Calculation Of Erosion Rate Research Articles

Decadal-scale assessment of sediment denudation rates in the Zhoukou River Basin, Taiwan: insights from improved DEMs of differencing based on spectral analysis

This study assesses sediment erosion rates in the Zhoukou River Basin in southern Taiwan over the past three decades, focusing on the impact of extreme rainfall events. While various established methods determine erosion rates over different temporal scales, we employ an independent approach for decadal-scale erosion rate calculation by utilizing open-source global and regional digital elevation models (DEMs) data for two distinct periods. We introduce a new method that applies Fourier analysis to vertically register the DEMs, significantly minimizing their vertical bias. Through spectral analysis, we identify long wavelength topography crucial for correcting vertical offsets. Erosion rates, computed through DEMs of Difference (DoD), exhibit a similar trend of significant reduction in sediment export rates from 1990–2010 to 2011–2020 due to decreased extreme rainfall events, aligning with erosion rate estimates derived from mean suspended load data at gauge stations. Over the entire period from 1990 to 2020, the calculated denudation rate was 14.19 mm/yr, whereas in the recent decade (2011–2020), it decreased to 10.46 mm/yr. Our study suggests that the improved DoD method can effectively estimate sediment transport rates by leveraging underutilized DEMs captured at distinct points in time, especially when the erosional signal dominates data noise.

Methodology of data generation and calculation of erosion rates applied to littoral areas: Evolution of the Andalusian shoreline on exposed beaches during the 21st century (2001-2019)

This paper describes the methodology used for the data collection and calculation of erosion rates and presents the recent results for the period 2001-2019 for all the beaches of the Andalusian shoreline. This period is divided into two subperiods (2001-2011 and 2001-2019) to detect possible trend changes during the study years. The proxy corresponding to the internal limit of the backshore has been used, which is very useful for medium to long-term coastal erosion rates. The results show the rates calculated for this proxy, which reveal a high presence of artificially stabilised sectors where the inward migration of the shoreline associated with it is hindered, together with an intensification of the retreat rates in natural sections. Similarly, there is a clear differentiation between a relatively dynamic Atlantic façade with a higher percentage of erosive sectors and a Mediterranean façade highly conditioned by anthropic presence, with a lower percentage but a higher intensity in their values.

Numerical study on effect of operating condition and solid concentration on hydro-abrasive erosion of high head Francis turbine

The powerplants in the Himalayan region are generally subjected to hydro-abrasive erosion. The deterioration of components due to erosion causes reduction in performance, changes the fluid flow pattern and even the breakdown of the turbine. In the present work, the Bhilangana-III powerplant Francis turbine is considered a reference turbine for numerical investigation using the computational fluid dynamics (CFD) tool. The study presented an evaluation of hydro-abrasive erosion of high head Francis turbine for the different operating conditions and sediment concentrations. The modified Grant and Tabakoff erosion model is used for the erosion rate calculation. To investigate the effect of various operating conditions, the study is conducted at part load, best efficiency point (BEP) and high load. Also, to examine the impact of suspended sediment on the erosion of turbine components, the solid concentration varies from 500, 1200, 2000, 3000 and 4000 ppm. The observed erosion pattern is similar at all operating conditions for the stay vane, guide vane and runner, but the density of erosion is different. The observed deterioration density due to erosion is higher for part and full load than in the BEP condition. The guide vanes and runner vanes are highly susceptible to erosion due to higher absolute velocity and relative velocity at guide vane and runner vane, respectively. The observed erosion rate variation is qualitatively in-line with the on-field turbine erosion condition. It is also found that the increase in erosion rate with the sediment concentration is almost linear but more than 90% and 79% higher for the runner than stay vane and guide vane, respectively.

Long-term assessment of terrain changes and calculation of erosion rates in an alpine catchment based on SfM-MVS processing of historical aerial images. How camera information and processing strategy affect quantitative analysis

Long-term assessment of terrain changes and calculation of erosion rates in an alpine catchment based on SfM-MVS processing of historical aerial images. How camera information and processing strategy affect quantitative analysis

Recreationally created footpaths as a means of preserving specific biotopes of bare sand accumulations: Evidence provided by dendrogeomorphic reconstruction

The combination of accumulation and erosion processes is the dominant geomorphic agent forming the surface of bare sand accumulations. These unique biotopes are gradually vanishing; thus, knowledge of their past dynamics is of crucial interest. This study focused on a selected locality with bare sand in the Borská Lowland (Slovakia). In total, nine buried individuals of Pinus sylvestris (L.) were used for the reconstruction of the accumulation rate of sand, and 13 exposed roots of the same tree species served as the data source for the erosion rate calculation. Detailed analysis of growth responses in trees and roots provided evidence about macroscopic and microscopic growth responses that are usable even in other studies and suggested P. sylvestris as a sensitive species for the reconstruction of accumulation and erosion processes. Reconstructed values of mean accumulation rate were higher than the mean erosion values. Finally, the obtained results were put into an anthropogenic context because the studied locality is surrounded by zones with seasonally inhabited holiday cottages. The effect of anthropogenic activities (particularly by stepping) can be associated with the wide spectrum of collected evidence: Bare sand areas were not located around other water reservoirs with the absence of recreational activities in the region. The erosion zone in the studied locality follows the zone with an increased number of forest pathways. It is possible that the increased nutrition content in transported sand due to gardening affected the occurrence of growth releases in the studied trees.

Meteoric 10Be, 137Cs and 239+240Pu as Tracers of Long- and Medium-Term Soil Erosion—A Review

Isotopes of meteoric 10Be, 137Cs, 239+240Pu have been proposed as a soil redistribution tracer and applied worldwide as an alternative method to classical field-related techniques (e.g., sediment traps). Meteoric 10Be provides information about long-term soil redistribution rates (millennia), while 137Cs and 239+240Pu give medium-term rates (decades). A significant progress in developing new models and approaches for the calculation of erosion rates has been made; thus, we provide a global review (n = 59) of research articles to present these three isotopes (meteoric 10Be, 239+240Pu and 137Cs) as soil erosion markers in different environments and under different land-use types. Understanding the dynamics and behaviours of isotopes in the soil environment is crucial to determine their usefulness as soil erosion tracers; thus, we discuss the chemical–physical behaviour of meteoric 10Be, 137Cs and 239+240Pu in soils. The application of these isotopes sometimes has strong limitations, and we give suggestions on how to overcome them or how to adapt them to a given situation. This review also shows where these isotopic methods can potentially be applied in the future. A lack in knowledge about soil redistribution rates exists particularly in loess-dominated areas where the tillage system has changed or in areas with strong wind erosion.

The effect of dem resolution on calculation of erosion in Batang Kuranji watershed

Batang Kuranji Watershed with a total area of Watershed 224.7 km2 comprises Batang Sungai Sapiah Sub-watershed, Batang Danau Limau Manih Sub-watershed, Batang Sungkai Sub-watershed, Batang Bukik Tindawan Sub-watershed and Batang Padang Janiah Sub-watershed. Batang Kuranji flows from upstream of the Bukit Barisan with the highest elevation of 1,605 meters above sea level at the peak of Bukit Tinjau Laut and empties into the Padang beach with a main river length of ± 32.41 km. DEM has an influence on the results of land erosion by affecting the slope accuracy. The higher the DEM resolution, the more precise the results of the soil erosion simulation. With the MUSLE method the rate of erosion occurs in the Batang Kuranji watershed, with DEM data of 8m and land cover in 2017, an erosion rate of 23.91 tons / hectare / year is classified in hazard class II (light), DEM data of 30m erosion rate is 7. 70 tons / hectare / year are classified in hazard class I (very mild), with DEM data of 90m erosion rate of 4.54 tons / hectare / year classified in hazard I class (very light). It can be seen that the higher the DEM resolution, the more accurate the erosion rate calculation in the watershed.

Uplift Quantification and Erosion Rate Estimation in Northwestern Tunisia from Topographic and Lithologic Data

Digital elevation modeling (DEM) was used to determine key morphological features such as hypsometry, slopes and topographic evolution in correlation with tectonic regimes and erosion mechanisms. This contribution discusses the tectonic model of northern Tunisia, which since 1977 has been described by geologists as an allochthonous unity domain of the Serravallian-Tortonian. This study presents new data from the erosion rate calculation following the establishment of these units and then proposes another view on regional tectonics. Therefore, the example used of Oued Sedjnene gives a rising rate of the order of 0.01 mm/year, almost equivalent to the results found in surrounding medeterranean belt (ex. Italy and Turkey). The structure and geomorphology of northern Tunisia is a result of folding of Cenozoic basin. However located tangential structure are related to transcurrent faults and not overthrust structure.

Prediksi Laju Erosi dan Valuasi Ekonomi pada Area Reklamasi Pertambangan Batu Bara

Mining activities had positive and negative impacts on the environment. Erosion is one of the negative impacts that must be managed. This research carried out due to the problem of different predicted erosion and the actual condition in one of the reclamation areas of PT X. This research aims to analyze the erosion rate and economic value on the mining reclamation activities of PT X. This research method carried out using the calculation of erosion rates with USLE, the Erosion Hazard Index (IBE), interviews with village communities around PT X and calculated economic value due to erosion with an economic valuation using Total Economic Value (NET). The results indicate that the calculation of erosion rates with the USLE approach of 35,351.69 tons/ha/year and the value of the Erosion Hazard Index (IBE) with the Very High category dominating reclamation area with a percentage of 61,11%. The results of the economic valuation calculation are Rp13,7 billion/year, and the recommended erosion management is to manage factors C and P to reduce the rate of erosion.

Reference Inventory of 210Pb in Soils of Chinese Mainland

Naturally occurring fallout 210Pb is strongly adsorbed by soils and has been widely used as a tracer to soil erosion and deposited sediments in various sedimentary environments. The determination of reference inventory is the premise and basis of soil erosion research using this technique,it is directly related to the accuracy of erosion rate calculation. This paper starting reports from the selection of 210Pb reference inventory sampling points, the distribution of 210Pb reference inventory in Chinese mainland is summarized. It is pointed out that the reference inventory is mainly affected by the location of land and sea, climate, topography and other factors.

Glacial influence on late Pleistocene 10Be-derived paleo-erosion rates in the north-western Himalaya, India

Terrestrial cosmogenic nuclide concentrations in fluvial deposits allow estimation of paleo-erosion rates and reconstruction of the response of landscapes to climatic perturbations. In partly ice-covered landscapes, however, incorporation of subglacially-derived sediments that were shielded by ice from cosmic can lead to erroneous erosion rate calculations. Here, we combine in situ-produced 10Be-derived erosion rates, based on sand and pebbles from a fluvial fill terrace and the modern riverbed in the upper Yamuna catchment, with numerical ice flow modelling to quantify this bias. New luminescence and surface exposure ages suggest that aggradation of the exposed deposits occurred between 29.9 ± 2.5 ka and 14.8 ± 2.8 ka. During most of the deposition, glaciers probably covered ∼19% of the catchment. 10Be concentrations of terrace sand samples differ from those of pebble samples. We obtained the lowest erosion rates from quartzite pebbles, which stem from low elevations, and the highest erosion rates from crystalline pebbles, which stem from high elevations in the Yamuna catchment. We explain these different erosion rates by differences in the steepness of the source areas, an effect that prevails throughout the entire aggradation period despite significant former ice-cover. Sand samples, which are thought to be derived from all elevation parts of the catchment, however show lower 10Be concentrations during the aggradation compared to present-day. We argue that this difference is due to a substantial subglacial origin of the sand during the aggradation period, and not necessarily related to enhanced erosion. We conclude that aggradation of the valley fill in the Yamuna catchment is most likely due to reduced discharge, and only marginally related to higher erosion rates during the late Pleistocene.

Effect of DEM Resolution on Erosion in Batang Kuranji Watershed

Batang Kuranji Watershed is one of the region river at Indragiri - Akuaman with a total area of Watershed 224.7 km2 consisting of Batang Sungai Sapiah Sub Watershed, Batang Danau Limau Manih Sub Watershed, Batang Sungkai Sub Watershed, Batang Bukik Tindawan Sub Watershed and Batang Padang Janiah Sub Watershed. Batang Kuranji flows from upstream of the Bukit Barisan with the highest elevation + 1,605 meters above sea level at the peak of Bukit Tinjau Laut and empties into the Padang beach with a main river length of ± 32.41. DEM has an influence on the results of land erosion by affecting the slope accuracy. The higher the DEM resolution, the more precise the results of the soil erosion simulation. With the Musle method the rate of erosion occurs in the Batang Kuranji watershed, with DEM data of 8m and land cover in 2017, an erosion rate of 23.91 tons / ha / year is classified in hazard class II (light), DEM data of 30m erosion rate is 7. 70 tons / ha / year are classified in hazard class I (very mild), with DEM data of 90m erosion rate of 4.54 tons / ha / year classified in hazard I class (very light). It can be seen that the higher the DEM resolution, the more accurate the erosion rate calculation in the watershed.

Erosion Due to Solid Particle Impact on the Turbine Blade: Experiment and Simulation

Erosion of components working in particulate environment is a serious problem that causes premature failure. In this study, we want to identify different areas caused by particle impact erosion and also express a permanent impression using experimental method. Our study was performed on the real turbine blade worked in the industry. This paper investigated the effect of particle velocity and particle diameter on erosion rate of a smooth surface using FE method. Criterion of erosion rate calculation is sum of the all elements with strain of more than 0.2%. Particle velocity and particle diameter were considered in the range of 100–500 m/s and 1–5 mm, respectively.

Study and analysis of the cavitating and non-cavitating jets - Part one: Parameters controlling force, power and the jet behavior

This paper presents the dependency of the jet power and the cavitation intensity on the working conditions of the cavitating and non-cavitating jet flow. This dependency is indicated by the cavitation erosion process and flow structure. The effects of working conditions on the cavitation erosion were experimentally investigated. The flow visualization was done using a high-speed photography recording system. The analysis shows that the erosion rate calculation and the visualization of the jet structure can be used as tools to estimate the jet strength, the jet actions, the jet power, and the performance of the jetting system.

Geospatial-Interface Water Erosion Prediction Project (GeoWEPP) application for the planning of Bompon Watershed conservation-prioritized area, Magelang, Central Java, Indonesia

Bompon watershed is located in the Quaternary Volcano (Mt. Sumbing) and tertiary (Mt. Menoreh) transition zones. The implication is that the soil material is well developed with super thick characteristic and is sensitive to erosion. The existence of land processing interventions by the locals supports the increasingly high rate of erosion. The use of the GeoWEPP model facilitates the rapid calculation of erosion rates and evaluation of conservation applications. The aim of the study was to calculate the erosion rate and determine the priority areas with the GeoWEPP erosion model. The GeoWEPP application was chosen because of its ability to show the spatial distribution of erosion and sedimentation. Evaluation of prioritized areas is carried out with the erosion rate criteria of the model and the important value of the land. The results of the Bompon watershed erosion model show variations in erosion and sedimentation. High erosion is in hilly morphology (slope of > 25%) with agricultural land annual crops (moor) and mixed gardens. High sedimentation is on the colluvial plains with moorland and rice fields land use. The existence of agricultural areas with cassava, corn and rice commodities has important value for villagers. Agriculture is the main livelihood of the community so that it has priority in handling conservation to maintain the productivity of the agricultural land. The assessment criteria for rate erosion and important value of the land produce priority sub-watershed that location covering 2 locations with an erosion rate of 441 tons/ha and 438.2 tons/ha.

Prediction of sand erosion in CFD with dynamically deforming pipe geometry and implementing proper treatment of turbulence dispersion in particle tracking

Predicting more accurate sand erosion rate in oil and gas production is important for maintaining safe and reliable operations while maximizing output efficiency. Computational fluid dynamic (CFD) is a powerful tool for erosion prediction and provides detailed erosion pattern in complex geometry. To improve accuracy of erosion prediction, first part of this paper proposes an algorithm to include the effect of dynamically changing pipe geometry in CFD based erosion modelling and second part of this paper provides guidelines for proper treatment of turbulence dispersion in CFD based erosion modelling.Sand erosion is a time-dependent phenomenon where most severe erosion scars are localized and occurs under disturbed flow conditions. These localized high erosion rates cause substantial change in pipe geometry, creating cavities which modify the flow field, the particle trajectories and eventually the erosion pattern. This work has illustrated that the erosion prediction can be influenced by including the effect of dynamically changing pipe geometry in CFD modelling. An algorithm was developed to couple erosion rate calculations with a Moving-Deforming-Mesh, which dynamically deforms the solid wall surface geometry and computational mesh based on the local erosion rate at regular time intervals. This effect will be significant for geometries involving sharp corners and/or regions of recirculation zones.Sand erosion largely depends on particle impact location, impact angle and impact velocity - which is the commutative effect of particle trajectory leading to the bounding surface. The particle trajectory is determined based on mean and the turbulence of the flow field. In steady state CFD simulations with Reynolds Averaged Naiver Stokes (RANS) turbulence models, turbulent dispersion is obtained from mean turbulence quantities using a stochastic random walk model, which estimates the instantaneous characteristics of a turbulent eddy. However, stochastic random walk model parameters will have significant effects on turbulence dispersion of the particles and hence the erosion prediction. Specific guidelines for these model parameters can improve the accuracy and consistency in CFD based erosion prediction.

Numerical Study of Sediment Erosion Analysis in Francis Turbine

Effective hydraulic turbine design prevents sediment and cavitation erosion from impacting the performance and reliability of the machine. Using computational fluid dynamics (CFD) techniques, this study investigated the performance characteristics of sediment and cavitation erosion on a hydraulic Francis turbine by ANSYS-CFX software. For the erosion rate calculation, the particle trajectory Tabakoff–Grant erosion model was used. To predict the cavitation characteristics, the study’s source term for interphase mass transfer was the Rayleigh–Plesset cavitation model. The experimental data acquired by this study were used to validate the existing evaluations of the Francis turbine. Hydraulic results revealed that the maximum difference was only 0.958% compared with the CFD data, and 0.547% compared with the experiment (Korea Institute of Machinery and Materials (KIMM)). The turbine blade region was affected by the erosion rate at the trailing edge because of their high velocity. Furthermore, in the cavitation–erosion simulation, it was observed that abrasion propagation began from the pressure side of the leading edge and continued along to the trailing edge of the runner. Additionally, as sediment flow rates grew within the area of the attached cavitation, they increased from the trailing edge at the suction side, and efficiency was reduced. Cavitation–sand erosion results then revealed a higher erosion rate than of those of the sand erosion condition.

Contribution of climate and land cover changes to reduction in soil erosion rates within small cultivated catchments in the eastern part of the Russian Plain during the last 60 years

The eastern part of the Russian Plain is an important agricultural region of European Russia with high proportion of cultivated lands in the steppe, forest-steppe and forest (southern part) landscape zones. Soil erosion is the main process of land degradation and surface water contamination there. Climate and land cover changes have been observed in this region during the last 30 years. However, field quantitative assessments of soil erosion rates are not available for the eastern part of European Russia due to the lack of monitoring data as well as the evaluation of erosion/deposition processes in cultivated catchments using other field methods. Three representative small cultivated catchments with high (> 80%) proportion of cultivated lands were selected in the forest (southern part), forest-steppe and steppe zones of the study region to evaluate sedimentation rates in dry valley bottoms of the catchments for two-time intervals (1963–1986 and 1987–2016) based on the application of the bomb-derived and Chernobyl-derived 137Cs isotope for sediment dating. The 3–4 depth 137Cs profiles were used to assess the sedimentation rates within the each investigated catchment. It was established that the sedimentation rates have considerably decreased (at least 2–3 times) over the last 30 years compared to 1963–1986 in all the investigated catchments. This is in agreement with results of erosion rate calculations using erosion models for the forest zone, however not consistent with erosion rates assessments for the forest-steppe and steppe zones. According to the model calculations, erosion rates show a slight decrease in the forest-steppe zone and increase in the steppe zone. The reduction in surface runoff during snowmelt period is one of the reasons for decrease in erosion rates within cultivated slopes for all the investigated catchments. The increase in proportion of perennial grasses in the regional crop rotation is another important reason for the decrease in erosion rates for the catchment located in the south of the forest zone. The importance of land cover changes in a major decrease of soil losses from the cultivated fields of the investigated catchments located in the forest-steppe and steppe zones cannot be identified due to the lack detailed information about crop rotation for those particular sites. However, available regional information about crop rotation changes for the two-time intervals (1960–1980 and 1996–2012) do not explain very high reduction in sedimentation rates in the dry valley bottoms after 1986.

Uncertainty quantification in erosion predictions using data mining methods

The transport of solids in multiphase flows is common practice in energy industries due to the unavoidable extraction of solids from oil and gas bearing reservoirs. The persistent collision of solids to the pipeline can lead to erosion, i.e., the removal of internal surface of the pipeline. Reliable estimates of erosion rates are essential for designing and safely operating pipelines that transport solids. Prediction of erosion rates in multiphase flow is a complex problem due to the lack of accurate models for predicting particle movements in the flow and their impact velocities to the wall. The erosion-rate calculations also depend on the accuracy of the flow regime predictions in the pipeline. The comparisons of existing model predictions to experimental data revealed that the predictions might differ by several orders of magnitude for some operating conditions. The goal of this paper is to introduce a computational framework that estimates the model-prediction uncertainty of erosion-rate models. The inputs are a model predicting erosion rates and a database containing erosion-rate measurements at various operating conditions. The framework utilizes a non-parametric regression analysis, Gaussian Process Modeling (GPM), for estimating the model-prediction uncertainty. We compare two approaches for clustering the data prior to training GPMs: (1) a flow regime based clustering, and (2) a new clustering approach introduced in this paper. The results reveal that the new data clustering approach significantly shrinks the confidence intervals of the uncertainty estimates.

The Effect of Grain Refinement on Solid Particle Erosion of Grade 5 Ti Alloy

In this work, the results on solid particle erosion of an ultrafine-grained Grade 5 titanium alloy, which was produced using high-pressure torsion (HPT) technique, are presented. In order to assess influence of the HPT treatment on material’s behavior in erosive conditions, special experimental procedures were developed. The ultrafine-grained (UFG) alloy was tested alongside with a conventional coarse-grained (CG) Grade 5 titanium alloy in equal conditions. The experiments were conducted in a small-scale wind tunnel with corundum particles as an abrasive material. Both particle dimensions and particle velocities were varied in course of the experiments. Erosion resistance of the samples was evaluated in two ways—mass reduction measurements with subsequent gravimetric erosion rate calculations and investigation of samples’ surface roughness after erosion tests. The UFG titanium alloy demonstrated considerable improvement of static mechanical properties (ultimate tensile strength, microhardness), whereas its CG counterpart appeared to be slightly more resistant to solid particle erosion, which might indicate the drop of dynamic strength properties for the HPT-processed material.