuigou Subaqueous delta has gradually changed from the pattern of “leading edge deposition and localized near-shore erosion” before the construction of the Xiaolangdi Reservoir to the pattern of “enhanced leading edge deposition and increased near-shore erosion” after the construction. (2) The construction of Xiaolangdi Reservoir has weakened the spatial distribution of the erosion process to a certain extent, changing the spatial distribution dominated by the erosion process (63.8% of area) before the construction to the spatial distribution dominated by the accretion process (More than 50% of area) after the construction. (3) The spatial and temporal variability of the incoming sediments leads to a significant coarsening of the grain size of the tidal flats in the southern part of the abandoned delta, which in turn maintains a relatively steady state of the shoreline variability. In contrast, the abandoned sand spit experiences severe erosion and depositional fluctuations due to intensified wave action. (4) The study emphasizes the importance of considering seasonal variations in unsteady discharge in modeling the long-term evolution of the delta. It provides new insights into the spatial and temporal differentiation of the geomorphic equilibrium of the Yellow River Delta and contributes to a broader understanding of delta evolution.

Morphological characteristics of permanent gullies and their relationship with topography in two typical agro‐geomorphic regions of Northeast China

AbstractGully erosion poses significant challenges to land degradation and food security. The Mollisols region of Northeast China (MNC) is the main grain‐producing region in China. The low mountainous and hilly region (MFI) and the rolling hilly region (RFI), as the prominent topographic units in MNC, have suffered significantly from severe gully erosion. However, the actual situation and influencing factors of gully erosion in both regions are still unclear. Thus, we selected two field investigation regions of 103.4 km2 in MFI and 123.9 km2 in RFI to obtain a detailed inventory of gullies. Results showed that the gully number density in MFI was 25.7 No. km−2, 8.3 times greater than in RFI. Conversely, the gully average gully length (511.7 m), width (7.8 m) and depth (2.8 m) in RFI were 156.8%, 112.6% and 37.4% greater than those in MFI, respectively. The three types of gullies, developed in different land uses (GF, farmland; GW, woodland; GR, unpaved road), had significantly varying morphologies. In RFI, GF was the longest, and GW was the widest and deepest. Conversely, in MFI, GR was the longest but exhibited the least width and depth. Notably, farmland posed the highest risk of gully erosion in both MFI and RFI, with 74.4% and 89.6% of the gullies developed there, respectively. Topography was the critical factor influencing the differences in gully erosion between the two regions. To effectively control gully erosion, topographic conditions most susceptible to gully erosion should be prioritized for attention, e.g., slopes of 8–10° and 2–4° were the slope intervals most likely to contribute to gully development in MFI and RFI, respectively. We provide the potential for large‐scale prediction of gully erosion. Corresponding prediction models based on gully area were provided and the effectiveness of the predictions was improved by separating different land uses. The study's findings could serve as a valuable foundation for gully erosion control and prediction for MNC.

Prioritizing public resources for riverbank erosion protection: A decision support framework

Riverbank erosion poses a significant threat to communities, particularly in flood-prone regions. Protecting riverbanks along large rivers is challenging due to limited public funding allocated by the government to address erosion points. This creates an urgent need for an efficient resource management strategy. This research aims to develop a decision-support framework for the optimal allocation of public resources to protect vulnerable areas affected by erosion along the Sinu River in Colombia. The optimization model prioritizes interventions at affected erosion points based on various factors such as community vulnerability, erosion severity, available budget, and intervention effectiveness. The model is validated through a case study on the Sinu River, demonstrating its potential to minimize risks and improve resource allocation efficiency. The study concludes that the developed framework can significantly enhance decision-making processes in riverbank erosion protection, providing a decision-support tool for managing limited public resources.

Investigating the resistance to severe environmental erosion of modified Pisha sandstone composite materials

Investigating the resistance to severe environmental erosion of modified Pisha sandstone composite materials

Changing Extreme Precipitation Patterns in Nepal Over 1971–2015

AbstractThis paper provides a comprehensive and comparative analysis of extreme precipitation patterns from 1971 to 2015 in Nepal, a data scarce, but “hot spot” region in global climate change. We compare in‐situ observations and gridded precipitation data from the Asian Precipitation Highly Resolved Observational Data Integration Toward Evaluation of Water Resources (APHRODITE). Using 11 precipitation indices, we show that high‐intensity (RX1day, R95pTOT, R99pTOT) and frequency‐related indices (R10 mm, R20 mm) have decreased but annual maximum consecutive dry and wet days have increased. Observations affirm these trends found by the APHRODITE, but show smaller magnitudes likely due to differences in measurements at locations made below the 3,000 m elevation line. Spatially, the relatively dry western region has become wetter, and the relatively wet eastern region has become drier post‐2003. The weakening of the South Asia Monsoon circulation, particularly assessed by the Webster and Yang Monsoon Index, correlates strongly with extreme precipitation indices. Changes in upper‐level jet and associated lower‐level monsoon trough are identified as critical factors influencing the extreme precipitation trend post‐2003. This study is the first to confirm the efficacy of APHRODITE in providing spatial and temporal precipitation patterns in a data‐limited region. We conclude that monsoon weakened circulations and changes in regional wind fields play dominant roles in the long‐term temporal and spatial trends of extreme precipitation in Nepal. The reduced precipitation extremes in the wet eastern region may somewhat lessen severe flooding and erosion, but the drier western region may face heightened risks in precipitation‐related hazards in Nepal.

Mitigating rainfall induced soil erosion through bio-approach: From laboratory test to field trail

Extreme rainfall events exacerbated by global warming can pose great threats to soil stability, causing severe soil erosion and triggering various disasters, such as landslide, debris flow, and land degradation. This study explores the efficacy and critical influence factors of a bio-approach utilizing microbially induced calcite precipitation (MICP) for soil erosion control by conducting a series of laboratory tests. The field trial was also performed to explore the long-term effectiveness of MICP treatment on soil slope under natural rainfall. The laboratory tests results indicate that the peak penetration strength increased 4.43 times, and the soil slaking index and soil loss during rainfall decreased by up to 65.7 % and 92.6 % after MICP treatment. The optimal concentration of cementation solution was found to be 1.0 M. Both the one-phase and two-phase MICP methods proved effective in enhancing soil erosion resistance. However, the two-phase MICP method demonstrated a more pronounced impact on surface soil improvement, while the one-phase MICP method achieved a more uniform treatment effect. The 11-months field erosion trials validated the remarkbale durability of MICP treatment in controlling soil erosion. Additionally, more cycles of MICP treatment further enhanced the soil erosion resistance to rainfall. The bonding and filling effect of MICP-produced CaCO3 precipitates played a crucial role in the improvement of soil water stability and mechnical strength, thereby significantly mitigating soil erosion caused by raindrop and surface runoff during natural rainfall. This study provides valuable suggestions for the pratical application of MICP approch on soil erosion control against increasing extreme rainfall, which is also expected to offer a controllable and sustainable soil improvement solution under the climate change.

Morphological changes of river Bank Erosion and channel shifting assessment on Arial Khan River of Bangladesh using Landsat satellite time series images

The continuous processes of erosion and deposition in rivers are intricately linked to changes in land use and land cover (LULC), reflecting dynamic landscape transformations. This study investigates the rate of riverbank erosion, channel shifting, and the impact of erosion on LULC dynamics along the Arial Khan River. Utilizing GIS and remote sensing techniques, we analyzed time-series satellite images from 1993 to 2024 within a 2 km buffer zone of the floodplain. Supervised classification methods were applied for LULC analysis, with results validated using confusion matrices to assess classification accuracy. ArcGIS 10.8 was employed to analyze channel centerline migration, while NDVI analysis assessed vegetation health. The study reveals that between 1993 and 2024, 5142.60 ha were lost to erosion, while deposition affected 4756.52 ha, with erosion surpassing deposition overall. The river shifted an average of 0.66 km during this period, with higher migration rates in Muladi Upazila compared to Babuganj Upazila. Settlement areas expanded significantly from 137.82 ha in 1993 to 2768.68 ha in 2024, while agricultural land declined substantially. These findings provide valuable insights for policymakers to address erosion severity in confluence zones and lay the groundwork for sustainable land management practices.

Spatial Assessment of Soil Erosion Risk Using RUSLE and GIS in Dhumuga Watershed, Ambo, Ethiopia

Soil erosion has become a critical problem leading to land degradation and environmental risks globally. To grasp the rates of soil loss and identify the main factors driving these issues, it is vital to examine the specific impacts of soil erosion across different locations. Therefore, between 2021 and 2023, a research initiative was undertaken to assess, rank, identify, and map sections of the watershed that are particularly susceptible to soil erosion. The RUSLE components for factors R, K, L, S, C, and P were integrated using the ArcGIS 10.4.1 spatial analyst's raster calculator tool to calculate and create maps that illustrate the risk and intensity of soil erosion in the Dhumuga watershed. The Dhumuga watershed was categorized into five groups based on average annual soil loss: 0–5 ton/ha<sup>-1</sup> year<sup>-1</sup> (very slight), 5–10 ton/ha<sup>-1</sup> year<sup>-1</sup> (slight), 10–20 ton/ha<sup>-1</sup> year<sup>-1</sup> (moderate), 20–50 ton/ha<sup>-1</sup> year<sup>-1</sup> (high), and > 50 ton/ha-1 year-1 (very high). The assessment of soil erosion severity was influenced by factors such as rainfall, soil type, DEM, land use, and land cover, employing the GIS-based RUSLE equation. The spatial risk of soil erosion was sorted into five categories based on severity, with 11.58% of the area categorized as very high risk (>50 ton ha<sup>-1</sup> year<sup>-1</sup>), and 54.2% in the very low to low-risk category. On average, the watershed yielded an annual sediment production of up to 13.94 tons/ha/year, which is within an acceptable range. Considering these research findings, GIS-based analyses can be utilized to pinpoint areas at risk of soil erosion and identify vulnerable zones, offering crucial insights for future soil conservation and model enhancement.

Ecosystem Services’ Response to Land Use Intensity: A Case Study of the Hilly and Gully Region in China’s Loess Plateau

The hilly and gully region of the Loess Plateau represents one of China’s most ecologically vulnerable landscapes, characterized by severe soil erosion, intensive land use, and pronounced disturbances to the structure and functionality of ecosystem services. Taking Zichang City as a case study, this research integrates grid-scale analysis with the InVEST-PLUS model and bivariate spatial autocorrelation techniques to examine the spatiotemporal dynamics and inter-relations of four critical ecosystem services—carbon storage, water yield, biodiversity, and soil retention—under varying land use intensity scenarios from 1990 to 2035. The findings indicate that (1) between 1990 and 2020, land use intensity in Zichang City steadily declined, exhibiting a spatial distribution pattern typified by central-area clustering and gradual peripheral transitions. (2) Across three development scenarios, the spatial distribution of the four ecosystem services aligned with the patterns observed in 2020, with central areas showing pronounced fluctuations, whereas peripheral regions experienced relatively minor changes. Specifically, from 1990 to 2020, the proportion of low-carbon storage areas increased by 2.89%, and high water yield areas expanded by 9.45%, while the shares of low habitat quality and low soil retention areas decreased by 5.59% and 6.25%, respectively. (3) A significant spatial autocorrelation was observed between land use intensity and the four ecosystem services, with widespread cold and hot spots reflecting dynamic spatial clustering patterns. These results offer valuable insights for optimizing land use strategies, improving ecosystem service performance, and advancing ecological conservation and sustainable development initiatives.

Durability of Basalt fiber-reinforced aeolian sand concrete in extreme environments: Resistance to wind-sand erosion and salt freeze-thaw cycles

This study investigates the mechanical properties and durability of basalt fiber aeolian sand concrete (BF-ASC) under wind-sand erosion (WSE) and salt freeze-thaw cycles (SFTC). The research explores the individual and combined effects of basalt fiber (BF) content (0.10 %, 0.15 %, 0.20 %) and aeolian sand (AS) substitution ratios (20 % and 100 %) on concrete properties. Mechanical tests include compressive, splitting tensile, and flexural strength, while durability tests focus on WSE and SFTC resistance. Base on the experimental results, several major findings are undisclosed. It is found that concrete with 20 % AS replacement and 0.15–0.20 % BF content significantly exhibits enhanced mechanical- and durability- related properties. A three-dimensional blue light scanning technique effectively quantifies the surface damage of AS concrete after WSE, demonstrating that 20 % AS based concrete has the least surface porosity and higher stability in surface roughness post-erosion, while 100 % AS concrete shows severe erosion effects, including mortar detachment and increased pitting. Moreover, the characterizations at the microstructural level demonstrates that a content AS incorporation (20 %) improves internal structure and hence the SFTC durability, with less pores and cracks compared to the companion conventional concrete. This research contributes vital insights into BF-ASC behavior under extreme conditions, offering guidance for optimal mix designs in harsh environments. The findings have significant implications for sustainable construction practices, particularly in regions facing challenges of desert sand utilization and severe environmental conditions.

Identifying Soil Erosion-Prone Areas in the Wadi Haly Catchment, Saudi Arabia Using Morphometric Analysis and Watershed Features

Soil erosion has several significant impacts on human and environmental activities that make it an important topic with significant worldwide ramifications. Analyzing morphometric indices provides essential insights into watershed geomorphology, which is key to forecasting and assessing diverse natural hazard dynamics. To ensure effective and sustainable watershed management and resource distribution, it is essential to identify critical catchments or prioritize sub-catchments. In this study, morphometric analysis and prioritization were applied to 15 sub-catchments within the Wadi Haly catchment to identify the one most susceptible to soil erosion. This research focuses on the analysis of 15 sub-catchments within the Wadi Haly catchment in Saudi Arabia, utilizing GIS tools alongside various parameters to guide both short- and long-term catchment management. A combined parameter, developed from several morphometric indices for each sub-catchment, was used to classify the Wadi Haly catchment into three levels of soil erosion risk. The results show that sub-catchments 1, 7, 11, 12, and 13, with areas of 694.1 km², 517.87 km², 677.99 km², 200.39 km², and 326.55 km², respectively, are contributing significantly to erosion in the region. In contrast, sub-catchments 3, 8, 9, 10, and 15 exhibit minimal erosion impact. To mitigate severe erosion, strategies such as contour farming, terracing, the use of filter strikes, as well as various structural or non-structural interventions could be applied.

Spatial–Temporal Evolution Pattern of Soil Erosion and Its Dominant Factors on the Loess Plateau from 2000 to 2020

Global changes have led to significant changes in soil erosion on the Loess Plateau. Soil erosion leads to the degradation of land resources and a decline in soil fertility, adversely affecting agricultural production and the socioeconomic situation. Therefore, revealing the spatiotemporal evolution patterns of soil erosion in the Loess Plateau region and investigating the influencing factors that contribute to soil erosion are crucial for its management and restoration. In this study, the RUSLE monthly model and the Geodetector model were utilized to reveal the spatiotemporal trends of soil erosion in the Loess Plateau from 2000 to 2020 and to determine the dominant influencing factors in different periods. The main results are as follows: (1) From 2000 to 2020, the soil erosion in the Loess Plateau initially weakened and then intensified, indicating that precipitation and precipitation intensity have different effects on surface soil. (2) From 2000 to 2015, the area experiencing slight and mild erosion increased. This is attributed to the increase in vegetation coverage in the Loess Plateau region, which has alleviated soil erosion in the area. (3) From 2000 to 2020, zones of severe soil erosion were mainly located in the cities of Yan’an and Yulin and their surrounding areas. The gravity center of soil erosion shifted northwestward from Yan’an City overall, indicating an improvement in the soil erosion conditions in the Yan’an area. (4) The predominant level of soil erosion across different land-use types was slight erosion, accounting for over 40%. This may be a result of forestry ecological projects that effectively reduce soil loss. (5) In slope zones of 0–5°, slight erosion accounted for the largest area proportion. As the slope increased, the area proportion of severe and extremely severe erosion also increased. This is attributed to the protective role of vegetation on soil in gentle slope areas. (6) From 2000 to 2020, vegetation was the dominant single factor influencing the spatiotemporal changes in soil erosion, while the interactions between vegetation and land use had the largest explanatory power, indicating that changes in land-use types partially affect variations in vegetation coverage. Our research findings could provide important data support for soil erosion control and eco-environment restoration in the Loess Plateau region.

Numerical Prediction of Solid Particle Erosion in Jet Pumps Based on a Calibrated Model

Jet pumps are widely used in petrochemical processes, nuclear cooling, and wastewater treatment due to their simple structure, high reliability, and stable performance under extreme conditions. However, when transporting solid-laden two-phase flows, they face severe erosion problems, leading to reduced efficiency, malfunctions, or even failure. Therefore, optimizing jet pump performance and extending its service life is crucial. In this study, an experimental platform was established to conduct experiments on wall erosion in jet pumps. The CFD-DEM method was used to simulate the solid–liquid two-phase flow in the jet pump, comparing six erosion models for predicting erosion rates. The Grey Wolf Optimization algorithm was applied to calibrate model coefficients. The results indicate that the Neilson erosion model shows the best consistency with the experimental results. The inlet flow rate significantly influenced the erosion rates, while the flow rate ratio had a smaller effect. The particle concentration exhibited a nonlinear relationship with erosion, with diminishing impact beyond a certain threshold. As the factors varied, the erosion distribution tended to be uniform, but high erosion areas remained locally concentrated, indicating intensified localized erosion.

Bilateral TMJ Changes Secondary to Unilateral Condylar Hyperplasia

Background: Patients with unilateral condylar hyperplasia (UCH) may present with TMJ symptoms, rather than concerns or recognition of asymmetry. Localization of TMJ pain may be on the affected (long) side, unaffected side, or both. Flattening, severe erosion and internal derangement on the opposite side can be appreciated radiologically. This can be a red herring, shielding the true diagnosis of UCH from the contralateral side. We hypothesize that excessive growth of the ipsilateral condylar neck and head on the side of UCH results in an upward and backward force on the opposite side TMJ, with resultant symptoms and findings (condylar flattening, anterior disk displacement, eminence changes). The purpose of this paper is to highlight the bilateral TMJ findings in UCH, and address potential treatment strategies. Methods: This is a retrospective study involving radiologic and biographical data from subjects with TMJ UCH, as well as controls. Patient details and high quality Cone beam CT (CBCT) scans (1 mm slices or less) were analyzed. CT scans were digitized and morphometric points were placed using Planmeca software (Hoffman Estates, Illinois). Linear and volumetric measures were taken in reference to the eminence, TMJ space, condylar position, and neck lengths. Volumetric analysis of the condylar head and neck was done using Analyze 14.0 software (Overland Park, KS, USA). Results were assessed using univariate analysis (T-Wilcoxon test). Results: Forty patients were included (29 with UCH, 11 controls). The condylar head was flatter and erosive appearing on the contralateral UCH side compared to both ipsilateral side in the same subject, and compared to controls. Analysis between the affected and unaffected sides in patients with UCH showed a significant difference in condylar head and neck length ( P = .0019) and volume ( P = .0030); anterior glenoid space ( P = .035) and vertical height of condylar eminence ( P = .00044). The difference in ramus length was not significant ( P = .6533). Between the controls and the UCH patients, there was a significant difference in the variance in condylar head and neck length ( P = 1.98e-07) and volume between the 2 sides ( P = 1.94e-08) but not ramus length ( P = 1). The vertical height of the condylar eminence was smaller on the affected side than in the controls ( P = .0018) and the anterior glenoid space was significantly smaller on the unaffected side compared to the controls ( P = .0053). Conclusion: This study highlights TMJ morphological differences in patients with UCH. These differences in condylar and glenoid morphology are consistent and should be used to aid and underpin the diagnosis and direct treatment. Importantly, patients who present with TMJ pain and erosion on one side, should be assessed for opposite side UCH, as the underlying culprit.