Distribution Of Erosion Research Articles

Advanced high‐precision methodology for assessing sediment erosion in Pelton turbine buckets

AbstractDeveloping highly accurate sediment erosion testing methods for Pelton turbine overflow components is challenging due to their irregularly curved surfaces. In this study, we designed a method to evaluate the sediment erosion of the Pelton turbine bucket using test blocks with an accuracy of 0.0001 g. In addition, we conducted sediment erosion tests on a model Pelton turbine and conducted an in‐depth study on the installation design of the turbine runner and bucket, the design of the erosion test blocks, and the arrangement; we analyzed sediment abrasion distribution on the bucket's working surface. Our test results show that the bucket splitter edge, as well as the root of the working surface, are heavily worn. The maximum erosion rate of the working face is 0.7669 μm/h, and the maximum erosion rate of the splitter edge is close to 5 μm/h, which is highly consistent with the distribution of sediment erosion observed in Pelton turbines operating under sandy river conditions. This test method is essential for examining sediment erosion in Pelton turbines.

Characteristics and driving factors of spatiotemporal changes in soil erosion in the karst plateau mountainous region over 20 years.

Soil erosion is one of the main issues that endangers global ecosystems. This study explored the spatiotemporal distribution of soil erosion and its drivers in the karst plateau mountainous region. A detailed examination of topography, soil, vegetation, land use, and precipitation data from 2000 to 2020 was conducted in Bijie City using the revised universal soil loss equation model. We also explored the driving forces using a geographical detector. The findings show that between 2000 and 2020, soil erosion first decreased, followed by an increase. The southwest, south, and northern regions contained the highest intensity of soil erosion. Land use, slope, and precipitation are the primary factors influencing soil erosion, with slopes having the greatest impact. By improving our understanding of the dynamics of soil erosion and the primary variables that influence it in karst plateau mountainous environments, our findings can assist in the development of strategies and technical support for sustainable soil and water conservation.

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.

The Assessment of the Spatiotemporal Characteristics of Net Water Erosion and Its Driving Factors in the Yellow River Basin

The Yellow River Basin (YRB) is an important grain production base, and exploring the spatiotemporal heterogeneity and driving factors of soil erosion in the YRB is of great significance to the ecological environment and sustainable agricultural development. In this study, we employed the Revised Universal Soil Loss Equation (RUSLE) in conjunction with Transport-Limited Sediment Delivery (TLSD) to explore a modified RUSLE-TLSD for use assessing net water erosion. This modification was performed using sediment data, and the explanatory power of driving factors was assessed utilizing an optimal parameters-based geographical detector (OPGD). The results demonstrated that the modified RUSLE-TLSD can accurately simulate the spatiotemporal distribution of net water erosion (NSE = 0.5766; R2 = 0.6708). From 2000 to 2020, the net water erosion modulus in the YRB ranged between 1.62 and 5.33 t/(ha·a). Specifically, the net water erosion modulus decreased in the YRB and the middle reaches of the YRB (MYRB), but it increased in the upper reaches of the YRB (UYRB). The erosion occurred mainly in the Loess Plateau region, while the deposition occurred mainly in the Hetao Plain and Guanzhong Plain. The Normalized Difference Vegetation Index (NDVI) and slope emerged as significant driving factors, and their interaction explained 31.36% of YRB net water erosion. In addition, the redistribution of precipitation by vegetation and the slope weakened the impact of precipitation on the spatial pattern of net water erosion. This study provides a reference, offering insights to aid in the development of soil erosion control strategies within the YRB.

Research on the spatiotemporal distribution and control degree of soil erosion in Dali River Basin

The Dali River basin as the representative areas of the middle reaches of the Yellow River. Accurately evaluating the degree of soil erosion control is very important for soil erosion control. In response to the problems existing in the current research on soil erosion control degree (SECD) methods, the maximum possible soil erosion modulus is introduced into the evaluation model. Thereby eliminating the uncertainty of the assumed state of the original model. This paper calculates the SECD for 2020 based on this method. The results show: (1) From the soil erosion modulus spatial distribution, it can be seen that the soil erosion intensity is stronger in the eastern and southwestern parts. (2) Based on the SECD spatial distribution, it was found that eastern and southwestern regions were well controlled. This is consistent with the actual situation. (3) As the slope increases, the area proportion of SECD within the 0.2-0.3 range in each slope zone shows an increasing trend, while that of SECD within the 0.5-1 range gradually decreases; (4) In the case of vegetation coverage greater than 80%, SECD is still concentrated between 0.3-0.5, which indicates that vegetation coverage is not the only factor affecting soil erosion control. This research provided a new perspective for the evaluation of SECD.

Large-scale variability in style and magnitude of footwall rift-related unconformities, northern Carnarvon Basin, offshore NW Australia

Fault-scarp degradation complexes record rift-related erosion of normal fault scarps. At the scale of an individual fault segment, the magnitude and distribution of erosion are related to the total and along-strike variability in fault throw. However, previous studies on degradation complexes focused on one type of rift-related erosional unconformity, with the factors controlling the development, magnitude and style of footwall erosion at a far larger scale (i.e. several fault blocks) being poorly constrained. This study uses high-resolution subsurface data to constrain the timing, magnitude and style of footwall erosion across the NW Shelf of Australia. By doing so, we test conceptual and numerical model predictions for the development of rift-related unconformities. We show that development of footwall erosion complexes is dependent on the occurrence and duration of footwall exposure and that fault throw and footwall uplift control the magnitude of erosion. Furthermore, the style of footwall erosion depends on the driving process(es), with gravitational instabilities resulting in cuspate footwall crest erosional surfaces, whereas peneplain-style surfaces develop in response to wave-driven erosion dictated by the base level. The results of this study can help refine rift-related fault evolution and the effects of sea-level changes in tectonostratigraphic models of rift basins.

A numerical assessment of different geometries for reducing elbow erosion during pneumatic conveying

This paper investigates wear characteristics in a dilute phase pneumatic conveying pipe system using a Euler-Lagrange method. Simulations couple computational fluid dynamics (CFD) with the discrete element method (DEM) to analyze three different bend geometries, including two erosion-reducing designs and a standard bend, all with an effective bend radius to pipe diameter ratio (R/D) of 1.5. SiO2 particles, 1 mm in diameter, are conveyed at gas velocities of 15 to 30 m/s and mass loadings of 1 to 4 kgparticle/kggas. The CFD-DEM predictions were validated against experimental data, showing good agreement in erosion distribution. The study evaluates erosion rates, pressure drops, and particle stressing for the three bends. Results suggest that certain bend designs significantly reduce erosion while slightly increasing pressure drop, although reduced particle-wall erosion may increase the overall particle stressing. The obtained results provide guidance on selecting an appropriate bend design and for potential geometry optimizations.

Insights into the relationship between particulate flow characteristics and local erosion behaviour under waterjet: The role of particle-fluid-surface interaction

In this study, the erosion characteristics of eutectic high entropy alloy under the liquid–solid two-phase flow is investigated by a coupled numerical-experimental method, in order to reveal the intrinsic relationship between microscopic erosion mechanism (experimental test) and the related particle-fluid-surface interaction (CFD modelling). Furthermore, instead of the common relation between average erosion rate and mainstream flow velocity, the relationship between local erosion distribution and local particulate flow characteristics is clarified. The erosion rate and erosion pattern match well between the experiment and simulation. The results demonstrate that NiCoCrFeNb0.45 exhibits superior anti-erosion performance when compared to other widely used equipment metals. The erosion profile agrees well with the shape of surface velocity distribution, indicating a close relationship between surface erosion behaviour and flow characteristics. In particular, the erosion pattern at a normal angle appears as a symmetric ring due to the flow stagnation phenomenon, with slight erosion damage in the centre area and severe erosion in the surrounding, whereas the erosion profile at an oblique angle displays an elliptic shape, with severe erosion damage in centre. Notably, the primary erosion mechanism varies dramatically in different surface regions, induced by the various impact velocities and angles associated with the corresponding changes in the flow field. This study provides a deeper understanding of erosion behaviour in terms of the interrelationship among the material mechanical properties, particulate flow field and particle-surface impingement behaviour.

Analysis of the coupling and coordination between soil erosion and land use in the Northeastern black soil region of China: a case study of Lishu County

Lishu County, which is located in the black soil region of Northeast China, represents a key site for the analysis of soil erosion intensity. This study offers a scientific foundation for the development of targeted soil and water conservation strategies within the region. The Revised Universal Soil Loss Equation (RUSLE) was employed to compute the soil erosion modulus in Lishu County, with the objective of conducting a quantitative analysis of the temporal and spatial distribution patterns of soil erosion. Additionally, the changing characteristics of soil erosion were examined from the perspectives of land use types and slope variations. The Generalized Connectivity Causality Model (GCCM) was utilized to identify the causal relationship between soil erosion and land use types through the reconstruction of state space and cross-mapping predictions. (1) Soil erosion in Lishu County between 2000 and 2020 predominantly exhibited mild to moderate levels, characterized by patchy and sporadic erosion, with relatively severe occurrences in the northern and central regions. (2) Soil erosion was correlated with land use and slope variations, with more than 90% of erosion incidents transpiring in cultivated land areas. The 3°-5° slope range in Lishu County emerged as a focal point for erosion, necessitating targeted prevention and control measures. (3) The GCCM model illustrated a discernible causal relationship between soil erosion and land use, revealing mutual influences between the two factors. Between 2000 and 2020, both the area and intensity of soil erosion in Lishu County exhibited an initial increase, followed by a subsequent decrease. This suggests an overall trend of amelioration in soil erosion conditions. However, notable spatial disparities persist in the erosion distribution across the region.

Estimation of soil loss using RUSLE model and GIS tools: Case study in the Jucusbamba Micro-Watershed (Amazonas, NW Peru)

Human activities have intensified soil erosion globally, negatively impacting the physical, chemical, and microbiological quality of water and soil. This study estimated soil loss in the Jucusbamba Micro-Watershed (Amazonas, northwestern Peru) using the Revised Universal Soil Loss Equation (RUSLE) integrated with Geographic Information Systems (GIS) and remote sensing (RS) data. Meteorological data, soil maps, digital elevation models, and land cover and use maps were integrated into a GIS environment to predict the spatial distribution of erosion. The results showed five classes of soil loss severity: slight (93.34%), moderate (3.94%), high (1.82%), very high (0.61%), and severe (0.29%). Areas with high, very high, and severe erosion levels were mainly located in the middle and lower parts of the micro-watershed. The average annual soil loss was estimated at 23.24 t/ha/year. The information obtained is crucial for the formulation of soil management plans and programs to address erosion problems in the Jucusbamba River Micro-Watershed. Future research should focus on validating these models through field studies and implementing soil conservation practices based on these findings. Keywords: Amazonas, hydrology, RUSLE model, water erosion map, watershed.

Spatio-temporal evolution of water erosion in the western Songnen Plain: Analysis of its response to land use dynamics and climate change

Preventing water erosion is crucial for maintaining ecosystems and ensuring food security, necessitating a comprehensive understanding of the spatial and temporal patterns of water erosion and its underlying drivers. In the context of global warming, analyzing the impacts of land use dynamics and climate change on water erosion contributes to effective land management and sustainability of both industry and agriculture. This study aims to analyze the spatial distribution of water erosion in the western Songnen Plain from 1990 to 2020 using the Revised Universal Soil Loss Equation (RUSLE), with a focus on assessing the impacts of land use and climate on water erosion. The results revealed a 7.1 % increase in the area experiencing water erosion above light levels in the western Songnen Plain. The hotspots for water erosion were located in the southeast and northwest of the study area. The rapid expansion of farmland and land salinization, leading to reduced vegetation cover and soil property deterioration, were the main causes of intensified water erosion in the region before 2000. Although water erosion was slightly alleviated after 2000, the further expansion of farmland, the worsened water erosion intensity in alkaline land and frequent extreme weather still posed serious threats to water erosion in the study area. Water erosion was positively correlated with temperature and dry/wet alternation events, including frequency, duration, and severity. In addition, land use type was the main factor influencing the heterogeneous distribution of water erosion in the western Songnen Plain, whose interaction with dry/wet alternation events had the strongest explanatory power. Therefore, this study calls for the implementation of soil and water conservation measures to mitigate the impacts of land cultivation, salinization, and climate change on water erosion.

Palaeogeography and 3D variability of a dynamically uplifted shelf: Observations from seismic stratigraphy of the Palaeocene East Shetland Platform

AbstractIn the Palaeocene North Sea, pulses in turbidite fan deposition and shelfal progradation have been correlated with episodes of regional uplift caused by a precursor of the Icelandic Plume. In the East Shetland Platform, the specific impacts of dynamic uplift on the regional palaeogeographic evolution are less understood. Using new, high‐resolution 3D seismic data from an underexplored proximal area, we investigate the palaeogeography of the East Shetland Platform in terms of the extent and timing of erosion versus deposition, focusing on how these can be used to reconstruct changes in relative sea‐level along strike. Using a combination of well data, clinoform‐based seismic stratigraphy and seismic attribute analysis of >60,000 km2 of 3D data, we have obtained palaeogeographic maps of multiple Palaeocene to Early Eocene units, with high temporal resolution for the Late Palaeocene–Early Eocene Moray Group. This includes six unconformity‐bounded units marked by prograding clinoforms of the Dornoch Formation, which are covered by backstepping sequences of the Beauly Member (Balder Formation). Temporal and spatial changes in the distribution of downdip depocentres and updip unconformities indicate strong lateral variability in patterns of shelf accommodation/erosion and local sediment supply. This results from a complex interplay among laterally uneven relative sea‐level fall, inherited topography, time‐varied sediment entry point distribution and along‐shore sediment transport regimes. Unconformities and palaeogeographic maps suggest a first‐order control on erosion and sediment distribution promoted by the transiently and differentially uplifted topography of Shetland, which is characterized by an anomalous erosive history in the Bressay High, in the centre of our study area, where the Lower Dornoch Formation has been eroded and marked fluvial incision is observed. Ultimately, results indicate shorter‐wavelength and shorter‐period variations in uplift than what is typically assumed for dynamic topography, perhaps as a result of additional modulation by lithospheric structures or influence of previous rift‐related faults.

Characteristics of Soil Physical Properties and Spatial Distribution of Soil Erosion on Ridge-Slope Farmland in the Black Soil Areas of Northeast China

Characteristics of Soil Physical Properties and Spatial Distribution of Soil Erosion on Ridge-Slope Farmland in the Black Soil Areas of Northeast China

The effect of dynamic changes in vegetation coverage on the mechanism of organic carbon loss in inter-rill erosion

The intricate effects of dynamic variations in vegetation coverage, representing different vegetation growth states and erosion conditions, on properties (content, enrichment and loss) of sediment and soil organic carbon (SOC) fraction in inter-rill erosion have not yet been fully elucidated. By setting micro-plots with different vegetation coverage ranges (0 %, 15 ∼ 35 %, 25 ∼ 55 % and 35 ∼ 70 %), the interaction mechanisms between vegetation coverage and inter-rill erosion, particle size distribution and SOC fractions properties during the vegetation growing period were studied. The average sediment yield, runoff yield and sediment concentration were highest under the bare plot, and diminished progressively with increased vegetation coverage. The effective clay content decreased with the increasing coverage, while ultimate clay was highest in the vegetation coverage range of 25 ∼ 55 %. Clay particle was transported as aggregates, with enrichment for all treatments except for the vegetation coverage range of 35 ∼ 70 %, providing transportation potential for SOC fractions loss. The content of SOC and mineral-associated organic carbon, as well as their enrichment ratio, decreased and then increased with coverage, which is the opposite of particulate organic carbon, and the loss of all fractions decreased with increasing vegetation coverage. Mineral-associated organic carbon dominated change in SOC, with proportion in SOC content and loss decreasing first and then increasing with vegetation coverage. The structural equation model showed the impact of vegetation coverage on SOC fraction loss was mainly achieved through indirect regulation of inter-rill erosion and particle size distribution. Our results provide new insights into the complex relationship between natural slope vegetation coverage and SOC loss, particularly from a fractions perspective, as well as understanding the ultimate fate of SOC in such environments.

Spatial and temporal distribution and environmental determinants of freeze-thaw erosion intensity in Qiangtang grasslands, China

Context Analysing freeze-thaw erosion is of great significance to ecological environment protection and land resource utilisation in high altitude areas. Aims We used seven indicators (temperature, precipitation, vegetation cover, elevation, slope, slope orientation, and sand content) to calculate the freeze-thaw erosion intensity index for different seasons from 2000 to 2019. Methods We used a graded weighted evaluation model and a geographical detector method to analyse spatiotemporal pattern and driving factors of freeze-thaw erosion intensity in Qiangtang grasslands. Key results (1) From 2000 to 2019, the total area of freeze-thaw erosion was higher in the non-growing season than in the growing season. The area of moderate and above-average freeze-thaw erosion increased over time in the non-growing season but decreased in the growing season. The spatial distribution of freeze-thaw erosion was mainly determined by the annual range of precipitation and temperature, which reflect the intensity and frequency of freezing and thawing cycles. (2) Vegetation cover was an indirect factor that influenced the soil moisture and stability. The slope was another important factor that affected the spatial distribution of freeze-thaw erosion in different regions. Conclusions The results show that in 2000–2019 the area of freeze-thaw erosion showed a downward trend. The erosion degree in the non-growing season is on the rise. Implications Our study provides new insights into the dynamics and mechanisms of freeze-thaw erosion in Qiangtang grasslands and contributes to the understanding and management of water and climate change impacts on this region.

Numerical Study of Solid–Gas Two-Phase Flow and Erosion Distribution in Glass Fiber-Reinforced Polymer Ball Valves

The use of glass fiber-reinforced polymer (GFRP) composites in fluid transport systems can effectively reduce corrosion damage caused by corrosive media. However, collisions between solid particles and the surfaces of ball valve flow passages can cause erosion damage and lead to safety issues. The two-phase flow and erosion characteristics of ball valves manufactured from resin-based fiber-reinforced composite materials were studied under different openings and particle sizes using the CFD-DPM method. The results indicate that both smaller and larger relative openings are prone to erosion damage at the thin edges of the valve ball. As the relative opening increases, the average erosion amount in the flow passage first increases and then decreases. The maximum average erosion amount is 0.0051 kg/m2·s when the relative opening is Cv = 40. At Cv = 40, erosion damage in the flow channel mainly occurs at the bottom of the inlet flow channel and the valve seat position. With increasing particle size, both the average and maximum erosion amounts in the flow channel increase. Larger particle sizes in the inlet flow channel significantly raise the erosion rate nearby, while at other locations, larger particle sizes mainly increase the erosion rate in the same area. During the use of GFRP valves, it is important to avoid introducing large-sized particles into the medium. Keeping the valve’s relative opening greater than 40 and using more erosion-resistant materials for the valve seat can effectively reduce the erosion of the composite ball valve and extend its service life.

Energy characteristics of a deep-sea mining pump under solid-phase interaction

Deep-sea mining pumps (DMPs) are the crucial power equipment for the hydraulic lift deep-sea mining system. The efficiency and sustainability are greatly affected by the particle conveyance capacity and erosion pattern. To investigate the energy performance, particle conveyance capacity, and erosion pattern of the DMP, different inlet particle volume fraction (IPVF) schemes are investigated using the Euler-Euler method. The data indicates that as the IPVF increases, the head and shaft power increase gradually, and the flow rate at the highest efficiency is consistently 1.5Qd. Additionally, the fluctuation range of the conveyance capacity index decreases as the flow rate increases. At an IPVF of 15%, the particles exhibit a backflow phenomenon, resulting in poor particle conveyance capacity. As the flow rate increases, the erosion rate (ER) of the impeller (IMP) decreases and then increases, and the ER of the space guide vane (SGV) gradually decreases, resulting in a more stable flow state. The erosion distribution of the IMP blades is mainly concentrated on the suction surface. The erosion distribution on the SGV blades is primarily concentrated on the middle and rear of the pressure surface, as well as the middle and front of the suction surface.

Remote Sensing Thematic Product Generation for Sustainable Development of the Geological Environment

Remote sensing thematic data products are critical for assessing and analyzing geological environments, while efficient generation of thematic products is also highly significant for achieving corresponding sustainable development goals (SDGs). Currently, remote sensing thematic product generation has problems like low levels of automation and efficiency. Addressing these challenges is imperative for advancing sustainable development within the geological environment. This paper aims to address issues related to the generation of geological environment remote sensing thematic products, sorting through the overall process of remote sensing thematic product generation, exploring algorithm encapsulation, combination, and execution under technical methods for container and workflow, and relies on the Spark distributed processing architecture to achieve efficient thematic product generation supported by multiple geological environment data processing models. Finally, taking the three SDGs of SDG6, SDG11, and SDG15 as examples, we achieved the generation of a variety of thematic products such as the interpretation of water body distribution, extraction of urban informal settlements and distribution of water and soil erosion. Meanwhile, we comparatively analyzed the efficiency of thematic product generation on different processing architectures, and the experimental results further verified the feasibility and effectiveness of our proposed solution. This research provides a programme for the automated and intelligent generation of geological environment remote sensing thematic products and effectively assists the construction of sustainable development in the geological environment.

A geospatial approach-based assessment of soil erosion impacts on the dams silting in the semi-arid region

Soil erosion significantly impacts dam functionality by leading to reservoir siltation, reducing capacity, and heightening flood risks. This study aims to map soil erosion within a Geographic Information Systems (GIS) framework to estimate the siltation of the K'sob dam and compare these estimates with bathymetric observations. Focused on one of the Hodna basin’s sub-basins, the K'sob watershed (1477 km2), the assessment utilizes the Revised Universal Soil Loss Equation (RUSLE) integrated with GIS and remote sensing data to predict the spatial distribution of soil erosion. Remote sensing data were pivotal in updating land cover parameters critical for RUSLE, enhancing the precision of our erosion predictions. Our results indicate an average annual soil erosion rate of 7.83 t/ha, with variations ranging from 0 to 224 t/ha/year. With a typical relative error of about 13% in predictions, these figures confirm the robustness of our methodology. These insights are crucial for crafting mitigation strategies in areas facing high to extreme soil loss and will assist governmental agencies in prioritizing actions and formulating effective soil erosion management policies. Future studies should explore the integration of real-time data and advanced modeling techniques to further refine these predictions and expand their applicability in similar environmental assessments.

Soil surface erosion susceptibility analysis using the USLE model. Case study: Bran - Dragoslavele Corridor, Romania

The present study falls within the scope of the analysis of the morphodynamic potential of the Bran - Dragoslavele Corridor (Romania), a low mountain area, favorable to erosion processes due to the high energy of the relief, diversified lithology, tectonic complexity, and due to the variation in the energy of atmospheric risk phenomena. For the expansion of pastoral agricultural areas and those intended for human settlements, the deforestation of the last 3-4 centuries deprived the slopes and the soil of the protective forest cover on an area of 55.44%, favoring the amplification of the action of natural morphodynamic agents. In this context, the quantitative and spatial assessment of sheet erosion, expressed as the average annual rate of surface soil erosion (measured in tons hectare–1) was approached by applying the calculation model implemented in the GIS environment by using the universal soil loss equation (USLE). Implementation of the model was realized through the spatial delimitation of the potential erosion and the rendering by susceptibility classes of the quantitative results which reveal the fact that the largest surface of the studied mountain unit (91.68%) presents tolerable values, of 0-1.5 t ha–1 year–1. The highest values, over 4 t ha–1 year–1 (1.24%), are characteristic of the calcareous areas belonging to the many sectors of the gorges with discontinuous vegetation, as well as the limestone exploitation area from Mateiaș mountain. The quantitative knowledge and spatial distribution of surface erosion becomes important for communities and local authorities, interested in the planning and management of the implementation of some agrotechnical measures to improve the quality and productivity of soils or to prevent and restrict erosion processes with a tendency to expand areally and in depth.