High Erosion Research Articles

Evaluating the role of inherited structural discontinuities in badland erosional processes with landscape evolution modelling

AbstractCatchment‐wide erosion and sedimentation behaviour is influenced by variety of controls. One of these controls is erodibility, which may be determined by the lithological properties (e.g. texture, porosity) or the (density of) structural discontinuities (e.g. faults, fractures). In this study, the potential role of different erodibility of lithology and faults in spatio‐temporal erosion and sedimentation behaviour was evaluated using the landscape evolution model, Landscape Process Modelling at Multi‐dimensions and Scales (LAPSUS). The study area, Kula Badlands (western Turkey), is known for dense badland gully networks, incised into fine‐grained sediments in one of the tributaries of the Gediz River, the Geren catchment. An earlier field‐based study demonstrated the fault‐controlled net erosion and consequent sedimentation in these badlands. Here, we test the role of lithology and faults in landscape development with scenario‐based modelling. A reconstructed PalaeoDEM, representing a 30‐ka‐old landscape, was used as an input. Scenario simulations were conducted with lithology‐ and fault‐related erodibility and sedimentability factors. Simulation results demonstrate a significant difference in spatial erodibility and sedimentability and catchment erosion and sedimentation behaviour. Incorporating higher erodibility factors for fault zones caused not only a considerable amount of within‐catchment erosion in fault‐determined erosion zones, but also a decrease in overall catchment sediment export. In addition, high constant sedimentability lowers the sediment export considerably whilst slightly increasing total erosion rates. These outcomes indicate that fault zones with higher erodibility can increase accommodation spaces, producing temporary (re)sedimentation locations, which decrease overall sediment delivery from its catchment on the long run. The model simulations suggest that fault‐related higher erodibility and sedimentability can be important factors in controlling landscape dynamics at the local and catchment scale.

Rainfall Erosivity Projection in South‐East Australia Using the Improved Regional Climate Simulations

ABSTRACTRainfall erosivity is one of the most dynamic factors in the soil erosion process. The increase in soil erosion caused by high rainfall erosivity, and the subsequent loss of soil nutrients, can lead to reduced food production and ecosystem services. This research program under the New South Wales (NSW) Climate Change Adaptation Strategy, assesses rainfall pattern change, rainfall erosivity and erosion risk across NSW under future climate conditions. Daily rainfall erosivity and erosion risk were modelled by Revised Soil Loss Universal Equation (RUSLE) approach and compared with that driven by observed rainfall data. Future rainfall erosivity and soil erosion risk change were investigated from daily precipitation projection of the updated NSW and Australian Regional Climate Modelling (NARCliM1.5) for two future scenarios, RCP4.5 and RCP8.5, from the historical (1986–2005) to far future (2060–2079) periods. The annual average rainfall erosivity is projected to increase about 8% under RCP 4.5 and further decrease 5% under RCP 8.5 in NSW due to the predicted temperature rises. More frequent heavy rainfall events are projected to occur during summer (December–January–February), and the rainfall from these extreme rainfall events is expected to account for 51% of the total annual rainfall in the far future. NARCliM‐derived results underestimate annual rainfall erosivity compared with observation‐derived erosivity. There are greater instability (root mean squared error [RMSE]: 803.2) and erosivity uncertainty (Bias: 16%~48%) in high rainfall zones. At a monthly scale, dry months (June–July–August) are becoming drier, while wet months (December–January–February) are becoming wetter and more erosive. 67% of NSW is predicted to experience increased rainfall erosivity under RCP4.5, whereas most of NSW will shift to drought and its consequent effects under the high‐end emission scenario (RCP 8.5). To address the dual challenges of excessive wetness in coastal and north‐east NSW and increasing aridity in Western NSW, it is necessary to develop climate change adaptation management strategies based on high‐risk areas and monthly or seasonal conditions. With the emerging launch of NARCliM2.0, we anticipate further improvements of these predictions will be achieved by more accurate models and data at higher spatial and temporal resolutions.

Sediment transport characteristics at the flood-event scale in the Minjiang River Basin, China

ABSTRACT In recent years, the significant change in the runoff–sediment distribution in the upper Yangtze River has led to an increased sediment contribution from the Minjiang River Basin (MRB) to the Three Gorges Reservoir. However, previous studies on sediment load changes in the MRB have focused mainly on annual-scale characteristics, thereby neglecting features driven by floods. Therefore, this study focused on examining the changes in flood-event sediment loads in the MRB based on mathematical statistics and comprehensive measurement data. The results indicated that human activities, climate change, and seismic events have caused an increasing trend in the flood-scale sediment load in the upper MRB and a decreasing trend in the lower MRB. The changes in the flood-scale sediment modulus at low runoff erosion power levels were greater than those at high runoff erosion power levels at different abrupt-change stages. During extreme flood events, the actual sediment concentration in the MRB remained below the sediment-carrying capacity. This study provides novel insights into water resource management during the flood season in the MRB and similar basins.

The changes of the transit denudation in the river basin systems of the Eastern Carpathians

Two river basins were chosen for the research. Both of them are monitored by water levels, water discharge and suspended sediments runoff: the Oriava River (left tributary of the Opir River, the gauging station – Sviatoslav) and the Bystrytsia River (right tributary of the Dnister River, the gauging station – Velyka Ozymyna). Both river basins have similar catchment area, morphometric parameters, but different forestry coefficients and hydro-climatic conditions. By the research the relations between the water discharge, precipitation and suspended sediments runoff have been analyzed. The water discharge dynamics features testify about difference in the morphometric conditions of the river beds. The matching of the year precipitation and water discharges testifies about determinative role of the precipitation irregularity in the surface runoff forming. The mean annual suspended sediments runoff modules in the Bystrytsia catchment 2.3 times larger than in the Oriava catchment. But this data is not enough to conclude about lesser transit denudation and slope erosion in the Oriava basin. Therefore, with the aim of preliminary assessment of the relations between the analyzed parameters and influence of different factors including human activities the series of twin graphs for many years dynamics of the parameters. The differences in sediments granulometry of the two river systems have been ascertained. The disturbed equidistance between the graphs of testifies on some factors influences which is more characteristic for the Bystrytsia river than Oriava. This fact concords with the conclusions of the scientists concerning relatively higher level of man-made affection of the Bystrytsia River basin. Ascertaining of these factors and their quantitative assessment are the perspective task for the next research stages. The investigations also confirm the determinative influence of the granulomentric composition of sediments on the relations between the water discharge and suspended sediments runoff in the researched river systems. Since the portion of the smallest fractions of the suspended sediments is considerably bigger in the abounding in water years, this fact confirms the conclusion about high level slope erosion in such years. Absence of the fractions more than 0.5 mm in the suspended sediments load in the Oriava River may be caused by the cascade of the dams and ponds of the trout farm in its main river course. At the same time it can partly explain the higher parameters of the suspended sediments runoff in the Bystrytsia (Velyka Ozymyna) in comparison to the Oriava (Sviatoslav). To confirm such conclusions it is necessary to match and analyze the granulomentric composition of the not only suspended sediments, but also bottom ones and their transition through the river bed. Key words: river system; river catchment; water discharge; suspended sediments runoff; Bystrytsia River; Oriava River.

Impact of extreme rainfall events on soil erosion in downstream Parnaíba River Basin, Brazilian Cerrado

This study investigates the impact of extreme rainfall events on soil erosion in the downstream Parnaíba River Basin, located in the Brazilian Cerrado. The analysis focused on rainfall erosivity (R factor) and soil erodibility (K factor) as key indicators. The average erosivity in the region was 9051 MJ mm h−1ha−1year−1, with a variation between 7943 and 10,081 MJ mm h−1ha−1year−1, suggesting a high erosive potential, mainly in the rainiest months, from December to April. The soils of the studied area, mainly Ultisols and Chernosols, present high to very high erodibility, with K factor values ranging from 0.025 to 0.050 t h MJ−1 mm−1. Furthermore, fieldwork revealed areas, near highways, with apparently fragile soils, as well as rills and gullies, identified through photographs taken during fieldwork. These locations, due to the combination of high erosivity and susceptible soils, were considered prone to the occurrence of erosion processes, representing an additional risk to local infrastructure. The spatialization of R and K factors, along with field observations, showed that much of the area is at high risk of erosion and landslides, particularly in regions with greater topographic variability and proximity to water bodies. These results provide a basis for the development of mitigation strategies, being important for the effective prevention of landslides.

Spatial Assessment of Soil Erosion and Aridity in Somalia Using the CORINE Model

This study analyzed precipitation patterns, drought conditions, erosivity indices, and arid periods in Somalia using the CORINE model. Utilizing rainfall and temperature data from 50 meteorological stations collected between 2011 and 2019, the study calculated key indices: The Fournier Precipitation Index (35.70%), the Bagnouls-Gaussen Drought Index (61.36), and the erosivity index. The results revealed notable spatial variability in erosivity and aridity across Somalia. Northwestern regions, encompassing 204,978.65 km² (32.14% of the total area), exhibit low erosivity due to reduced rainfall intensity, while southern regions, spanning 252,341.11 km² (39.56%), face high erosivity driven by frequent and intense rainfall events. The study also identified significant arid conditions, with 61.36% of Somalia’s land classified as "dry" and 38.64% as "very dry," highlighting widespread water scarcity and vulnerability. These findings underscore Somalia's environmental challenges, including severe soil degradation, reduced agricultural productivity, and the exacerbation of droughts due to climate change. The integration of the Modified Fournier Index and the Bagnouls-Gaussen Index within the CORINE model provides a comprehensive assessment of the country's susceptibility to erosion and aridity. This research offers critical insights for prioritizing areas that require urgent soil conservation and improved land-use management. It also serves as a vital tool for policymakers and international organizations aiming to mitigate the adverse impacts of climate change, enhance agricultural sustainability, and promote ecological resilience in Somalia’s diverse landscapes.

Delayed environmental pollution caused by transient landscape storage - An example from the Lesser Antilles.

The strong pest pressure on intensive banana cultivation in the French West Indies led to the intensive use of chlordecone (an organochlorine insecticide) between 1972 and 1993. Due to its high toxicity for the population and the environment, many studies were conducted on the transfer of chlordecone over the last 20 years. However, most studies focused on the dissolved fraction of chlordecone, while the particle-bound fraction was understudied. Therefore, this study reconstructs pluri-decadal erosion rates (i.e. 1980-2023) and associated chlordecone particle-bound transfers from soil and sediment cores sampled in a cultivated headwater catchment (Saint-Esprit, Martinique). Based on sediment accumulation analysis in an agricultural reservoir, high erosion rates (i.e. 10 t ha-1 yr-1) were found in the investigated catchment during the study period, with values exceeding the estimated tolerable soil loss rate in tropical context (i.e. 2.2 t ha-1 yr-1). Based on the analysis of soil cores sampled along a banana plantation hillslope, this study highlights the formation of colluvial deposits with high levels of chlordecone contamination. When these areas are affected by erosion processes, this leads to massive remobilization of particle-bound chlordecone to water bodies. Indeed, in sediment sampled in the downstream reservoir, we observed a drastic increase in these transfers since 2006, synchronous with changes in agricultural practices. This study therefore highlighted the occurrence of legacy contamination at toeslope positions, which was estimated to potentially persist for 4000 to 11,000 years. Such a residence time highlights the need to implement changes in land management to effectively reduce agricultural soils erosion, particularly in areas identified as "temporary deposition zones" for chlordecone contamination, in order to protect downstream water bodies from chlordecone transfer. To achieve this, agricultural practices that may increase soil erosion, such as herbicide application or intensive ploughing, should be minimized. Overall, this study improved our understanding of erosion and associated chlordecone transfers in tropical environments.

Statistical Analysis of Short-Term Shoreline Change Behavior Along The Southern Cilacap Coasts of Indonesia

There is a threat of extreme waves and a moderate risk level of coastal erosion in Bunton Village. Based on the preliminary assessment, there is huge erosion of the shoreline and visible changes in the shoreline temporally. However, there is no statistical data on short-term shoreline change behavior in this area. Hence, this research aims to analyze statistically the short-term shoreline change behavior to understand the conditions and phenomena that occur on the coast of Bunton Village. Landsat images spanning the years 2002 to 2022, with recording intervals of 5 years each, were used to identify the shoreline data, which was later analyzed using the Digital Shoreline Analysis System (DSAS). Statistical analyses of short-term shoreline change behavior were obtained using the End Point Rate (EPR) and Net Shoreline Movement (NSM) approaches. Over a 20-year period, the Bunton coastal area experiences dynamic changes that are primarily due to erosion, with an average distance change of -255.5 meters and an average speed of -14.6 meters per year (very high erosion). The existence of the electric steam power plant (ESPP) in Adipala, which built a breakwater in 2012, has been proven to increase the erosion process. Shoreline change in this area can affect various landuses and tourism activities as well as trigger environmental problems in the Bunton coastal area.

Statistical Analysis of Short-Term Shoreline Change Behavior Along The Southern Cilacap Coasts of Indonesia

There is a threat of extreme waves and a moderate risk level of coastal erosion in Bunton Village. Based on the preliminary assessment, there is huge erosion of the shoreline and visible changes in the shoreline temporally. However, there is no statistical data on short-term shoreline change behavior in this area. Hence, this research aims to analyze statistically the short-term shoreline change behavior to understand the conditions and phenomena that occur on the coast of Bunton Village. Landsat images spanning the years 2002 to 2022, with recording intervals of 5 years each, were used to identify the shoreline data, which was later analyzed using the Digital Shoreline Analysis System (DSAS). Statistical analyses of short-term shoreline change behavior were obtained using the End Point Rate (EPR) and Net Shoreline Movement (NSM) approaches. Over a 20-year period, the Bunton coastal area experiences dynamic changes that are primarily due to erosion, with an average distance change of -255.5 meters and an average speed of -14.6 meters per year (very high erosion). The existence of the electric steam power plant (ESPP) in Adipala, which built a breakwater in 2012, has been proven to increase the erosion process. Shoreline change in this area can affect various landuses and tourism activities as well as trigger environmental problems in the Bunton coastal area.

Enhancing turbine blade durability: Evaluating protective ceramic coatings for Ti6Al4V alloy

Ti64 turbine blades face extreme conditions during solid particle erosion, accelerating the erosive and corrosive processes. Hard-coating materials such as DLC, AlTiN, TiSiN, AlCrN, and AlTiCN have been introduced through physical vapor deposition to enhance the turbine blade characteristics and increase the component lifespan. The results showed preferential orientations of (002) and (022) in coating crystallization with DLC exhibiting the highest compressive residual stress. DLC and AlTiCN coatings demonstrated fewer macroparticles and white spots, correlating with a lower coefficient of friction (COF) and surface roughness. The wear analysis revealed that DLC had the lowest COF and wear rate, followed by AlTiCN. Electrochemical tests indicated DLC's superior corrosion resistance of DLC. Although the properties of AlTiCN are comparable, DLC has emerged as the most promising coating material for achieving high erosion particle resistance in Ti64 turbine blades.

Optimization of erosion performance of biomass and pet waste based composites using artificial neural network

The determination of the potentiality of renewable energy resources holds significant importance, with biomass emerging as a crucial alternative for both energy and material needs. Consequently, predicting the mechanical properties of these resources has become a focal point. This study focuses on the analysis of fundamental products resulting from the pyrolysis process, specifically char, extracted from Polyethylene terephthalate (PET) Char, Cashew biochar, and Sugarcane biochar and examining erosion performance of polyester composites. The polyester composites subjected to erosion tests to determine their wear resistance at various impact angles. Among the studied composites, those including cashew biochar shown enhanced erosion resistance, with the least erosive wear at a 60° impact angle. The investigation aims at optimizing the erosion performance of these biomass-based composites using an Artificial Neural Network (ANN) model. The ANN was trained to predict erosive wear behavior using input factors as biochar type, filler content, and impact angle. The model effectively found ideal conditions for decreasing wear, demonstrating the potential of Cashew biochar-filled composites for applications needing high erosion resistance. This work sheds light on the successful usage of biochar fillers in improving the durability of polyester composites, presenting a sustainable alternative for materials engineering.

Numerical Prediction of Solid Particle Erosion in Jet Pumps Based on a Calibrated Model

Jet pumps are widely used in petrochemical processes, nuclear cooling, and wastewater treatment due to their simple structure, high reliability, and stable performance under extreme conditions. However, when transporting solid-laden two-phase flows, they face severe erosion problems, leading to reduced efficiency, malfunctions, or even failure. Therefore, optimizing jet pump performance and extending its service life is crucial. In this study, an experimental platform was established to conduct experiments on wall erosion in jet pumps. The CFD-DEM method was used to simulate the solid–liquid two-phase flow in the jet pump, comparing six erosion models for predicting erosion rates. The Grey Wolf Optimization algorithm was applied to calibrate model coefficients. The results indicate that the Neilson erosion model shows the best consistency with the experimental results. The inlet flow rate significantly influenced the erosion rates, while the flow rate ratio had a smaller effect. The particle concentration exhibited a nonlinear relationship with erosion, with diminishing impact beyond a certain threshold. As the factors varied, the erosion distribution tended to be uniform, but high erosion areas remained locally concentrated, indicating intensified localized erosion.

Wind erosion escalation in western Slovakia driven by climate and land use and land cover shifts

Wind erosion is a major cause of soil degradation and air pollution and is influenced by climate and land use factors. Understanding the mechanisms behind wind erosion dynamics is crucial for mitigating its harmful effects. This study employs an integrated approach, combining the Analytic Hierarchy Process (AHP) methodology and local knowledge, to comprehensively assess wind erosion in the western region of Slovakia from 2001 to 2021. Using GIS-based AHP, the study assessed the spatial distribution of areas at high risk of wind erosion based on six parameters: wind speed, surface dryness, land use, land cover, soil texture, and field slope. A multicollinearity test was conducted to examine the collinearity of the chosen factors, and it was seen that none of the factors were compromised by multicollinearity. The results showed a significant increase in the risk of wind erosion in the study area over the past 20 years, with very high erosion risk in 2007, 2014, and 2021 increasing by 37 %, 86 %, and 128 %, respectively, compared to 2001. Statistical analyses confirm the significant impact of surface dryness, wind speed, land use, and land cover on wind erosion, emphasizing the need for targeted strategies to mitigate erosion risk. The regression analysis underscores the negative relationship between land use and wind erosion, emphasizing the pivotal role of land management in erosion prevention. These findings contribute valuable insights to the discourse on sustainable land use practices and erosion mitigation, particularly in the context of evolving climate dynamics.

Land-Use-Change-Driven Erosion and Sediment Transport in the Yaqui River Sub-Basin (Mexico): Insights from Satellite Imagery and Hydraulic Simulations

Soil erosion and sediment transport are significant concerns in the Yaqui River sub-basin in northwest Mexico, driven by land use changes and environmental degradation. This study aims to evaluate erosion processes between 2000 and 2020 using a combination of satellite imagery and numerical simulations with Iber software (Version 2.5.2). The primary objective is to assess the impacts of land use changes, particularly the conversion of forest to grassland, on erosion rates and sediment transport. Satellite images from 2000 and 2020 were analyzed to detect land cover changes, while Iber’s sediment transport module was used to simulate erosion patterns based on the Meyer–Peter and Müller equation for bedload transport. Hydrological and topographical data were incorporated to provide accurate simulations of flow velocity, depth, and erosion potential. The results reveal a 35.3% reduction in forest cover, leading to increased erosion and sediment transport in steep areas. Simulation predictions highlighted areas with high future erosion potential, which are at risk of further soil loss if current trends continue. Flow velocity increased, contributing to riverbank destabilization and higher sediment yield, posing a risk to infrastructure such as the Álvaro Obregón Dam. This study underscores the need for targeted erosion control measures and sustainable land management practices to mitigate future risks and protect vital infrastructure in the Yaqui River Basin.

Studies on high temperature erosion behavior of HVOF-sprayed (Cr₃C₂-NiCr)Si and WC-Co/NiCrAlY composite coatings

The present study investigates the high temperature erosion behavior of HVOF sprayed composite coatings on T11 steel substrates by studying (Cr₃C₂-NiCr)Si and WC-Co/NiCrAlY coatings. Phase composition, cross sectional microstructure, mechanical properties, and erosion resistance were analyzed by XRD, EDS, SEM and three-dimensional optical profilography. The results demonstrate that the WC-Co/NiCrAlY coating has higher erosion resistance and oxidation stability for all temperatures and impact angles tested. Its enhanced performance in high temperature and erosive conditions is attributable to the formation of stable protective oxides such as Al₂O₃ and Cr₂O₃ and intermetallic phases such as Ni₃Al and Cr₃C₂. The NiCrAlY matrix prevents significant decarburization of WC particles, and hence phase stability and oxidation resistance. The (Cr₃C₂-NiCr)Si coating has higher microhardness due to silicide phases, but is more vulnerable to direct impacts and inferior oxidation resistance. The phase transformations for both coatings are favorable at elevated temperatures which enhances erosion resistance. The WC-Co/NiCrAlY coating is smooth and shallower in erosion craters and is perfectly suited for harsh environments demanding high toughness, impact resistance and oxidation stability. For applications in which high hardness is needed in less severe conditions, the (Cr₃C₂-NiCr)Si coating is more suitable.

Assessing watershed vulnerability to erosion and sedimentation: Integrating DEM and LULC data in Guyana's diverse landscapes

This study assesses watershed vulnerability to erosion and sedimentation in Guyana using Digital Elevation Model (DEM) and Land Use/Land Cover (LULC) classification. It aims to assess erosion risk by examining rainfall erosivity, soil types, and spatial variability. The integration of DEM-derived slope data with LULC and rainfall erosivity shows a strong correlation between high rainfall (20,809.02–31,262.35 mm) and erosivity (21,433.29–32,200.22 MJ mm ha−1 h−1 yr−1), indicating increased erosion potential, particularly in southwestern regions. Soil analysis reveals Plinthic Acrisols, with high clay content, are more prone to erosion, whereas Orthic Ferralsols are less vulnerable. Slope analysis suggests flat terrain (89.16 %) has low erosion risk, but steeper slopes require interventions. Conservation strategies like reforestation, sustainable agriculture, contour plowing, and terracing are recommended to reduce erosion impacts. This integrated assessment provides insights for prioritizing soil conservation and adaptive management to address erosion risks in Guyana.

High temperature sand erosion failure mechanism of ceramic/metal multilayer coating

This paper investigates the high-temperature erosion mechanism of TiAlN/TiAl ceramic/metal multilayer coating within the temperature range of 200 °C to 500 °C. The phase and element analysis results indicate that c-TiAlN is stable under 200°C∼500°C. The elastic modulus and hardness of TiAlN/TiAl are 230 GPa and 26.7 GPa at 200 °C. When the temperature increases to 300 °C and higher, the elastic modulus and hardness rise to 295.7 GPa and 30.5 GPa. However, the hardness and elastic modulus of TiAl coating increase from 11 GPa and 120 GPa at 200°C to 24 GPa and 260 GPa at 500°C. High-temperature sand erosion test results reveal a trend in erosion rate for the TiAlN/TiAl multilayer coating, initially increasing and then decreasing with temperature elevation. The highest erosion rate, reaching 0.6×10-3 mm3·g-1, occurs at 300 °C. Failure analysis of sand erosion indicates longitudinal cracking propagation downwards at high temperatures, merging with transverse cracks, leading to a delamination failure mode layer by layer. However, with the temperature elevation from 300 °C to 400 °C, transverse cracks shift from the interfacial layer to the TiAl layer within the TiAlN/TiAl multilayer coating. Finite element analysis demonstrates that the hardness and elastic modulus of the TiAl layer increase, leading to increased stress on the TiAl layer of the TiAlN/TiAl multilayer coating, resulting in TiAl cracking.

Mapping of soil erosion risk in Ezeagu Local Government Area of Enugu State, Nigeria

This study centres on mapping soil erosion risk in Ezeagu Local Government Area of Enugu State, Nigeria. A multi-criteria research design was adopted in carrying out this study by using remote sensed images, topographic, soil and rainfall data. K Factor, R Factor, P Factor, K Factor and Digital Elevation Model were generated. SWAT model was used to generate surface runoff and sediment yield and AHP model were used to identify and map levels of soil erosion risk in the study area. Loamy sandy soil with a K Factor value of 0.23 – 0.34 (t h MJ-1 mm-1) and loam soil with a K factor Value of 0.08 – 0.14 (t h MJ-1 mm-1) dominates the study area. The organic matter contents for all the soils were rated low with an average measured organic matter of 0.97 (%). The rainfall erosivity factor (R-factor) results showed variations across the study area from 1029.295 to 1343.092, 1343.092 to 1589.713, 1589.713 to 1744.922, 1744.922 to 1965.777, and 1965.777 to 2060.864 MJ mm ha year-1, h-1 year-1. Areas with dense vegetation had lower P-factors indicating better protection against erosion, while areas under cultivation, especially those with poor management practices and without cover crops show higher P-factors. Almost all the area has a moderate (0.5-0.6) C factor which means moderate protection, areas with higher protection (0.6-1) C factor occupied a small portion towards the east while patches of low C factors are found scattered in the north, west northwest, south and eastern part of the study area. The eastern part of the study area are more susceptible to soil erosion with value ranging from 3.2-5.8, 5.9-9.9 and 10.0-19. Slope steepness and slope length is lower in the northern, western and south-west of the study area. Areas with annual soil loss between 0 to 10 grams, 10 to 20 grams and 30 to 40 grams dominates the northern, western and southern parts of the study area. The erosion risk map depicts that very low-risk area coverage of 24.06%, low risk covers 20.29%, moderate risk occupies 17.75% and high risk erosion risk covers 21.30% while very high risk occupies 16.61% of the total area. This study recommends terracing and gabions in areas identified at risk of erosion, promotion and adoption of agronomic soil conservation methods of mulching, cover cropping and planting plants to enhance soil stability and reduce erosion.

Multi-hazard modeling of erosion and landslide susceptibility at the national scale in the example of North Macedonia

Abstract Due to favorable natural conditions and human impact, the territory of North Macedonia is very susceptible to natural hazards. Steep hillslopes combined with soft rocks (schists on the mountains; sands and sandstones in depressions), erodible soils, semiarid continental climate, and sparse vegetation cover give a high potential for soil erosion and landslides. For this reason, this study presents a multi-hazard approach to geohazard modeling on the national extent in the example of North Macedonia. Utilizing Geographic Information Systems, relevant data about the entire research area were employed to analyze and assess soil erosion and susceptibility to landslides and identify areas prone to both hazards. Using the Gavrilović Erosion Potential Method (EPM), an average value of 0.36 was obtained for the erosion coefficient Z, indicating low to moderate susceptibility to erosion. However, a significant area of the country (9.6%) is susceptible to high and excess erosion rates. For the landslide susceptibility assessment (LSA), the Analytical hierarchy process approach is combined with the statistical method (frequency ratio), showing that 29.3% of the territory belongs to the zone of high and very high landslide susceptibility. Then, the accuracy assessment is performed for both procedures (EPM and LSA), showing acceptable reliability. By overlapping both models, a multi-hazard map is prepared, indicating that 22.3% of North Macedonia territory is highly susceptible to erosion and landslides. The primary objective of multi-hazard modeling is to identify and delineate hazardous areas, thereby aiding in activities to reduce the hazards and mitigate future damage. This becomes particularly significant when considering the impact of climate change, which is associated with increased landslide and erosion susceptibility. The approach based on a national level presented in this work can provide valuable information for regional planning and decision-making processes.

Morphometric and Soil Erosion Characterization Based on Geospatial Analysis and Drainage Basin Prioritization of the Rabigh Area Along the Eastern Red Sea Coastal Plain, Saudi Arabia

Soil erosion is one of the most significant problems in global environmental development. Assigning, analyzing, and quantifying the main physical characteristics of drainage basins are powerful keys in identifying regions where there is a higher risk of soil erosion and where prompt mitigation actions are needed. Drainage basins and their drainage systems are ideally defined using the analysis morphometric parameters and their quantitative description. The present study aims to analyze morphometric parameters to prioritize drainage basins that are prone to erosion. Topographic sheets and remotely sensed digital elevation model (DEM) datasets have been prepared and analyzed using geospatial techniques to delineate drainage basins of different sizes and extract different ordered drainage systems. Based on the analysis of morphometric parameters, the Rabigh area was divided into 12 drainage basins, which significantly contribute to determining soil erosion priority levels. The present study selected and applied the most effective morphometric parameters to rank and prioritize the drainage basins of the study area after considering the crucial quantitative characteristics, such as linear, relief, and areal aspects. For each single basin, the compound factor was assigned from several morphometric parameters and applied to rank the Rabigh area. The results confirm that Basins 1, 4, 11, and 12 require a high level of soil erosion priority over an area of 2107 km2; however, Basins 3, 8, 9, and 10 have little degradation and a low level of soil erosion priority. Therefore, in the regions where high soil erosion is a factor, mitigation techniques such as terracing, filter strips, contouring, and other effective and useful structural and non-structural methods should be applied.