Extent Of Erosion Research Articles

Estimating the extent of water erosion in the Wadi Al-Rumaitha Basin, northeast of Al-Muthanna Governorate

The Wadi Rumaitha Basin is located astronomically between two latitudes (30° 39' 18" - 30° 29' 56") north, between two longitudes (45° 52' 4" - 45° 45' 10") east, with an area of (68.5) km2, located in the southern part of Iraq within the administrative borders of Al-Muthanna Governorate, which is characterized by a dry climate. The research aims to study and estimate the extent of water erosion in the Wadi Rumaitha basin, detect risks and conditions that affect the properties and quality of soil and land uses in the region, highlighting the role of natural characteristics affecting its activity, different types of water erosion prevail in the study area, between rain erosion, stream erosion, and gully erosion. The locations and areas of the basins of the river network and the stream, gully, and rain erosion network were determined, by adopting several criteria, including the Fournier equation to measure rain erosion, and the Bergsma 1982 equation (to measure the degree of stream and gully erosion, then, modeling the areas of spread of each of them, by the use of geographic information systems technology. It became clear through the research that the Fournier index in the stations of the study area reached (19.87, 21.66, 16.53), respectively, this indicates that the Wadi Rumaitha basin area falls within the range of weak rain erosion, while funicidal erosion included (4) cases limited to the range of high and very severe fluid erosion, gully erosion included (7) areas confined between the (very light and very high) ranges, and their geographical distribution varies in the basin lands.

The role of artificial intelligence data in estimating the extent of gully erosion the basin is Wadi Khashm Al-Mujadar

Wadi Khashm Al-Mujadar basin is one of the dry valleys in the southern western plateau of Iraq, it is located astronomically between two latitudes (5314.191◦29) (2437.944◦29) north, and (102.327◦46) (02.79◦46) east. It is characterized by geomorphological, hydrological and natural resource characteristics, contributes to the development of the lands of the southern Western Plateau. The importance of the topic comes from the natural and human characteristics of this basin that contribute to development, with artificial intelligence data, it has become an important tool in the process of analyzing, linking, interpreting and modeling some natural risks, to which the soil and lands are exposed under varying climatic conditions that contribute to the variation in the quality and extent of erosion. The use of artificial intelligence data is an effective tool in achieving valuable and accurate results. The research aims to use artificial intelligence data to estimate the extent of erosion, determine its type, cases, and degree of severity, and model it, depending on the results of the calibrations used, especially the Bergsma criterion for determining groove erosion. Gully erosion in the basin varies from light gully erosion to high gully erosion, due to the variation in the amount of rain, its falling regime, and the characteristics of the soil in the region, in addition to the rock formations, the steepness of the slope, the density of natural vegetation and the role of humans in it. The study showed that there are (4) erosion zones: it is a very light erosion zone(13.03 km2 and a rate of 4.28%), the area of light erosion (218.35 km2, at a rate of 71.81%, the moderate erosion zone (68.71 km2, at a rate of 22.6%, and the high erosion zone (3.99 km2, at a rate of 1.31%. The majority of the area was located within the range of light and moderate erosion, requires finding ways to reduce soil erosion and the deterioration of its structure, composition and natural properties.

Research on Sediment Erosion and Anti-Wear Coating Materials for Water-Intake Components of Hydraulic Turbines in Sandy Rivers

The operational efficiency, stability, and lifespan of hydroelectric power plants operating on sediment-laden rivers are affected by sediment erosion. A numerical simulation of the sand–water flow in the water-intake components of a turbine at a specific power station was conducted using the Euler–Lagrange method. Additionally, sediment erosion tests were carried out on the water-intake components coated with epoxy mortar material. The results indicate that sediment erosion on the stay vane surface mainly occurs on the front face, with the most severe erosion at the head, while sediment erosion on the stay ring surface primarily occurs near the stay vane head. The extent of erosion is mainly influenced by the distribution characteristics of sediment particles. The wear of epoxy mortar coating material is minimally affected by the spraying thickness. Adding 30% hardener to the epoxy mortar material can significantly improve the erosion resistance of the stay vane surface by about 30%. The erosion rate on the frontside of the stay vane is approximately 2.6 times that of the backside. Based on the sediment erosion tests and numerical simulation results of the sand–water flow, an estimation formula for the sediment erosion rate of the epoxy mortar erosion-resistant coating was established. This formula can be used to predict the anti-sediment erosion performance of epoxy mortar materials applied to the water-intake components of this turbine and similar river turbines.

The Derim Derim Dolerite, greater McArthur Basin, Australia: Using subsurface data to characterise a mesoproterozoic magma plumbing system

The application of high-resolution seismic reflection data has spurred major advances in knowledge of the emplacement of sub-volcanic mafic magma plumbing systems in sedimentary basins, highlighting the importance of interconnected sheet intrusions in facilitating lateral magma transport, the links between host rock mechanical properties and emplacement processes, and providing insights into how intrusive activity in basins impacts their resource potential. However, most studies have focused on Mesozoic-Cenozoic mafic magma plumbing systems situated along offshore rifted margins characterised by extensive subsurface datasets. The extensive Mesoproterozoic (c. 1300 Ma) Derim Derim Dolerite, which intrude the greater McArthur Basin in northern Australia, provide a unique opportunity to study the emplacement of a Proterozoic magma plumbing system due to its penetration by numerous hydrocarbon and mineral drillholes, in addition to seismic reflection coverage. Understanding the emplacement of this system is important because of its interactions with prospective unconventional shale reservoirs in the Velkerri and Kyalla Formations, which represent one of the world's oldest known petroleum systems. This paper focuses on characterising the intrusion emplacement and magma plumbing system using an array of subsurface data, to constrain the distribution, morphology, and emplacement mechanisms of the Derim Derim Dolerite.The morphology of the large, strata-concordant intrusions encountered at shallow present-day depths (<2 km) in the greater McArthur Basin is indicative of greater original emplacement depths of >3–4 km, suggesting a significant extent of uplift and erosion. Density-derived porosity values for the Velkerri and Kyalla Formations are anomalously low for their present-day depths, corroborating a greater palaeo-depth at time of emplacement. The extent of alteration of the host rock surrounding the Derim Derim Dolerite is highly variable, with a small number of occurrences of graphitisation of the organic matter adjacent to intrusions. However, this appears to be highly localised and the detrimental impact of the Derim Derim Dolerite on potential reservoir and/or source rocks appears generally minimal.

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

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

Synergy effects of cavitation and particle erosion based on the Erosion/Corrosion Research Center erosion model

This study presents a new synergy model that incorporates the accelerated motion of particles resulting from bubble collapse. The model uses the Erosion/Corrosion Research Center erosion model to predict the combined effect of cavitation and particle erosion on wall surfaces. The results show that, compared with the conventional erosion model, the synergy model reduces the error in the erosion mass loss by up to 24.60%. The significant improvement in prediction accuracy confirms the effectiveness of the synergy model. The severity of sample erosion is positively correlated with the cavitation-inducer angle. The synergy effect leads to an increase in the extent and severity of erosion. Smaller particles demonstrate a more pronounced synergy effect, resulting in significantly accelerated motion and a highly concentrated particle distribution. High erosion rates are associated with high-speed impacts and small-angle impact zones, primarily caused by high-speed cutting erosion. This study presents a novel prediction method for exploring the synergy effect of cavitation and particles on wall erosion and investigates the motion characteristics of particles under this effect.

The study on interaction mechanisms between Ti48Al2Cr2Nb alloy and Y2O3 ceramic crucibles with good thermal shock resistance: Assessing a novel, cost-effective approach to the preparation of high-performance TiAl alloys

Enhancing the thermal shock resistance of Y2O3 ceramic crucibles, coupled with advancements in melting and casting technologies to reduce the adverse influence of interfacial reactions, is essential for producing low-energy consumption, high-quality titanium-aluminum (TiAl) alloys. In this study, the Y2O3 ceramic crucible with good thermal shock resistance was developed through the optimization of particle size distribution and sintering holding time. The interaction mechanisms between Y2O3 ceramics and TiAl alloys under extreme conditions were investigated, and strategies for enhancing the mechanical properties of TiAl alloys through the integration of Y2O3 crucibles with centrifugal casting were discussed. The results indicated that introducing large particles of 1–3 mm under sintering conditions of 2023 K and 6 h effectively enhances the thermal shock resistance of Y2O3 crucible. The interaction between Y2O3 and TiAl alloys primarily involved physical erosion (spalling/dispersion), dissolution of separated particles, and surface modification of interface layer particles (reaction). Physical erosion played an important role in this dynamic interaction, with the extent of erosion intensifying through continuous use of the crucible, while electromagnetic forces ensured the uniform distribution of inclusions within the TiAl alloy matrix. Moreover, the application of centrifugal casting technology substantially refines the grain size and reduces the inclusion count, thereby significantly enhancing the mechanical properties of TiAl alloy.

A framework for national-scale coastal storm hazards early warning

National weather forecasting agencies routinely issue a range of hazard warnings. But to our knowledge, along sandy coastlines where storm waves and storm surge can result in widespread but location-specific beach erosion and beachfront flooding, no national-scale early warning service for these hazards is presently operational. This paper outlines the scientific basis and implementation of a new framework for large area coastal storm hazards forecasting, currently being tested along the southwest (Indian Ocean) and southeast (Pacific Ocean) coasts of Australia. The system provides 7-day rolling predictions of localized beach erosion and/or coastal flooding linked to forecasted extreme weather events. Coastal setting influences the nature and occurrence of these hazards, with sandy beaches along wave-dominated coasts more prone to erosion and at surge-dominated coasts to flooding. An existing nearshore water-level forecasting system and a new inshore wave modeling capability are used to forecast beach erosion and coastal flooding at every 100 m along the shore. At the regional scale O(100–1 000 km of coastline), a threshold-based decision tree model categorises the predicted extent, location, and severity of erosion and flooding. At a more local scale O(100–1 000 m), physics-based modeling using XBeach focuses on vulnerable or high-value locations, providing specific storm hazard indicators tailored to local needs. This two-tier approach is feasible for national implementation due to the reduced computational effort, limiting intensive modeling to pre-identified critical locations. Delft-FEWS manages the data and modeling workflow, ensuring scalability and compatibility with existing forecast infrastructure. Initial evaluations of the system are promising, with a detailed 2-year evaluation in progress. Future enhancements could include the use of satellite imagery for real-time beach width and dune topography assimilation and exploring alternative modeling approaches to further improve forecast accuracy.

Application of Remote Sensing for Identifying Soil Erosion Processes on a Regional Scale: An Innovative Approach to Enhance the Erosion Potential Model

Soil erosion represents a complex ecological issue that is present on a global level, with negative consequences for environmental quality, the conservation and availability of natural resources, population safety, and material security, both in rural and urban areas. To mitigate the harmful effects of soil erosion, a soil erosion map can be created. Broadly applied in the Balkan Peninsula region (Serbia, Bosnia and Herzegovina, Croatia, Slovenia, Montenegro, North Macedonia, Romania, Bulgaria, and Greece), the Erosion Potential Method (EPM) is an empirical erosion model that is widely applied in the process of creating soil erosion maps. In this study, an innovation in the process of the identification and mapping of erosion processes was made, creating a coefficient of the types and extent of erosion and slumps (φ), representing one of the most sensitive parameters in the EPM. The process of creating the coefficient (φ) consisted of applying remote sensing methods and satellite images from a Landsat mission. The research area for which the satellite images were obtained and thematic maps of erosion processes (coefficient φ) were created is the area of the Federation of Bosnia and Herzegovina and the Brčko District (situated in Bosnia and Herzegovina). The Google Earth Engine (GEE) platform was employed to process and retrieve Landsat 7 Enhanced Thematic Mapper plus (ETM+) and Landsat 8 Operational Land Imager and Thermal Infrared Sensor (OLI/TIRS) satellite imagery over a period of ten years (from 1 January 2010 to 31 December 2020). The mapping and identification of erosion processes were performed based on the Bare Soil Index (BSI) and by applying the equation for fractional bare soil cover. The spatial–temporal distribution of fractional bare soil cover enabled the definition of coefficient (φ) values in the field. An accuracy assessment was conducted based on 190 reference samples from the field using a confusion matrix, overall accuracy (OA), user accuracy (UA), producer accuracy (PA), and the Kappa statistic. Using the confusion matrix, an OA of 85.79% was obtained, while UA ranged from 33% to 100%, and PA ranged from 50% to 100%. Applying the Kappa statistic, an accuracy of 0.82 was obtained, indicating a high level of accuracy. The availability of a time series of multispectral satellite images for each month is a crucial element in monitoring the occurrence of erosion processes of various types (surface, mixed, and deep) in the field. Additionally, it contributes significantly to decision-making, strategies, and plans in the domain of erosion control work, the development of plans for identifying erosion-prone areas, plans for defense against torrential floods, and the creation of soil erosion maps at local, regional, and national levels.

Evaluation of sand subgrade seepage erosion caused by buried pipeline leakage

Leakage from buried pipelines can lead to an increase in the water content of the subgrade soils and a rise in the water table, leading to soil loosening, erosion and ultimately the formation of hidden voids and roadway collapses. This study presents a discrete-element method and validates its accuracy by utilising cavity data from model experiments. It investigates the mechanism of seepage erosion resulting from pipe leakage and analyses the development of the soil arch effect. Furthermore, it discusses the influence of sand void ratio and particle size on sand seepage erosion. The results indicate that the erosion area is primarily affected by the void ratio and particle size. In comparison to soil particles ranging from 0.1 to 5 mm and from 2 to 5 mm, those with sizes between 0.1 mm and 2 mm generate areas of erosion and loosening that are approximately 40% larger. The proposed model offers a precise analysis of the developmental process and the extent of seepage erosion, thereby contributing to the prediction of potential road cavity areas based on dynamic changes in key factors such as subgrade soil type and groundwater level.

Cumulative sedimentation hazard map of urban areas subject to hyperconcentrated flash flood: A case study of Suide County in the Wuding River basin, China

AbstractFlash floods can carry substantial sediment, posing significant sedimentation hazards in hilly cities. The sedimentation hazard map can reproduce the sediment thickness and extent of an extreme events scenario, playing an important role in sediment risk management. However, current research primarily focuses on modeling the inundation area and depth of floods, while studying sedimentation hazard caused by flash floods in urban areas remains insufficient. This paper aims to address this gap by utilizing a numerical model that simulates hyperconcentrated flow in hilly urban areas using the two‐dimensional hydro‐sediment‐morphological model to compile the cumulative sedimentation hazard map. The model, built upon the open‐source TELEMAC‐MASCARET framework, incorporates Zhang Hongwu's formula to simulate sediment‐carrying capacity, particularly suitable for hyper‐sediment concentration near the riverbed. This paper uses the data of extreme flash flood events in the Wuding River basin in 2017 to simulate and compile the cumulative sedimentation hazard map. The hazard map delineates the sedimentation hazard extent and level attributable to overbank floodplain sedimentation. Notably, the sediment thickness is highest in areas near the levees on both sides of the Dali River. Moreover, the map illustrates the extent of channel erosion resulting from hyperconcentrated floods, which could jeopardize bank stability.

Interfacial microstructure of diamond/SiC composites fabricated by Si infiltration with gas flow guidance

To preserve the structural and interfacial integrity of diamond, diamond/SiC composites were fabricated by Si infiltration under gas flow guidance. The characteristics of these materials are significantly affected by the interfacial reaction between Si and diamond. The interface formation was studied extensively by locally analyzing the microstructure of the interfacial regions via transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and X-ray diffraction (XRD). The results demonstrated that the extent of reactive erosion of diamond by Si weakened as the gas velocity increased during the infiltration process. Nanocrystalline Si5C3 and β-SiC grains with an orientation relationship were observed at the diamond/SiC interface. Furthermore, by employing gas flow guidance, the diamond/SiC composites exhibited a better specific stiffness, measuring up to 183.3 × 106 m2 s−2, which represents an exceptional 18 % improvement compared with the control group.

Estimating the extent of erosion using the RUSLE coefficient for Wadi Al-Karmashiya, northeast of Wasit Province

Soil loss is a major cause of land degradation all over the world, especially in large areas of arid and semi-arid regions. The objectives of the study were to estimate the extent of erosion and soil erosion using several indicators, especially the effect of rain coefficient, soil erodibility coefficient, slope coefficient, and cover coefficient. Plant and soil conservation factors, through RUSLE laboratories, as well as employing geographical information systems to obtain results related to soil erosion in the Karmashiya Basin, as the study showed that the volume of erosion in the basin ranged between 5-265 tons/ha/year, and that the areas most affected by erosion Those extending along the waterways, especially the central and southern regions of the basin, as well as the agricultural areas spread over a diverse area of the basin’s lands, especially those that do not follow modern methods of tillage and irrigation.

Study on surface erosion threshold and erosion mass of bentonite applied in nuclear waste repository based on fractal structure characteristics

Bentonite exhibits good self-sealing performance and low permeability after hydration, and therefore is selected as a buffer material for high-level radioactive waste repositories, isolating the canisters containing nuclear waste from the external environment. The bentonite cushion directly contacts the surrounding rock and generates gels at the contact interface with fracture water. Surface erosion occurs once the shear stress exerted by the flowing water exceeds the erosion threshold of the bentonite gel, resulting in gel particle detachment from the soil–water interface and transport through fissure. The mass loss of the buffer by erosion will weaken its functionality as designed and directly endanger the long-term safety of the repository. The erosion behavior of bentonite is related to the structure of the gel formed by bentonite hydration. In this paper, the X-ray small-angle scattering experiments were used to prove that the gel structure has fractal characteristics and to obtain the mass fractal dimension. Based on the fractal structure of the bentonite gel, the erosion threshold that determines whether erosion will occur was quantified as a function of the solid volume fraction of the gel by taking the inter-particle attractive bond as the primary source of resistance. Furtherly, the cumulative erosion mass model that evaluates the extent of erosion was constructed to reveal the relationship between the cumulative erosion mass and cumulative water flow after the erosion has achieved stability. The proposed relations are verified by the experimental results from published literature and are of great significance for judging whether erosion will occur and evaluating the degree of erosion.

The combined effects of tide and storm waves on beach profile evolution

Meso- to macro-tidal beaches are extensively distributed around the world. Water level determines the location where wave action can reach. Tide induced water level changes are the main component of total water level during typhoon landfall, which determines the extent and degree of beach erosion. Considering the tidal level wave height variation process in physical model experiments is crucial for the evaluation of beach erosion. This study presents the results of a new set of beach profile evolution process which considers the combined effects of tide and storm waves. Compared with the mean tidal level situation, tide induced water level variations significantly changes the erosion pattern of profile. The maximum erosion magnitude decreases by about 60% and the horizontal range increases by about 25%.

An Events-Based Approach to Understanding Democratic Erosion

ABSTRACTThis article introduces and demonstrates the utility of a new event dataset on democratic erosion around the world. Through case studies of Turkey and Brazil, we show that our Democratic Erosion Event Dataset (DEED) can help to resolve debates about the extent to which democracy is backsliding based on prominent cross-national indicators, focusing in particular on the Varieties of Democracy (V-Dem) and Little and Meng (L&amp;M) indices. V-Dem suggests that democracies are deteriorating worldwide; L&amp;M argue that this may be an artifact of subjectivity and coder bias and that more “objective” indicators reveal little to no global democratic backsliding in recent years. Using DEED, we show that—at least in these cases—objective indices may underestimate the extent of democratic erosion whereas subjective indices may overestimate it. Our analyses illustrate the ways in which DEED can complement existing indices by illuminating the nature and dynamics of democratic erosion as it occurs on the ground.

Degradation and Erosion of Metal-Organic Frameworks: Comparative Study of a NanoMIL-100 Drug Delivery System.

To make a drug work better, the active substance can be incorporated into a vehicle for optimal protection and control of the drug delivery time and space. For making the drug carrier, the porous metal-organic framework (MOF) can offer high drug-loading capacity and various designs for effective drug delivery performance, biocompatibility, and biodegradability. Nevertheless, its degradation process is complex and not easily predictable, and the toxicity concern related to the MOF degradation products remains a challenge for their clinical translation. Here, we describe an in-depth molecular and nanoscale degradation mechanism of aluminum- and iron-based nanoMIL-100 materials exposed to phosphate-buffered saline. Using a combination of analytical tools, including X-ray photoelectron spectroscopy, nuclear magnetic resonance spectroscopy, small-angle X-ray scattering, and electron microscopy, we demonstrate qualitatively and quantitatively the formation of a new coordination bond between metal(III) and phosphate, trimesate release, and correlation between these two processes. Moreover, the extent of material erosion, i.e., bulk or surface erosion, was examined from the transformation of nanoparticles' surface, morphology, and interaction with water. Similar analyses show the impact of drug loading and surface coating on nanoMIL-100 degradation and drug release as a function of the metal-ligand binding strength. Our results indicate how the chemistry of nanoMIL-100(Al) and nanoMIL-100(Fe) drug carriers affects their degradation behaviors in a simulated physiological medium. This difference in behavior between the two nanoMIL-100s enables us to better correlate the nanoscale and atomic-scale mechanisms of the observed phenomena, thus validating the presented multiscale approach.

Assessment of Riverbank Erosion and Accretion and its Impact on the People of Chairman Ghat, Noakhali, Bangladesh

Nestled within the vastness of the Meghna deltaic plain, Noakhali, and in particular, Chairman Ghat, stand as poignant examples of Bangladesh's intricate relationship with environmental challenges. The significance of the Meghna deltaic plain cannot be overstated, as it shapes the very fabric of the nation's landscape. However, this geographic richness comes hand-in-hand with vulnerability, and nowhere is this more apparent than in the relentless grip of riverbank erosion. Chairman Ghat, in Noakhali, epitomizes the struggle against this natural force, making it a focal point for understanding and addressing the profound impact of riverbank erosion in the region. The primary objective of this research work is to assessing river bank erosion &amp; accretion and examine its the potential impact in the chairman Ghat area. In order to achieve this goal, this study employs remote sensing and GIS techniques to assess the erosion and accretion rates of Chairman Ghat on the Noakhali coast from 2000 to 2022 and conduct household survey to examine the socioeconomic impacts of river erosion on the local population. The findings revealed that Over the past 22 years, the Meghna estuary experienced a total of 667.0 km2 of erosion and 689.1 km2 of accretion. Chairman Ghat area alone witnessed a net erosion rate of 4.2 km2 per year during the specified period, resulting in a loss of 117.7 km2 of land, while only 25.3 km2 of new land was added. From household survey it is found that the adverse effects of riverbank erosion on the local community are evident, leading to the loss of vital agricultural lands, homesteads, and property damage that cannot be easily recovered. Consequently, a significant portion of the affected population is compelled to migrate, thereby exacerbating their socio-economic plight as they are forced to change professions. This research sheds light on the extent of riverbank erosion in Chairman Ghat, Noakhali, and elucidates its profound socioeconomic implications on the lives of the local inhabitants. The findings of the study will help to enhance our understanding of the specific impact of river erosion enabling the development of targeted strategies to protect vulnerable communities' lives, livelihoods, and environments. It will also promote cohesive coastal zone management, implementing robust measures that counteract the destructive consequences of riverbank erosion, thereby ensuring the sustainable development and resilience of these crucial ecosystems.

Runoff and erosion from three unpaved road segments in northern Vietnam

Study regionTruong Son Commune, Luong Son District, Hoa Binh Province in north Vietnam. Study focusRunoff and erosion from three road surface and three adjacent cutslope plots in a young plantation forest to evaluate how unpaved forest roads affect runoff and erosion. New hydrologic insights for the regionThe 10-m long road surface plots generated similar amounts of runoff with runoff coefficients of 24–32 % over 24 rainstorms divided into an initial wetter period followed by a relatively drier period. Runoff coefficients for the two monitoring periods were not statistically different, and the relatively low runoff coefficients compared to previous studies were due to infiltration outside the narrow compacted tracks created primarily by motorbike traffic. Runoff from the base of the cutslopes varied by a factor of three, associated with the topographic convergence of the hillslopes. Road surface erosion over the two monitoring periods was consistent among the three plots and storm-based sediment production was strongly correlated with both storm precipitation and surface runoff. The amounts of runoff and sediment collected at the base of the cutslopes increased with increasing hillslope convergence, and the mass of collected sediment was 52–97 % of the corresponding amounts from the road surface plots. The results provide data on the extent of unpaved road runoff and erosion in this seasonally wet tropical environment, and the need to consider topographic convergence in road design and drainage.

The condition of cervical tooth wear and association with brushing habits among students of Hue University of Medicine and Pharmacy

Background: Cervical tooth wear is a common oral health issue that often leads to the loss of tooth structure integrity, making the teeth sensitive, prone to plaque buildup, affecting the dental pulp, and causing aesthetic concerns. Assessing the extent of tooth erosion and its correlation with brushing habits is crucial for enhancing the effectiveness of necessary interventions and preventive measures. Objective: To determine the prevalence and severity of cervical tooth wear in young individuals aged 18-25 and examine the association between brushing habits and cervical tooth wear. Methods: A cross-sectional descriptive study was conducted on 60 undergraduate students from the Hue University of Medicine and Pharmacy, aged 18 - 25, who visited the Odonto-Stomatology Clinic, Family Medicine Center from November 2020 to April 2021. Study participants were interviewed and provided clinical examinations after obtaining their consent. Results: The study findings revealed a relatively high prevalence of cervical tooth wear (53.3%). Most cases exhibited a severity score 0 (no tooth wear), and no cases were classified as score 4. The highest prevalence of cervical tooth wear was observed in the left mandibular (65.6%). Regarding the association between cervical tooth wear and brushing habits, there was a significant correlation between horizontal brushing technique and brush hardness with cervical tooth wear (p &lt; 0.05). However, there was no significant correlation between brushing frequency, toothbrush replacement time, brushing duration, and force applied during brushing with cervical tooth wear (p &gt; 0.05). Conclusion: In general, the prevalence of cervical tooth wear is relatively high, and there exists a correlation between horizontal tooth brushing habits and brush hardness with the condition of cervical tooth wear. Therefore, implementing preventive measures against cervical tooth wear is crucial for enhancing oral health for everyone. Key words: cervical tooth wear, brushing habits, brush hardness, student.