Erosion Studies Research Articles

Coastal Erosion Identification and Monitoring in the Patras Gulf (Greece) Using Multi-Discipline Approaches

The primary objective of this research is to demonstrate advanced surveying methods and techniques for coastal erosion identification and monitoring in a densely human-populated coastline, the southern coastline of the Gulf of Patras (Greece), which diachronically suffers erosion problems expected to become worse in the forthcoming years due to climate change and human intervention. Its importance lies in the fact that it presents a robust methodology on how all modern scientific knowledge and techniques should be used in coastal erosion problems. The presented methods include the use of satellite and aerial photo imaging, shallow seabed bathymetry and morphology, sediment sampling, geotechnical investigations, as well as hydrodynamic modelling. The results are extensively analyzed in terms of their importance in coastal erosion studies and are cross-validated to define those areas most vulnerable to erosion. Towards this scope, the seabed erosion rate produced by hydrodynamic modelling is compared with the coastal vulnerability index (CVI) calculations performed in the examined area to identify which coastal zones are under a regime of intensive erosion. The results between the CVI and the seabed erosion rate appear to coincide in terms of the erosion potential, especially in zones where the vulnerability regime has been calculated as being high or very high, with the P. oceanica meadows playing an important role in reducing erosion.

MORPHOLOGY AND SPUTTERING OF TUNGSTEN NITRIDES COATINGS EXPOSED TO DEUTERIUM PLASMA

Processes of sputtering, surface modification and change in the stoichiometric composition of W and WN coatings deposited on stainless steel by cathodic arc evaporation were studied under the influence of low-energy (500 eV/D) deuterium plasma with fluence of (1…4.5)1024 D2 +/m2 at room temperature. The composition of the WN coating changes under the influence of deuterium plasma, its enrichment with tungsten up to 100 % is observed. Results of erosion studies indicated that the sputtering yields for coatings WN and W are ~ 2.410-2 at./ion and to be systematically higher than the published data which were measured for bulk materials.

Numerical study of erosion in dense gas–solid flow in new generation cyclones using two-way and four-way coupling

Numerical study of erosion in dense gas–solid flow in new generation cyclones using two-way and four-way coupling

Measuring Annual Sedimentation through High Accuracy UAV-Photogrammetry Data and Comparison with RUSLE and PESERA Erosion Models

Model-based soil erosion studies have increased in number, given the availability of geodata and the recent technological advances. However, their accuracy remains rather questionable since the scarcity of field records hinders the validation of simulated values. In this context, this study aims to present a method for measuring sediment deposition at a typical Mediterranean catchment (870 ha) in Greece through high spatial resolution field measurements acquired by an Unmanned Aerial Vehicle (UAV) survey. Three-dimensional modeling is considered to be an emerging technique for surface change detection. The UAV-derived point cloud comparison, applying the Structure-from-Motion (SfM) technique at the Platana sediment retention dam test site, quantified annual topsoil change in cm-scale accuracy (0.02–0.03 m), delivering mean sediment yield of 1620 m3 ± 180 m3 or 6.05 t ha−1yr−1 and 3500 m3 ± 194 m3 or 13 t ha−1yr−1 for the 2020–2021 and 2021–2022 estimation. Moreover, the widely applied PESERA and RUSLE models estimated the 2020–2021 mean sediment yield at 1.12 t ha−1yr−1 and 3.51 t ha−1yr−1, respectively, while an increase was evident during the 2021–2022 simulation (2.49 t ha−1yr−1 and 3.56 t ha−1yr−1, respectively). Both applications appear to underestimate the net soil loss rate, with RUSLE being closer to the measured results. The difference is mostly attributed to the model’s limitation to simulate gully erosion or to a C-factor misinterpretation. To the authors’ better knowledge, this study is among the few UAV applications employed to acquire high-accuracy soil loss measurements. The results proved extremely useful in our attempt to measure sediment yield at the cm scale through UAV-SfM and decipher the regional soil erosion and sediment transport pattern, also offering a direct assessment of the retention dams’ life expectancy.

Importance of Fiber-/Nanofiller-Based Polymer Composites in Mechanical and Erosion Performance: A Review

The addition of nanofillers in the polymer matrix composites (PMC) has shown a considerable improvement in the mechanical properties and acts as a suitable replacement material. Among the various properties, erosion studies play a key role in the establishment of new materials in engineering applications irrespective of material properties. This paper primarily focus on mechanical properties of PMC and provides a view of the erosion studies conducted on various PMC that are reinforced with natural fibers and nanofillers. The study related to natural fiber as secondary reinforcement and nanofiller as primary reinforcement is taken into consideration. The natural fibers such as sisal-, pineapple-, jute-, bamboo-, banana-based polymer composites and their improvement in mechanical properties by the addition of various fillers are compared and reported. From the survey, it was noticed that the incorporation of nanofillers with natural fiber and polymers provides an acceptable range of material behavior. Being the natural fiber and its proper surface treatment enhance erosion resistance behavior.

Soil Erosion in the Central Russian Upland: A Review

This literature review analyzed more than 100 publications on soil erosion in the Central Russian Upland, one of the most erosion-prone regions of Russia. The selection of scientific papers was carried out from open web resources, domestic and international citation databases. The following parameters have been analyzed: time; geographical position; scale and methods of research; soil and geomorphological features; anti-erosion measures; type of erosion and rates of soil washout/accumulation; bibliographic information about the publication. There is a shortage of studies at the small-scale and medium-scale levels. The confinement of large-scale studies to the main watershed of the Central Russian Upland was revealed. There are discrepancies in the estimates of soil erosion by different authors, especially at different scale levels. An analysis of changes in soil erosion over time indicates a decrease in the rate of soil erosion in general on the Central Russian Upland, mainly due to climate change and a reduction in the area of arable lands. A lack of studies of rainfall, mechanical and wind erosion of soils in this area has been revealed.

Experimental Study of External Pipe Wall Erosion due to Water Pipe Leakage

Burst pipes can cause severe pressure drops and water pollution in water distribution networks. Small leaks can develop into pipe bursts over time due to interactions between pipes, water, and soil. This paper presents preliminary experimental results on the erosion of the outer wall of a pipe by solid particles when a leak occurs in a pressurized pipe and causes soil fluidization. A series of experiments were carried out with 50-mm-diameter and 3-mm-wall-thickness polyethylene (PE) pipes with various leak holes buried in silica sand bedding. The experiments investigated the effects of the leak size, shape, and direction on the erosion process. The findings indicated that the size of the leaks had the greatest impact on erosion rate, and erosion rate was nearly completely unaffected by the geometry of the leak hole or leak orientation.

Numerical study of erosion and deposition of sandy beach in presence of breakwater with spill hole

This paper presents a numerical study on erosion and deposition of a sandy beach installed with a breakwater bearing spill holes, aiming to understand its performance in erosion reduction. The two-dimensional (2D) governing equations for the water-sand mixture are solved by the VOF method and other techniques. The numerical approaches are validated against experimental data for wave propagation on an impermeable beach with a breakwater, scour underneath a pipeline, scour in front of a breakwater, and erosion and deposition of a sandy beach. On these bases, numerical simulations are made for three scenarios: a sandy beach, a sandy beach with a breakwater, and a sandy beach with a breakwater with spill holes. Then, the study proceeds to a detailed investigation of the third scenario with different breakwater locations, spill hole sizes, water depths, and wave heights. The results indicate that the breakwater indeed reduces beach erosion, and the breakwater location and wave height have a pronounced influence on the erosion. The breakwater's performance in reducing beach erosion achieves a maximum at a specific size of the hole opening. It is anticipated that the understanding revealed in this study sheds light on the design and application of breakwaters.

Applying Convolutional Neural Network to Predict Soil Erosion: A Case Study of Coastal Areas.

The development of ecological restoration projects is unsatisfactory, and soil erosion is still a problem in ecologically restored areas. Traditional soil erosion studies are mostly based on satellite remote sensing data and traditional soil erosion models, which cannot accurately characterize the soil erosion conditions in ecological restoration areas (mainly plantation forests). This paper uses high-resolution unmanned aerial vehicle (UAV) images as the base data, which could improve the accuracy of the study. Considering that traditional soil erosion models cannot accurately express the complex relationships between erosion factors, this paper applies convolutional neural network (CNN) models to identify the soil erosion intensity in ecological restoration areas, which can solve the problem of nonlinear mapping of soil erosion. In this study area, compared with the traditional method, the accuracy of soil erosion identification by applying the CNN model improved by 25.57%, which is better than baseline methods. In addition, based on research results, this paper analyses the relationship between land use type, vegetation cover, and slope and soil erosion. This study makes five recommendations for the prevention and control of soil erosion in the ecological restoration area, which provides a scientific basis and decision reference for subsequent ecological restoration decisions.

Useing of Remote SensingTtechnologies in Assessing Degradation of Soil and Vegetation Cover West Fold Makhoul

This study aimed to assess the state of deterioration (Degradation Status) to different sites of the soil, depending on the possibility of the use of remote sensing as one of modern technologies, and effective monitoring and control of the changes that you get the natural resources of soil degradation and vegetation operations as well as the risk of wind erosion study was conducted in the province Salah al-Din in an area between the city of Baiji, Sharqat south and the north, which represents the western flank of the fold Makhoul total area amounted to 402.20 km2. And was able to study with the help of technologies for remote sensing of determining the status and degree of deterioration of the soils study, which varied between moderate deterioration region, and severe deterioration, very severe degradation. The study confirmed that there is a decline in soils degraded area deteriorated moderate and actress soils untapped cultivation of grain crops increased by 33.64% of the study area space while soils degraded area recorded a severely degraded and actress soils affected by salts untapped increase of 24.55% of the area of ​​the region, while the soils degraded area deteriorated very strong and actress soils affected by salts untapped fragile dunes was registered an increase of about 9.08% of the study area, depending on the area of ​​the space visuals captured for the years 1976 and 2014 .

Axial-Flow Pump with Enhanced Cavitation Erosion Resistance

Axial-flow pumps, in addition to providing high anti-cavitation properties, must have high anti-erosion properties to ensure the required lifetime of the pump. Erosion damage of surfaces occurs when the net positive suction head (NPSH) significantly exceeds its critical value. The object of the study in this article is the axial-flow pump with a specific speed of 600 in two alternatives: № 1 and № 2. By analysis of the flow in the impeller blade systems, the ratio value between the NPSH, which ensures the absence of erosion, and the NPSH3, at which pump operational failure occurs, was determined. Impeller variant № 1 did not provide the required ratio. Impeller variant № 2 had higher cavitation qualities, and the required ratio was achieved for it. Energy, cavitation, and erosion characteristics of the axial-flow pump with impeller № 2 in rotational frequency n = 2000 rpm were investigated. Easily breakable paint coatings were used for the accelerated study of cavitation erosion. The experiment was carried out at three different flow rates and confirmed the assumptions made—the pump with impeller № 2 was not affected by cavitation erosion at the optimum flow rate. Patterns of erosion zones were accompanied by calculations of vapor zones in the impeller. At flow rates less than the optimum, cavitation disruptions occurred and appeared behind the vapor region. As a result, the condition of ensuring erosion-free flow in the impeller of an axial pump with a specific speed of 600 was obtained, ensuring the ratio NPSH/NPSH3 > 2.5. Recommendations on designing of erosion-free flow part of the axial pump impeller were also obtained.

Correction factor for determining mean velocity of shallow flow on rough surfaces under varying inundation conditions using dye tracer method

AbstractAccurate estimation of mean flow velocity is crucial for hydraulics and soil erosion studies. A correction factor (α) is required to convert flow surface velocity to mean velocity when using the dye tracer method. However, the determination of an appropriate α value is challenging and little information is available about how α varies with progressive inundation conditions, especially for rough surfaces with protruding roughness elements (e.g., stones). Therefore, laboratory experiments were conducted in a flume with sandpaper (SD) and stones (ST) surfaces to investigate the impact of roughness elements on the correction factor with varying inundation conditions. The results showed that using a single α value is inappropriate for rough surfaces. The correction factor was positively correlated with the Reynolds number and is controlled by flow regimes as well. Moreover, the impacts of inundation conditions as well as protruding roughness elements should be taken into account for determining α. Correction factor varied non‐monotonically with inundation ratio, depending on the progressive inundation status of protruding roughness elements. The developed equations introducing the inundation ratio performed well in predicting α, with R2 = 0.86 and NSE = 0.91. The results contribute to our understanding of measuring mean flow velocity using the dye tracer method.

Predicting Soil Erosion Rate at Transboundary Sub-Watersheds in Ali Al-Gharbi, Southern Iraq, Using RUSLE-Based GIS Model

The empirical soil loss model, RUSLE, was used in conjunction with remotely sensed data and geographic information system technology to delineate the soil erosion and watershed priorities in terms of conservation practices at seven boundary sub-watersheds (labeled as SW-00, SW-01, …, SW-06) between Iraq and Iran in the district of Ali Al-Gharbi, southern Iraq. The six factors of the RUSLE model, i.e., the rainfall erosivity, the soil erodibility, the slope steepness length, the crop management, and management practice, were calculated or estimated using information from different data sources such as remotely sensed data and previous studies. The results revealed that the annual soil erosion loss ranges from 0 to 1890 (tons h−1 y−1) with an average of 0.66 (tons h−1 y−1). Values of soil erosion were classified into five classes: very low, low, moderate, high, and very high. The potential soil loss in the high and very high classes ranges from 14.84 to 1890 (tons h−1 y−1), and these classes occupy only 27 km2 of the study area, indicating that the soil loss is very low in the area being examined. In terms of the spatial distribution of soil loss, the northern and northeastern parts (mountains and hills) of the sub-watersheds where the slope is steeper are more likely to erode than the plain area in the southern and southeastern portions, indicating that slope, in addition to rainfall erosivity, has a dominant effect on the soil erosion rate. The study of soil erosion in the watersheds under consideration reveals that only the northern portions of the SW-00, SW-02, and SW-04 watersheds require high priority conservation plans; however, these portions are primarily located in mountain regions, making the implementation of conservation plans in these areas impractical. Due to low soil loss, other sub-watersheds, particularly SW-01, SW-03, SW-05, and SW-06, are given low priority.

The integration of RUSLE-SDR lumped model with remote sensing and GIS for soil loss and sediment yield estimation

As a major contributor of land degradation, water borne soil erosion poses a threat to environmental and socioeconomic sustainability worldwide. Recently, various anthropogenic factors have aggravated soil erosion related problems in most of the humid and semi arid parts of the developing countries like India. Therefore, accurate quantification of the spatially distributed soil erosion along with the identification of erosion hot spots is of paramount significance for designing extensive management strategies to combat erosion hazard. The present study aimed to estimate mean annual soil loss in a tropical river basin such as Kumari river basin (KRB, area: 195125 ha) in the Chotanagpur plateau region in India. In addition, the study also quantified mean sediment yield and identified the main sediment sources within the basin. For these purposes, the present study introduced a raster based spatially distributed approach that integrated RUSLE and sediment delivery ratio (SDR) models with remote sensing (RS) and GIS. The results depicted that annual soil loss within the basin varied from 0 to 208.34 t ha – 1 yr – 1 with an average of 1.92 t ha – 1 yr – 1. The computed annual soil loss was about 364.05 × 103 tonnes, of these, 209.46 × 103 (∼58 %) were lost from only 8.93 % of the total basin area at intolerable rate. Similarly, the estimated sediment yield within the basin ranged from 0 to 64.53 t ha – 1 yr – 1 with a mean of 1.15 t ha – 1 yr – 1 and followed a similar distribution pattern of soil erosion. Being characterized by steep topography, the forest patches in the upstream part of the basin showed the most critical erosion risk. The methodology adopted in the current research displayed acceptable correctness and enabled spotting of most vulnerable areas of water erosion and critical sediment sources, initiating a comprehensive anticipating aid for the implementation of proper land management and soil conservation plans. This perspective is surmised to be helpful for extensive study of water erosion in other tropical river basins.

Soil erosion models verification in a small catchment for different time windows with changing cropland boundary

This paper presents very detailed studies of soil erosion within a small arable catchment located in the centre of the East European Plain. Sediment redistribution was estimated based on soil profile truncation, radiocesium methods and erosion modelling. WaTEM/SEDEM and State Hydrological Institute model were used for the evaluation of soil losses during rainfall and snowmelt, respectively. Evaluation of soil erosion and sediment redeposition was carried out taking into account historical changes in the cropland boundaries. Model estimates of soil losses from arable land are in good agreement with evaluations of erosion rates based on the results field method applications, taking into account the uncertainty of the methods. Erosion modelling made it possible to fairly plausibly estimate the decrease in soil erosion losses by approximately by a third as a result of a small (about 5%) reduction in the area of arable land in the studied catchment. The main disadvantage of applied erosion models were associated with the insufficient accuracy of estimates of the sedimentation volume and location deposition zones, mainly outside the arable land. The simulated net erosion for the entire catchment was underestimated by 3.5–4.5 times compared with field methods. This simulation block must be calibrated taking into account the regional coefficients of sediment transport in the bottoms of the dry valley network.

Behaviour of 137Cs and 210Pb inventory at three candidate reference sites for erosion study in the upstream Citarum watershed area, West Java, Indonesia

ABSTRACT The fallout radionuclide (FRN) analysis needs a reference site (RS) inventory to determine erosion and sedimentation in the study area. The investigated area is in the upstream Citarum watershed, West Java, Indonesia. Twenty-seven corings and 22 scrap samples have been prepared well and measured using HPGe gamma spectroscopy. The data below the minimum detectable activity (MDA) was found for 137Cs in RS6 cor 4 and 7 (<0.16 ± 0.08 Bq kg–1). MDA quantification implies that the inventory below MDA eroded greater than its maximum value (76.02 tons ha–1 a–1). The comparison 137Cs inventory in this study is lower than the three estimation models; however, the inventory of Mt. Papandayan is closer to the model. This study found the depth percentage of 20–30 cm using the proportion of 0–20 cm/0–30 cm ratio and predicted the portion of the existence of 137Cs and 210Pbex in the 20–30 cm in the bulk sample. The highest H0 (142.04 kg m–2), the relaxation length λ, and proportion of 20% of 137Cs in 20–30 cm depth imply that 137Cs inventory activity is possibly deeper than 30 cm. This study recommends that Mt. Papandayan could be the alternative RS for the upstream Citarum watershed.

A Study of Erosion in the Mfuti Watershed for the Sanitation and Protection of the Zamba-Telecom Road in Kinshasa/DR Congo

A Study of Erosion in the Mfuti Watershed for the Sanitation and Protection of the Zamba-Telecom Road in Kinshasa/DR Congo

A Study of Erosion in the Mfuti Watershed for the Sanitation and Protection of the Zamba-Telecom Road in Kinshasa/DRCongo

Zamba-Telecom is a road that has suffered erosion for a long time, more particularly gullying, due to poor drainage of runoff waterand uncontrolled urbanization of the area in which it is located. We carried out a hydrological study throughout the watershed in which this road is located, in order to best size a canal attached to the road, which will effectively drain rainwater upstream. According to our calculations, to better manage this water, this road must be attached to a free surface canal, with a base of 1.3 m and a height of 1.4 m to thus evacuate a total peak flow of 7.462 m3/s to the Mfutiriver. However, after carrying out a field trip, we sampled the soil from this watershedand passed it to the laboratory. It turns out that the soil of the basin is mainly made up of fine sand, the grain size of which is 0.05 to0.4 mm. For our different samples taken, the Atterberg limits gave the average value of the Plasticity Index: 8.8; the liquidity limit: 14.79 and a plasticity limit of 6, this watershed has solid, moderately plastic soil. Therefore, to protect the road from possible erosive phenomena, we should already limit urbanization in this area to limit runoff and instead encourage the infiltration of rainwater. We need to plant enough trees downstream of the watershed and develop best soil conservation practices.

Modified inderbitzen equipment for simulation of water erosion in undeformed soil samples

Several devices have been developed to assess soil losses by water erosion. However, they rarely assess the combined effects of raindrop impact and surface runoff together with vegetation cover on varying slopes. This study aimed to design and validate an equipment, on laboratory scale, to evaluate the effect of water erosion on undisturbed soil samples with and without plant cover, as well as to assess the kinetic energy of simulated rain and the resultant shear stress at varying runoff intensities. The equipment is composed of a rainfall simulator, an adjustable stand for different slopes and falling heights, and a runoff ramp for testing undisturbed soil samples measuring 15 x 20 x 40 cm (height, width, and length). In this study, the equipment simulated and evaluated the effect of precipitation and runoff on soil losses, allowing to obtain different values of the kinetic energy of precipitation and runoff. For a f low rate of 12 L min-1 and slope of 35%, the shear stress could reach up to 8 Pa. Furthermore, the equipment showed the effect of vegetation cover and slope on soil losses in different granulometric fractions (&lt; 0.106 mm, 0.106 to 0.25 mm, 0.25 to 0.5 mm, 0.5 to 1.0 mm, 1.0 to 2.0 mm, and &gt; 2.0 mm), revealing the potential of its use in several erosion studies on a laboratory scale.

Review of soil erosion modelling involving water with field applications

The literature associated with the topic of soil erosion processes is so vast that coverage must be restricted in some way. The major restriction adopted includes a focus on physically-based soil erosion modelling and its application in field studies including gully formation and sediment control methods. The choice of topics has also been biased towards those in which the authors have had some involvement, ensuring some emphasis on erosion studies in Australia and Southeast Asia.