Total Erosion Research Articles

Detecting New Erosions in Rheumatoid Arthritis over One Year - Radiography and High-Resolution Computed Tomography of Finger Joints.

To compare the number of new erosions in two metacarpophalangeal (MCP) joints over one year assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) and conventional radiography (CR). Furthermore, to estimate the diagnostic accuracy of erosive progression by CR with HR-pQCT as the reference standard. Paired sets of image data were available from patients with RA (n=310), who underwent HR-pQCT and CR, including the 2nd and 3rd MCP joints only of the dominant hand at baseline and at the one-year follow-up. Erosion number was determined using HR-pQCT and CR. Erosive volume was estimated from segmented HR-pQCT images, and erosion scores were obtained by the Sharp/van der Heijde method from CR. Erosive progression was defined as an increase in total erosion number or a study-specified increase in total erosive volume or total erosion score. At baseline, 250 erosions were identified by CR compared to 1864 erosions by HR-pQCT. After one year, 3 new erosions were detected by CR compared to 66 new erosions by HR-pQCT. Erosive progression was identified in 40 patients using HR-pQCT and in 3 patients using CR. With HR-pQCT as reference, CR had a sensitivity of 2.5% (95% CI: 0.1-13.2%) and a specificity of 99.3% (95% CI: 97.3-99.9%) for detecting erosive progression. HR-pQCT identified more than 20 times the number of new erosions, and more than 10 times as many patients with erosive progression than CR. HR-pQCT is a sensitive tool for monitoring new erosions and erosive progression over one year in RA.

Cavitation erosion behaviour of MAB-CU4 alloy: influences of cavitation number, attack angle, time, and stand-off distance

Abstract The present study comprehensively examines the cavitation erosion behaviour of a manganese aluminium bronze alloy (MAB-CU4 alloy) as a function of several parameters (i.e., cavitation angle, cavitation number, time, and stand-off distance), particularly focusing on the influences of cavitation angle on the surface morphology and topography of the alloy. According to the design of experiment (Taguchi experimental design) analysis, mass loss increased with cavitation number and attack angle, while increasing the stand-off distance resulted in a decrease in mass loss and an increase in the surface area affected by cavitation erosion. Cavitation erosion behaviour was most affected by the cavitation attack angle, with the cavitation attack angle contributing 69.1% to total erosion, according to variance analysis. At 90° cavitation attack angle, MAB-CU4’s erosion rate was 64% greater than that at 30°. Scanning electron microscopy and optical profilometry revealed that cavitation erosion damage at 90° occurred mostly in the grain interiors as cavitation pits due to severe plastic deformation and surface corrosion, whereas pit formation was restricted around the hard secondary phases at the grain boundaries. At 30°, deep cavitation pits were limited, the erosion crater expanded, and the number of pits was reduced. Overall, finer microstructures with more grain boundaries and secondary phases may improve cavitation erosion resistance at 90°. The present study is the first to comprehensively capture erosion damage at the microstructural scale and analyse the impact of microstructural features on the erosion damage during the cavitation erosion of MAB-CU4 alloy.

Global Wind Erosion Reduction Driven by Changing Climate and Land Use

AbstractWhile significant progress has been achieved in researching water erosion, our understanding of global patterns and the magnitude of wind soil erosion remains limited. Here, we present a comprehensive assessment using the revised wind erosion equation (RWEQ) of the global rates and long‐term trends (1982–2019) of wind erosion using a spatially explicit (0.05° × 0.05°) quantitative model. On average, in this study global wind erosion caused 312.5 Pg yr−1 of soil loss, with a decreasing trend of 1.04 ± 0.48 Pg yr−1 (p < 0.05) during 1982–2019. Excluding stable regions, approximately 36% of the modeled areas exhibit a significant decrease in wind erosion, accounting for 3.13 ± 0.18 Pg yr−1, while only 9% experience a notable increase, amounting for 1.83 ± 0.16 Pg yr−1. The decrease of wind erosion primarily occurs in the southern hemispheres. Notably, wind erosion decreases considerably in grassland and cropland, while it remains unchanged in dryland. Although grassland and cropland account for only 11% and 1.8% of the total erosion, they contribute to 68% and 17% of the total erosion reduction, respectively. This study highlights global wind stilling and vegetation greening as important factors contributing to the decline in wind erosion and offers valuable insights into the intricate relationship between climate change and terrestrial ecosystems, including carbon sequestration and agricultural productivity.

Technical Assessment Of Mud Handling Planning With Dredger Pump In Mining Front Area Of Pt. Makmur Lestari Primatama, Southeast Sulawesi, Indonesia

The high intensity of rain can affect mining activities because rainwater will be collected and stored in the area with the lowest elevation. In mining areas that have the lowest elevation point, namely the pit area, this will have an impact on mining activities. The pit area will not be disturbed if water or eroded slopes will enter and be accommodated in well-made drainage and vice versa if drainage is not formed properly, water and mud will be retained and accommodated in the pit area. If the water and mud are left unchecked, the water will overflow and mining will be temporarily halted, affecting the previously planned mining system. In this case, the pit whose water has been pumped out leaves the mud at the bottom of the pit trapped, so action is needed to remove the mud from the pit area and the need for qualified tools according to the existing mud criteria. The mud at PT Makmur Lestari Primatama has an SG criteria of 1.39 (top elevation mud) - 1.5 (bottom elevation mud) with mud grains of 0.005mm to 2mm, it can be concluded that the mud has liquid mud criteria to hard mud. So that the determination of a tool to be able to move mud using a pump, the selection of this pump There are three important parameters: Grain size, Specific Gravity, and also variations in material concentration that must be considered because they can affect the total head or flowrate. The difference between the Slurry pump and the dredger pump is in the pumping process, the dredger pump is able to pump hard mud with the help of a little water while the slurry pump is difficult to pump hard mud because it requires quite a lot of water to pump it. Therefore, a dredger pump is chosen to move the mud in the mining area so that it can pump liquid mud to hard mud, the selection of this dredger pump is based on pump specifications including max capacity 120-200m3/h, solid handling 35mm - 60mm, speed 1180 RPM, and effieciency 46%-51%. The planning analysis of the use of dredger pumps uses the Bernoulli equation and the amount of mud that must be pumped using the USLE method. Based on the results of a series of studies that have been carried out, researchers found that the total potential erosion is 8,574.2 tons/year, the total actual erosion is 7,716.8 tons/year, and the total volume of mud that must be pumped is 5,074.86m3 with a slurry weight of 1,448.2 kg/m3. So the most ideal dredger pump for this purpose is Dragflow HY85A with a capacity of 210m3/h, pumping hours of 16.6 hours / day, pumping duration of 2 days 15 hours and efficiency of 40% using HDPE type 10 inch diameter pipe.

Soil erodibility and hillslope erosion processes affected by vegetation restoration duration

Restoring vegetation is an effective way to control regional erosion as well as reduce soil erodibility. However, it is not clear how the vegetation restoration duration affects soil erodibility and how it further influences soil erosion processes. Therefore, the soil physicochemical properties and comprehensive soil erodibility index (CSEI) at five sampling sites with 3, 20, 55, 80 and 100 years of vegetation restoration were investigated in this study. A simulated rainfall with intensities of 60, 90, and 120 mm h−1 was conducted on three slopes with gradients of 10°, 20°, and 30° by using rare earth element oxides (Ho2O3 and Sm2O3) as tracers to quantify interrill and rill erosion. The results revealed a decreasing trend in both the CSEI and sediment concentration with increasing vegetation restoration duration. Compared to that at the site with 3 years of vegetation restoration, the CSEI at the sites with 20, 55, 80, and 100 years of restoration was reduced by 35.2 %, 39.7 %, 92.8 %, and 67.1 %, respectively. Interrill erosion dominated the hillslope erosion processes and contributed more than 76.9 % to the total erosion amount. By comparing the measured and estimated erosion rates using the equations provided by the Water Erosion Prediction Project (WEPP), significant prediction errors were found. Therefore, relationships among the CSEI, slope gradient and rainfall intensity were established for interrill and rill erosion rate estimation in vegetation restoration areas. This study provides a theoretical basis for evaluating the soil and water conservation benefits of vegetation restoration and for improving soil erosion prediction models within the context of vegetation restoration.

Magnitude and hotspots of soil erosion types during heavy rainstorm events on the Loess Plateau: Implications for watershed management

In the context of climate change, rainstorm events are becoming increasingly frequent. In particular, on the Loess Plateau, heavy rainstorms are the primary cause of soil erosion. This study investigated and analysed different types of soil erosion hotspots and influencing factors in small watersheds under different rainstorm events in different areas of the Loess Plateau. The results indicate that the erosion intensities of rills, gullies, landslides and collapses ranged from 13600-46244, 1982-772201, 1163-172153 t km-2 and 1867-94985 t km-2, respectively. Newly constructed terraces exhibited an erosion intensity 1.6 times greater than that of old terraces, while terraces constructed before the rainy season in the current year exhibited an erosion damage intensity 2.6 times greater than that of terraces constructed after the rainy season in the previous year. In addition, under rainstorm conditions, landslides represented the most severe type of erosion in the watersheds, with the maximum amount of erosion accounting for more than 90 % of the total erosion amount, followed by gully or collapse erosion, with the collapse of terrace risers as the main contributor. Slope cultivation land, unpaved roads, terrace risers, and valley slopes below the gully shoulder line were identified as erosion hotspot areas. Rainstorm erosion was significantly influenced by the land use type and slope, which explained 14.2 %-41.5 % and 9.7 %-15.1 %, respectively, of the total variance in erosion intensity. We suggest that soil erosion prevention and control efforts on the Loess Plateau should focus on landslides on valley slopes below gully shoulder lines, followed by gullies on unpaved roads and the collapse of terraced fields. Drainage ditches and water cellars should be constructed above the gully shoulder line and on the inside of roads and terraces, thereby reducing erosion. Our research is crucial for optimizing and adjusting watershed management measures and preventing rainstorm erosion disasters.

Simulation and Spatio-Temporal Analysis of Soil Erosion in the Source Region of the Yellow River Using Machine Learning Method

The source region of the Yellow River (SRYR), known as the “Chinese Water Tower”, is currently grappling with severe soil erosion, which jeopardizes the sustainability of its alpine grasslands. Large-scale soil erosion monitoring poses a significant challenge, complicating global efforts to study soil erosion and land cover changes. Moreover, conventional methods for assessing soil erosion do not adequately address the variety of erosion types present in the SRYR. Given these challenges, the objectives of this study were to develop a suitable assessment and prediction model for soil erosion tailored to the SRYR’s needs. By leveraging soil erosion data measured by 137Cs from 521 locations and employing the random forest (RF) algorithm, a new soil erosion model was formulated. Key findings include that: (1) The RF soil erosion model significantly outperformed the revised universal soil loss equation (RUSLE) model and revised wind erosion equation (RWEQ) model, achieving an R2 of 0.52 and an RMSE of 5.88. (2) The RF model indicated that from 2001 to 2020, the SRYR experienced an average annual soil erosion modulus (SEM) of 19.32 t·ha−1·y−1 with an annual total erosion in the SRYR of 225.18 × 106 t·y−1. Spatial analysis revealed that 78.64% of the region suffered low erosion, with erosion intensity declining from northwest to southeast. (3) The annual SEM in the SRYR demonstrated a downward trend from 2001 to 2020, with 83.43% of the study area showing improvement. Based on these findings, measures for soil erosion prevention and control in the SRYR were proposed. Future studies should refine the temporal analysis to better understand the influence of extreme climate events on soil erosion, while leveraging high-resolution data to enhance model accuracy. Insights into the drivers of soil erosion in the SRYR will support more effective policy development.

Snow simulation for the rangeland hydrology and erosion model

In the western US, most rangelands receive snowfall. Yet, a commonly used tool to assess rangeland’s vulnerability to erosion, the USDA’s Rangeland Hydrology and Erosion Model (RHEM) is run using long-term simulated climate inputs that assumes that all precipitation occurs as rainfall. This can be problematic for areas that receive heavy snowfall or substantial rain-on-snow events. In this research, we have developed an efficient snow module for RHEM, called RHEM-Snow, which partitions precipitation between rainfall and snowfall, simulates snowpack accumulation and ablation, and passes net water input (consisting of rainfall, snowmelt, or both) to RHEM. In some areas, the inclusion of the snow module can reduce annual overland flow runoff and erosion estimates by more than 20 % of the total annual overland flow runoff and erosion produced without the snow module (or by as much as 10–50 mm/year for overland flow runoff or >100 kg/ha-yr for erosion). The reclassification of precipitation events from rainfall in RHEM to snowfall in RHEM-Snow tends to reduce overland flow runoff and erosion, but this reduction can be partially counterbalanced by increases from snowmelt and rain-on-snow. However, hydrologic responses to rain-on-snow events can either be enhanced or muted depending on the characteristics of the storm and the snowpack, as sometimes the snowpack can absorb the precipitation inputs, and sometimes snowmelt enhances the precipitation inputs. Because of this mixed impact, the average difference in erosion caused by rain on snow events is relatively small compared to corresponding events where only the liquid phase is considered. Further study is needed of the complex erosion processes under snowpack and frozen soil/variable saturation conditions. Overall, RHEM-Snow provides more realistic timing and magnitude of overland flow runoff and erosion in cold environments, better satisfying the conditions for RHEM applications.

CFD-DEM investigation of centrifugal slurry pump with polydisperse particle feeds

Polydisperse particle feed into centrifugal slurry complicates hydraulic performance and wall erosion but is poorly understood. This paper presents a numerical study of a centrifugal slurry pump, focusing on the effect of particle size distribution (PSD) using the combined computational fluid dynamics and discrete element method (CFD-DEM). It incorporates rigid impeller rotation and wall erosion. On this basis, the hydraulic and erosion model validity is verified by clear water performance and jet erosion test, respectively. Additionally, this CFD-DEM model is compared with the dense discrete phase model (DDPM), demonstrating more precise erosion prediction as its fully resolved particle-particle interactions. Generally, total pump erosion severity intensifies when the PSD is broadened. Compartment-wise, it indicates the necessity of tailoring flow structure to enlarge drag force, therefore, mitigate particle aggregation in the impeller. This in-house CFD-DEM model is promising for addressing particle-fluid flow problems in centrifugal pumps or coupling with data driven method.

Spatial assessment of soil resources on different land uses and slope gradient as a planning tool, in Ferenjua watershed, Ethiopia

Soil erosion, land degradation and climate change are the major environmental threats attributed to low agricultural productivity in Ethiopia. To reduce soil erosion and restore degraded lands, integrated soil and water conservation interventions have been implemented. However, the impacts of the intervention measures were not sufficiently studied due to the lack of baseline information. Therefore, this study was carried out to evaluate and understand the current conditions of biophysical resources in Ferenjua watershed, which is located in Gondar zuria district. In this study, more emphasis was given to the levels of total nitrogen (TN), available phosphorous (P), organic matter (OM), bulk density (BD), pH, moisture, texture and soil erosion. To collect the biophysical data, the watershed was divided into 144 grid-based sampling points with a resolution of 250 m by 250 m. In addition, the data were collected in 8 representative profile pits. Three primary land uses were identified from supervised land use and land cover classification and described as cultivated land (55.08 %), forestland (30.80 %), and grassland (14.12 %). Erosion hotspot map shows that >40 % of the watershed is moderately and highly susceptible to soil erosion. The highest BD (1.36 gm cm−3) was observed at Vertisols-dominated cultivated lands located in the flatlands, whereas, the lowest BD (1.28 gm cm−3) was observed under forestland. Regarding the results of TN, P, and OM, >60 % of the watershed was classified as having low to very low soil nutrient levels. Consequently, development interventions should be considered to restore degraded lands for the sustained use of resources in the watershed.

B2 and B3 glenoid osteoarthirtis: outcomes of corrective and concentric (C2) reaming of the glenoid combined with pyrocarbon hemiarthroplasty

Posterior humeral subluxation (PHS) in B2/B3 glenoid is a cause of asymmetric long-term stress on the glenoid and the potential reason for glenoid loosening in anatomic total shoulder arthroplasty (ATSA) and painful glenoid erosion in hemiarthroplasty with metallic heads (HA-Metal). We hypothesized that corrective and concentric reaming (CCR) of the glenoid associated with pyrocarbon hemiarthroplasty (HA-PYC) could improve the centering of the humeral head and decrease the risk of persistent painful glenoid erosion in young/active patients with B2/B3 glenoid. Between 2014 and 2020, 41shoulders (in 35 patients, mean age of 57.9 years) underwent HA-PYC combined with CCR reaming for B2 (n=30) or B3 (n=11) osteoarthritis. Patients were prospectively followed with computed tomography (CT) scans performed preoperatively, immediate postoperatively and at last follow-up (> 2 years). The primary outcomes were 3D-corrected CT-scan measurements of glenoid version, PHS, progression of glenoid erosion. Secondary outcomes included functional outcome scores, return to activities, and revision rate and complications. At a mean follow-up of 4.5 years (2 to 9.5 years), the prosthesis survival was 95% (39/41). No patient has been reoperated for painful glenoid erosion. The mean glenoid retroversion decreased from 17.1° ± 7.5 preoperatively to 8.3° ± 8.2 at last follow-up (p=0.001), and the mean PHS from 74% to 56.5% (p=0.001) based on the scapular plane and from 59.9% to 50.3% based on the glenoid plane. The humeral head was recentered in 97% according to the glenoid surface and 71% according to the scapular plane. Correction of PHS in the scapular plane was highly correlated to correction of glenoid retroversion (p<0.001). CT-scan measurements showed that the average total medialization was 3.7 ± 3.2 mm (2.0 ± 1.8 mm due to reaming and only 1.7 ± 2.4 mm due to erosion). The Adjusted Constant score increased from 43% ± 13 to 97% ± 16 and the Subjective Shoulder Value from 38% ± 14 to 84 % ± 12 (p<0.001). Overall, 84% of active patients returned to work and all patients returned to sports. In B2/B3 glenoid arthritis, corrective, concentric glenoid reaming combined with HA-PYC improves centering of the humeral head and shows a low risk of painful glenoid erosion at mid-term follow-up. The combined procedure results in excellent functional outcomes and high prosthesis survivorship at mid-term follow-up. HA-PYC and CCR is offering an alternative shoulder arthroplasty for young/active patients with B2/B3 glenoid osteoarthritis who want to return to work or sports practice.

Joint Damage and Low Lean Body Mass in a Cohort of Peruvian Patients With Rheumatoid Arthritis.

To determine the association between radiologic joint damage (JD) and a lower lean body mass (LBM) in rheumatoid arthritis (RA) patients. A cross-sectional study from a single center established RA cohort. JD and appendicular LBM (arms and legs) were measured with the Sharp/van der Heijde (SvdH) score and dual x-ray absorptiometry expressed as kg/m 2 , respectively. A univariable analysis was used to determine the association between JD an LBM; then, a multivariable regression model was performed to evaluate the persistence of this association, adjusted by age, gender, disease duration, socioeconomic status (by the Graffar method), tobacco use, anticitrullinated protein antibody levels, Disease Activity Score in 28 joints for RA with erythrocyte sedimentation rate, glucocorticoid use (as prednisone equivalent), disease-modifying antirheumatic drug use, body mass index, and disability (by the multidimensional Health Assessment Questionnaire). Two hundred forty-seven patients were included; the average (SD) age was 63.0 (12.8) years, disease duration 20 (15.00) years, the total SvdH was 66 (86.75), and the aLBM was 13.6 (3.82) kg/m 2 . In the univariable analysis, a lower appendicular LBM was associated with higher SvdH score on the female population, in terms of the total ( B = -8.6, p < 0.01), bone erosion (-4.4, p < 0.01), and joint space narrowing (-4.2, p < 0.01) scores; this correlation remained in the multivariable analysis in terms of total SvdH ( B = -9.5, p < 0.01), bone erosion (-5.2, p < 0.01), and joint space narrowing (-4.3, p < 0.01). A lower LBM in female patients was associated with more severe JD independently of other variables examined. Strategies aimed at preserving LBM could have a favorable impact on the course of disease.

Shoreline morphological change prognostic model based on spatiotemporal framework imagery data on the northern coast of Java, Indonesia

This study focuses on identifying the degree of shoreline changes on the north coast of Java Island (Indonesia), particularly the Batang Regency segment, using multiple data sources: Landsat 9 and 8, Landsat 5 TM, and PlanetScope spanning from 2000 to 2023. The degree of change was obtained by statistically calculating net shoreline movement (NSM), linear regression rate (LRR), and end-point rate (EPR) using the digital shoreline analysis system (DSAS) software. The three rate-of-change statistics were used to calculate the multidecadal shoreline change prediction or projection for the next 10 and 20 years using a Kalman filter-based model with a simple data assimilation technique. Based on these results, NSM indicated that the shoreline experienced a total accretion and erosion of 361.04 and 111.58 m, respectively, from 2000 to 2023. Over these years, the highest accretion rate reached 16.44 m/year (according to LRR) or 15.83 m/year (EPR), while the maximum erosion rate was up to 11.34 m/year (LRR) or 9.43 m/year (EPR). The use of two data sources with different spatial resolutions produces varying statistical values, which depend on the degree of detail and complexity of the data derived from the source imagery. The coastline prognosis model produced with the Kalman filter shows that the entire coastline in Batang Regency will most likely experience an average accretion and erosion of 18.03 and 21.42 m, respectively, in 10 years, while that in the next 20 years will be 26.38 and 33.3 m, respectively.

Comprehensive new insights on the potential use of SiC as plasma-facing materials in future fusion reactors

The performance of silicon carbide as an alternative plasma facing material (PFM) was studied at various irradiation conditions relevant to ion energies and fluxes of a fusion reactor. This analysis involves detailed modeling of subsurface plasma/material interactions, sputtered particle transport above the surface and redeposition, and related changes in material composition and microstructure induced by steady-state and Edge Localized Mode ion fluxes. Transition of a crystalline SiC surface to semi-crystalline and amorphous phases was analyzed based on advanced modeling of DIII-D tokamak experiments where SiC was irradiated in single- and multiple- L-mode and H-mode discharges. This analysis shows that displacement damage, particle deposition/redeposition, and D accumulation on the SiC divertor surface can lead to significant microstructural changes that result in enhanced sputtering erosion in comparison with the original crystalline material. However, the resulting total net erosion rate for a full-coverage, advanced tokamak, SiC coated divertor may well be acceptably low. Moreover, the C sputtering yield from the evolved SiC surface can be seven times lower than from a pure graphite surface; this would imply significantly reduced tritium co-deposition rates in a D-T tokamak reactor, compared with a pure carbon surface. It was also determined that chemical sputtering of both C and Si should not result in any noticeable effect on the net erosion, for attached plasma regimes. Our results thus show encouraging results overall for use of SiC as a PFM in tokamaks.

Assessing soil erosion through the implementation of the RUSLE model and geospatial technology in the Isser watershed, northern Algeria

ABSTRACT Soil erosion, triggered by rainfall and runoff, poses a significant challenge for Mediterranean countries, leading to sedimentation in dam reservoirs, decreased storage capacities, and reduced agricultural fertility. Among various erosion estimation models, the RUSLE equation stands out for its consistency and minimal data requirements. The present study aims to utilize geographic information systems (GIS) software to quantify and map soil loss in the Isser watershed in northern Algeria employing the RUSLE model to strategically plan development measures and prioritize actions to safeguard high-risk erosion areas. Implementing the RUSLE-GIS approach involves integrating multiple datasets, including precipitation, soil erodibility, topography, vegetation cover, and anti-erosion practices. By combining these factors, a comprehensive map depicting erosion rates is generated. The findings categorize potential soil erosion into six groups, ranging from very low to extremely high. They indicate that 61.5% of the Isser Basin faces erosion, varying from moderate to very high (&amp;gt;20 t ha−1 year−1). In addition, 25% of the total surface experiences erosion levels classified as high to very high (&amp;gt;50 t ha−1 year−1). This underscores the urgent need for anti-erosive measures. These measures aim to safeguard the basin's soils, extend the lifespan of existing dam reservoirs (Koudiet Acerdoune and Beni Amran), and preserve their water potential.

Analysis of Erosion and Sedimentation Rates on the Service Life of Telaga Lebur Dam

Dam is a civil construction structure in hydrology. The concept of a dam essentially provides a solution by serving as a water reserve, meaning that during the rainy season, water is collected in the dam reservoir, and during the dry season, the stored water can be used as needed. Dams are highly effective in addressing water scarcity issues, both for raw water supply and irrigation purposes. The purpose of building dams is to create a water supply system to supply water for village residents and for irrigation needs. Water availability in dry climate regions is generally limited. Climate change phenomena exacerbate water scarcity issues. As a precaution and mitigation measure against water scarcity, the Indonesian government is actively constructing dams across various provinces. Particularly in West Nusa Tenggara (NTB), a dry climate province facing challenges in water supply for households and irrigation, dam construction is essential. The level of total erosion hazard rate in the Telaga Lebur Dam Catchment Area is 5463.94 Ton/Ha/Year. 67.78% of the area of the Telaga Lebur Dam Catchment Area (11.23 km²) experiences erosion at a rate of 3703.5 Ton/Ha/Year, classified as very light erosion. 11.58% of the area of the Telaga Lebur Dam Catchment Area (25.90 km²) experiences erosion at a rate of 632.7 Ton/Ha/Year, classified as light erosion. 9.20% of the area of the Telaga Lebur Dam Catchment Area (20.58 km²) experiences erosion at a rate of 502.7 Ton/Ha/Year, classified as moderate erosion. 3.66% of the area of the Telaga Lebur Dam Catchment Area (8.19 km²) experiences erosion at a rate of 200 Ton/Ha/Year, classified as heavy erosion. 7.78% of the area of the Telaga Lebur Dam Catchment Area (17.41 km²) experiences erosion at a rate of 425.1 Ton/Ha/Year, classified as very heavy erosion. The total sediment yield in Telaga Lebur Dam is 16.619 m³/year. The reservoir's useful lifespan based on the analysis results is 11.44 years.

Half of the soil erosion in the Alps during the Holocene is explained by transient erosion crises as a consequence of rapid human land clearing

Human land use changes have altered soil erosion for millennia with extensive consequences on terrestrial and aquatic ecosystems as well as on biogeochemical cycles along the land-ocean continuum. Despite their great importance, past erosion trends have high uncertainties limiting quantitative estimates of long-term erosion dynamics. Here, we applied a new approach combining well-dated paleo-records of soil erosion from lake sediments and a spatially distributed semi-empirical model to simulate annual soil erosion in six lake watershed systems in the Northwestern Alps during the Holocene. Progressive and abrupt changes in soil erosion are detected in the six watersheds. Progressive erosion explains most of the soil exports observed during the Early to Mid-Holocene period (from 11,700 to 3000 cal. yr. BP), while transient erosion crises (i.e., periods of abrupt increase in the erosion rates spanning approximately 1000 ± 500 years) led to massive soil losses during the Late-Holocene period (from 3000 to 1000 cal. yr. BP). Our coupled approach of proxy-model reconstruction shows that the transient erosion crises represent the half of the total soil erosion exports during the Holocene. These estimates defy current representations of large-scale soil erosion during the Holocene that do not consider transient erosion crises, hence potentially underestimating the anthropogenic perturbation of lateral fluxes and fate along the land-ocean continuum. Our results further suggest that erosion and/or land cover proxies need to be consistently integrated into model approaches when attempting to estimate past variations in mass exports from terrestrial to aquatic ecosystems over centennial to millennial timescales.

Wind Speed and Vegetation Coverage in Turn Dominated Wind Erosion Change With Increasing Aridity in Africa

AbstractWind erosion is one of the main causes of land degradation and desertification. Clarifying the spatiotemporal variations of wind erosion and the dominant factors of its spatial characteristics and the temporal trend will contribute to the establishment of appropriate wind erosion control and management practices, which is essential for combating global land degradation and strengthening ecological protection in drylands. Here, we assessed wind erosion in Africa during 2001–2020 based on the Revised Wind Erosion Equation (RWEQ). We also analyzed the influential factor of spatial characteristics and temporal variation based on machine learning and other methods under different aridity. Results revealed that the average annual wind erosion modulus was 16,672 t/km2/a in Africa during 2001–2020, with hyper‐arid areas and arid areas accounting for more than 90% of the total wind erosion modulus. The spatial characteristics of wind erosion were dominated by natural factors but not anthropogenic activities. Except in hyper‐arid areas, wind speed and vegetation coverage together dominated the spatial characteristics. Wind speed was the dominant factor in wind erosion change, while in arid and semi‐arid areas, the capability of vegetation coverage to affect wind erosion change was comparable to wind speed. It can be concluded that, although revegetation does contribute to the reduction of wind erosion in arid and semi‐arid areas, taking into account water resource constraints and land use conflicts, large plantations can be replaced with windbreaks to increase vegetation coverage while reducing near‐surface wind speed, which improves the sustainability of ecological projects aimed at combating land degradation and desertification.

A study on soil aggregate stability and splash erosion under exogenous electrolyte conditions in the karst region of Southwest China

Study areaKarst region in Guangxi Province, Southwest China. Study focusBoth soil properties and rainfall characteristics have a critical influence on splash erosion and aggregate stability. However, the impact of electrolytes on splash erosion has received less attention. In this study, soils from 4 typical land use types (cropland, orchard, artificial forest and secondary forest) in karst region were utilized as the research objects. NaCl, KCl, and MgCl2 solutions of different concentrations were used to determine the stability of the aggregates via fast wetting (FW) treatment of Le Bissonnais (LB) method and the characteristics of splash erosion via simulated rainfall experiments. New hydrological insights for the regionResults revealed that both the land use types and electrolyte significantly influenced the soil aggregate stability and splash characteristics. Specifically, the change in land use from cropland to orchard, artificial forest and secondary forest significantly increased the aggregate stability, thus decreasing soil erodibility. The aggregate stability decreased and the total splash rate increased as the electrolyte concentration increased. The total splash erosion rate of the 4 soils was positively correlated with the <0.5 mm particle size released by aggregate fragmentation under simulated rainfall conditions. The results can provide a theoretical basis for soil erosion control and soil quality improvement in the karst region of Southwest China.

High rates of erosion on a wave‐exposed fringing coral reef

AbstractErosion is a key process in shaping the physical structure of coral reefs, yet due to erosion being semi‐cryptic and difficult to quantify, information remains limited. Here, we investigate erosional processes along Ningaloo Reef, an extensive fringing coral reef in Western Australia. We employed both direct and indirect methods to measure erosion in wave‐exposed reef slopes and protected lagoonal habitats. Direct measurements of erosion on coral blocks were among the highest found globally, with total erosion of 3.07 kg m−2 yr−1 (4% from micro, 0.6% from macro, and 94% from external), whilst indirect rates were estimated at 2.4 ± 0.20 kg m−2 yr−1 (78% from parrotfish, 22% from urchins). Indirect erosion rates were influenced by the species and size of parrotfish, with Chlorurus microrhinos removing 0.44 ± 0.19 kg m−2 yr−1 (22% of parrotfish erosion). Scanning electron microscopy and computed tomography show that micro and macroborer erosion contributions to direct erosion were low, most likely due to heavy grazing by parrotfish and the short deployment period of experimental substrates. A substantial portion of external erosion on blocks (0.53 ± 0.23 kg m−2 yr−1) could not be attributed to bioeroders and was poorly correlated with wave exposure, suggesting processes not quantified contribute to this unaccounted aspect of erosion. Our results confirm that bioerosion by parrotfish is especially significant at Ningaloo Reef, and large‐bodied individuals of C. microrhinos are key in conserving this key ecological process.