Erosion Response Research Articles

Spatial Scale Effects on Erosive Runoff and Sediment Flow Behavior on Loessial Slopes: An Erosive Energy Basis

ABSTRACTRunoff erosion response associated with sediment transport as influenced by erosive energy variability is a highly scale‐dependent process. Identifying the spatial scale effect on erosive runoff energy is important to understand the spatial pattern of sediment flow behavior across various sites. This issue was resolved by establishing thresholds for erosive runoff based on frequency analysis, which considered four selected threshold parameters: runoff duration (T), stream power (ω), stream energy factor (SE), and area‐specific sediment yield (SSY). Based on these thresholds, 77 erosive events were identified and separated from nonerosive events for further analysis of energy–sediment relationships. The threshold for T was roughly constant at hillslopes but rapidly increased at the entire slope. Thresholds for ω and SE exhibited positive linear relationships with the plot area, whereas the threshold for SSY showed a general increasing trend along the downslope direction. The R2 values of erosive energy–sediment relationships at inter‐ and intra‐event time scales were generally higher for erosive events than for nonerosive events. The sediment delivery capacity (Cd) for erosive runoff ranged from 0.075 to 0.115 kg·m·J−1. It demonstrated an initial increase followed by a subsequent decrease from the upper hillslope to the entire slope. Conversely, Cd for nonerosive runoff increased with the rise in plot area, and it ranged from 0.053 to 0.083 kg·m·J−1. The sediment‐increasing capacity (Ci) for erosive runoff ranged from 0.43 to 4.47 kg·m−2·W−1, whereas Ci for nonerosive runoff varied from 3.39 to 17.6 kg·m−2·W−1. The sediment reduction benefit by regulation unit stream energy factor varied from 5% at the entire slope to 65% at the upper hillslope. Therefore, anti‐erosion measures should be implemented at the upper hillslope to prevent nonerosive runoff from becoming erosive runoff.

Comparing the effects of hydromulching and application of biodegradable plastics on surface runoff and soil erosion in deforested and burned lands

Abstract Several techniques, such as hydromulching (HM) and addition of organic residues (such as biodegradable plastics, BP) to soil have been proposed for conservation of soil affected by deforestation and wildfire. However, there is the need to support the task of land managers for the adoption of the most effective soil conservation technique, considering that the impacts on soil properties and hydrology are different due to the different mechanisms (mainly based on root actions for hydromulching and on supply of organic matter for application of bioplastics residues). This study comparatively evaluates the hydrological and erosive effects of HM, addition of BP residues to soil, and lack of any treatments (control) at the plot scale and under simulated rainfall in deforested and burned forestlands of Northern Iran. These effects have been associated to changes in key properties of soil and root characteristics due to the treatments, using multivariate statistical analysis. Moreover, regression models have been setup to predict surface runoff and soil erosion for both treatments. HM was more effective (–65% of runoff and –61% in soil loss) than application of BP (–22% and –19%, respectively) in controlling the soil’s hydrological and erosive response, the latter being extremely high in control plots (over 6 tons/ha). These reductions were closely associated to significant increases in organic matter and aggregate stability of soil, to a decrease in bulk density after the treatments, and to the grass root growth, which further improved soil hydrology after HM. The Principal Component Analysis provided a synthetic parameter measuring the soil response to rainfall and treatments. The cluster analysis discriminated the three soil conditions (HM, application of BP and control), according to the changes in soil properties and root growth in HM, in as many groups of soil samples. The multiple regression analysis provided two linear models that predict surface runoff and soil loss with a very high accuracy (r2 > 0.98) for a precipitation with given depth and intensity.

Erosional Response to Pleistocene Climate Changes in the Brazilian Highlands

AbstractPlio‐Quaternary climatic changes are considered to be a key driver of landscape evolution, but many unresolved questions remain, such as the extent of the impact of major climatic shifts such as the Mid‐Pleistocene Transition (MPT). Various geochronological methods are available to infer changes in surface processes over the Plio‐Quaternary, and Terrestrial Cosmogenic Nuclides (TCN) have proven to be one of the most efficient tools to reconstruct paleo‐denudation. Implementing these approaches requires very specific conditions, such as well‐preserved and extensive sediment sequences. Developing alternative methods to document the evolution of denudation is thus of major interest to retrieve information on the evolution of denudation in places where recent detrital sediment records are absent. We explore the evolution of landscape erosion over a 1 Ma timescale in an intra‐cratonic setting, the Espinhaço mountain range (Brazil), with a new data set of detrital cosmogenic nuclide concentrations (26Al–10Be). We observe a systematic disequilibrium in the 26Al/10Be ratio, which we interpret as resulting from the combination of soil mixing and a significant increase in the intensity of surface processes, close to the MPT. We discuss the different scenarios with respect to available local and global data concerning the relationships between climate evolution and erosion over this time period. Our results have important implications for the interpretation of the denudation rates derived from TCN concentrations under steady states assumption, in landscapes with low erosion rates, which have a long memory for surface processes history.

Exploring the inclusion of soil management practices in erosion models towards the improvement of post-fire predictions

Wildfires are recognized for having a strong impact on forest soils, a situation aggravated by inadequate pre-fire land management practices. Land management operations, such as plowing, are routinely carried out for cultural reasons and can impact soils for decades after their implementation. Therefore, it is crucial to take into account the pre-fire land management history when predicting post-fire sediment losses in burnt areas. This consideration is critical for a realistic assessment of soil erosion risk and, consequently, for effectively implementing emergency stabilization and/or rehabilitation measures.The aim of the study was to integrate pre-fire land management practices into erosion models, to enhance post-fire sediment losses predictions at slope scale. To accomplish this goal, both Multiple Linear Regression (MLR) and the revised-Morgan-Morgan-Finney model (revised-MMF) were applied in the Colmeal burnt area (Central Portugal). These models were adapted to account the impacts of different management options, specifically no plowing, downslope-plowing and contour-plowing, on the erosive response following a wildfire.The results revealed fluctuations in the performance of both models across different soil management, and over time since the wildfire. Despite the observed variability, it is important to highlight the positive outcomes achieved with the revised-MMF model over the three monitoring years where contour-plowing was applied. These results demonstrate that the best model performances are achieved when soil management is individualized and analyzed independently. Similarly, the MLR model exhibited improved performance when incorporating management practices into its predictions. This study confirms that disturbances on topsoil, whether caused by wildfires or soil management operations, play key roles in driving change in soil erosion. Hence, integrating these factors into models is essential for providing relevant information for the development of mitigation and/or restoration strategies in areas at high risk of erosion.

Sensitive response of erosion and weathering to the Indian Summer Monsoon changes in South Asia during Dansgaard-Oeschger oscillations

Continental weathering plays a key role in regulating the long-term climate stability via negative feedback. However, whether and how erosion and weathering respond to rapid climate change (e.g millennial scale) in large river basins remains unclear, partly due to the lack of archives with robust age models and high sampling resolution. As one of the largest sediment source-to-sink systems, the Himalaya-Ganga/Brahmaputra River-Bay of Bengal system is considered as an ideal laboratory for examining the weathering-climate relationships over the past. Here we present the elemental and mineralogical data from well age-constrained core sediments in the Bay of Bengal, which document the erosion and weathering conditions in South Asia during the last glacial period. All proxies generally show larger values during glacial interstadials than the stadials, consistent with the millennial variabilities of regional sea surface temperature (SST) and the Indian Summer Monsoon (ISM) strength. We confirm that the erosion and chemical weathering signals in Ganga/Brahmaputra River basins, which sensitively respond to the ISM strength and/or temperature change, could be propagated through the large river systems and faithfully preserved in the South Asian marginal seas, without noticeable time lag on a millennial scale. Our findings provide valuable data for response of erosion and weathering dynamics in a large river basin to rapid climate changes, and highlight the immense potential of monsoon-driven continental silicate weathering in floodplains as a substantial short-term carbon sink, thus underscoring a pivotal natural carbon sequestration mechanism amidst the escalating threat of global warming.

Soil erosion responses of cropland uses in contrasting slope in the Abay basin, Ethiopia

Cultivated land is the primary source of runoff and soil loss in a watershed. Quantifying the soil erosion response of dominant cereal crops at different slope gradients is vital to sustainable land use, crop management, and conservation options. This study evaluated the runoff loss (Ro), runoff coefficient (RoC), and soil loss (SL) responses of teff (Eragrostis tef), maize (Zea mays), and wheat (Triticum aestivum) cropland use under different slope conditions. During 2020 and 2021, 18 experimental erosion plots (3 m × 10 m) having 3 crops × 3 slope gradients (8%, 18%, and 32%) with two replicates were installed. Soil loss and runoff analysis were made and the significance variation among land uses and slopes was tested using ANOVA. On average, the highest Ro is recorded from teff land use (700 mm) followed by wheat (651.2 mm), and maize (570 mm) land uses. The Ro generated from the teff crop land use exceeds 18.5% and 6.9% compared to maize and wheat crop land uses (P < 0.05). The lower proportion of the rainfall was converted to runoff (RoC = 38%) under the maize crop land use, however, nearly half of the rainfall (RoC = 46.6%) became runoff in the teff crop. The average (three slope gradients) rate of SL in teff, wheat, and maize crop land uses was found to be 54.86, 45.61, and 38.27 t ha−1 year−1, respectively. Although the result shows high soil erosion in all cereal crops, cultivation of the teff crop in general and on steep slopes in particular leads to a high Ro and SL. Therefore, sustainable land management practice and setting land use policy are recommended, particularly for teff cultivation.

Numerical Simulation of Rainfall-Induced Erosion on Infiltration and Slope Stability

In slopes where a mixture of coarse and fine particles is present, the infiltration of rainfall can cause the migration of fine particles. This migration alters the hydraulic properties of the soil and has implications for slope stability. In this study, the slope under investigation is a tailings dam composed of loosely consolidated soil with a wide particle size distribution. Due to rainfall infiltration, fine particles tend to migrate within the voids of the coarse particle framework, leading to changes in hydraulic properties and inducing slope instability. The classical internal erosion constitutive model, known as the Cividini and Gioda erosion criterion, is commonly used to predict the behavior and effects of fine particle erosion in geotechnical engineering. However, certain parameters in this erosion criterion equation, such as long-term density, are challenging to obtain through experiments. To investigate the coupled evolution of seepage and erosion within landfill slopes under the influence of rainfall infiltration and to understand the mechanisms of slope instability, this research assumes the erosion of fine particle suspension and adopts the Worman and Olafsdottir erosion criterion to establish a coupled model of unsaturated seepage and internal erosion. The developed model simulates the coupled response of seepage and erosion in unsaturated landfill slopes under three different rainfall intensities. It is then combined with the infinite slope model to quantitatively analyze the impact of fine particle migration on soil permeability and slope stability. The numerical simulations provide the following findings: The Worman and Olafsdottir erosion criterion, unlike the Cividini and Gioda erosion criterion, only requires the determination of the soil’s gradation curve to estimate the erosion rate. Internal erosion primarily occurs within the leading edge of moisture penetration, accelerating the advancement of the wetting front and reducing slope stability. When the rainfall intensity is lower than the saturated permeability coefficient, the influence of internal erosion can be disregarded. However, under rainfall intensities equal to or greater than the saturated permeability coefficient, considering internal erosion results in a difference in the depth of the wetting front of up to 34.2 cm after 6 h in the R2 scenario. The safety factor without considering internal erosion is 1.12, whereas considering internal erosion yields safety factors between 1.08 and 1.09. In the R3 scenario, the difference in the depth of the wetting front reaches 53.8 cm after 6 h, with a safety factor of 1.12 without considering internal erosion and safety factors between 1.06 and 1.07 when considering internal erosion.

Impounded sediment and dam removal: Erosion rates and proximal downstream fate

AbstractSediment management is an important aspect of dam removal projects, often driving costs and influencing community acceptance. For dams storing uncontaminated sediments, downstream release is often the cheapest and most practical approach and can be ecologically beneficial to downstream areas deprived of sediment for years. To employ this option, project proponents must estimate the sediment quantity to be released and, if substantial, estimate how long it will take to erode, where it will go and how long it will stay there. We investigated these issues when the Bloede Dam was removed from the Patapsco River in Maryland, USA, in 2018. The dam was about 10 m high, and its impoundment was nearly filled with an estimated 186 600 m3 of sediment composed of 70% sand and 30% mud. After removal, using elevation surveys generated by traditional methods as well as structure‐from‐motion (SfM) photogrammetry at high temporal resolution, we documented rapid erosion of stored sediments in the first 6 months (~60%) followed by greatly reduced erosion rates for the next two and a half years. A stable channel developed in the impoundment during the rapid erosion phase. These results were predicted by a two‐phased erosion response model developed from observations at sand‐filled impoundments, thus expanding its applicability to include impoundments with a sand‐over‐mud stratigraphy. A similar two‐phase erosion response has been reported for sediment releases at other dam removals in the United States, France and Japan across a range of dam and watershed scales, indicating what practitioners and communities should expect in similar settings. Downstream, repeat surveys combined with discharge and sediment gaging showed rapid transport of eroded sediments through a 5‐km reach, especially during the first year when discharges were above normal, and little overbank storage.

Enhancing cavitation erosion resistance of VC+TiC coatings with PTFE in marine environments via lasso regression optimization

This research explores the mechanical properties and erosion mechanisms of SS316, VC+TiC, and PTFE coatings to study cavitation erosion resistance. Microhardness analysis revealed that VC+TiC showed the highest resilience due to its hardness, while PTFE, despite lower hardness, displayed potential with formulation adjustments. Lasso Regression models effectively predicted mass loss under various testing conditions, indicating strong relationships between independent variables and erosion responses. Scanning Electron Microscopy (SEM) analysis uncovered distinct erosion mechanisms for each coating, with SS316 showing plastic deformation, VC+TiC exhibiting crater formation, and PTFE displaying torn splats. The development of superhydrophobic surfaces from VC+TiC and PTFE coatings offers promising applications in mitigating cavitation erosion, providing valuable material-specific insights into this phenomenon.

Water Erosion Response to Rainfall Type on Typical Land Use Slopes in the Red Soil Region of Southern China

Land use and rainfall are two important factors affecting soil erosion processes. The red soil region of southern China is a representative region with high rainfall amounts and rapidly changing land use patterns where the water erosion process is sensitive to changes in land use and rainfall. To comprehensively understand the water erosion response to land use and rainfall in this region, a 6-year in situ experiment based on eight plots (bare land and seven typical land uses) was conducted from 2015 to 2020. The 320 rainfall events were divided into 4 types, and there were 3 main rainfall types. The runoff of different rainfall types was primarily determined by the rainfall amount, while the soil erosion of different rainfall types was primarily determined by the rainfall intensity. High-intensity rainfall contributed the most to both total runoff and soil erosion. Compared with bare land, the seven typical land uses reduced runoff and soil erosion by more than 75%. Grassland, cropland, and forest with low vegetation coverage experienced high runoff and soil erosion, while shrubland most effectively reduced runoff and soil erosion. The combination of land use and rainfall type significantly affected the annual average runoff depth, soil erosion modulus, and soil loss coefficient. Rainfall types can change the relationship between runoff and soil erosion for different land uses. The runoff and soil erosion of bare land were highly correlated with rainfall characteristics, while vegetation weakened this relationship under short- or moderate-duration rainfall. To effectively reduce water erosion, high-intensity rainfall should receive special attention, and all land uses should ensure that vegetation is well developed, especially understory vegetation.

Response of road erosion to hydrological connectivity under a heavy rainstorm in an agricultural watershed on the Loess Plateau

Road network extension is closely associated with soil erosion in watersheds during frequent extreme rainfall events. Identifying potential risk areas that actively deliver surface runoff to road structures and channel networks is critical for comprehending hydrological processes and controlling road erosion. In this study, the road erosion (landslides, collapses, scour pits, and gullies on monitored roads) on the Loess Plateau during a heavy rainstorm was analyzed using field survey and unmanned aerial vehicle (UAV) data. We defined hydrological connections as the intersections of roads and channel networks, and the activated hydrological connections represent hydrological connectivity. The results of this study highlight the exacerbating effect of hydrological connectivity on road erosion during a rainstorm in an agricultural watershed in the Loess Plateau region. The results showed that the road erosion intensity ranged from 2.16 × 102 to 1.02 × 104 t/ha. Strong hydrological connectivity resulted in average soil erosion amounts of landslides, collapses, scour pits, and gullies in the downslope area that were 2.16, 1.78, 5.46, and 6.98 times greater than those without hydrological connectivity, respectively. The presence of hydrological connectivity generated a 1.88 times higher road surface erosion intensity than that without hydrological connectivity. The Upslope-Road connections created the most significant enhancement effect on road erosion, and up to 65.37 % landslide erosion and 41.97 % collapse erosion amounts were influenced by these connections.The enhancement effect of Upslope–Road connections on road erosion varied with different road types, this impact of Upslope–Road connections on road erosion were only observed on the landslide erosion of petroleum transport roads and the collapse erosion of agricultural roads. Conversely, Road–Downslope connections did not significantly impact road erosion (p > 0.05). To effectively control the negative effect of road erosion, hydrological connections should be identified and regulated to impede hydrological connectivity activation during rainstorms by modifying tillage activities, improving road maintenance, and strengthening drainage systems.

Impact of watershed management practices on vegetation, land use changes, and soil erosion in River Basins of the Atlas, Morocco

Soil erosion, a land degradation process triggered by natural and anthropogenic factors, seriously impacts landscapes and water resources. The influence of vegetation cover and land use changes on intensity of soil erosion of two catchments in mountainous regions of Morocco is evident, as it alters hydrologic response and sediment dynamics. This research aims to analyze the interactions among plants, soil, geology, meteorology, and orography, assessing soil erosion responses using the process-oriented IntErO model - Erosion Potential Method to determine erosion rates. The obtained results indicate that the Tiguert river basin experiences higher soil losses (Ggod = 5184.47 m³/god) and soil losses per square kilometre (Ggod/km² = 508.28 m³/km² god) compared to the Wanmroud catchment (Ggod = 2555.66 m³/god, Ggod/km² = 381.44 m³/km² god), confirming the theory that areas with denser and more effective vegetation cover experience lower soil erosion rates. Furthermore, the Wanmroud basin exhibits a more regular shape and lower watershed development coefficient, implying lower human impact. This study has shown the relationships between land use changes, vegetation cover, and soil erosion dynamics, offering valuable insights for sustainable land management practices in mountainous regions of Morocco.

Cliff recession geodynamics variability and constraints within poorly consolidated landslide-prone coasts in the southern Baltic Sea, Poland

Abstract This study identifies the reasons for geodynamics variability of the coastal system within two cliff-shore sections of the southern Baltic Sea (SBS). The comparative analysis included distinct moraines and their foregrounds near the open sea (S1) and within the Gulf of Gdańsk (S2). Short-term trends indicate a direct link between landslide occurrence and increased cliff retreat. Long-term (total) values were obtained by developing the 4F MODEL for large-scale applications, based on the analysis of remote sensing and hydroacoustic data (to determine the extent of shore platforms), the modelling of higher-order polynomial functions describing their extent, followed by the integral calculus of the indicated functions within the open-source Desmos environment. The retreat dynamics for individual landslides (S1) was an order of magnitude higher (m/yr) than the average for the whole cliff section (0.17 ± 0.008 m/yr), which correlates well with medium- and long-term development tendencies and recession dynamics, revealed by the numerical modelling method, since approximately 8 ka b2k, years before 2000 CE (at S1 = 0.17 ± 0.020 m/yr, at S2 = 0.11 ± 0.005 m/yr). While the approach described in this paper can reveal, project, and simulate the dynamics of past and future trends within other cliffed coasts shaped in tideless conditions, it also proves stable moraine erosional responses to sea-level rise since the Mid-Holocene.

Identification and simulation the response of storm-induced coastal erosion in the China Yellow sea

Storm events have a significant impact on coastal topography, which can subsequently lead to coastal erosion and ecological deterioration. Traditional field measurements are affected by environmental factors and consume substantial resources, making it difficult to conduct large-scale terrain, hydrodynamic and other monitoring tasks. Significant challenges still remain to identify the response of coastal processes to storm events due to the lack of field measured data. In this study, the response of coastal morphodynamical variations to extreme storm events was simulated by the coupled XBeach and FVCOM models and the storm-induced coastal evolution was evaluated in the China Yellow Sea. The costal morphodynamical variations under different wind conditions were also quantified. The results reveal that erosion dominated the supratidal zone while accretion mainly occurred in the subtidal zone. Comparing the coastal morphology before and after the storm, we found the alongshore currents were the primary factors influencing sediment transport. The degree of coastal erosion and accretion shift was positively correlated with the wind speed and direction. The present nested model may serve as a valuable tool for predicting future coastal erosion and accretion, contributing to more scientifically informed coastal management decisions. The study also provides a scientific basis for understanding the response mechanism of coastal morphodynamical process to extreme storm events and coastline evolution under global change.

Response of soil erosion to vegetation and terrace changes in a small watershed on the Loess Plateau over the past 85 years

Land use on the Chinese Loess Plateau has undergone dramatic changes over the past few decades. The implementation of a series of soil and water conservation measures has significantly altered the soil erosion, transportation, and deposition processes on the Loess Plateau. To effectively address and mitigate soil erosion, it is crucial to accurately quantify the soil loss rate and analyze the contributions of soil and water conservation measures over the past several decades. In this study, the Zhifanggou watershed, located in the hilly area of the Chinese Loess Plateau, is utilized as an illustrative example. Using historical data, remote sensing imagery, and on-site data of soil, vegetation, and soil conservation measures, we assessed the soil loss rates from 1938 to 2022 based on long-term land use changes, utilizing the Chinese Soil Loss Equation (CSLE) model. Furthermore, we employed a quantitative evaluation to assess the impacts of vegetation change and terrace construction on soil erosion. The findings of our study reveal significant transformations in land use. Farmland experienced an initial increase followed by a subsequent decline, while the opposite pattern was observed for forest land. The simulated soil loss rate for the entire watershed exhibited an upward trend, rising from 34.86 t·ha−1·yr−1 in 1938 to 104.11 t·ha−1·yr−1 in 1958, before declining to 56.98 t·ha−1·yr−1 in 1999 and reaching 5.87 t·ha−1·yr−1 in 2022. Attribution analysis showed that vegetation change exerted a dominant influence on recent soil erosion dynamics, accounting for 86.10 % of the total contribution in 2022, while terraces contributed 13.90 %. These findings clarify long-term soil erosion mechanisms and provide guidance for watershed soil and water conservation management.

Complex erosional response to uplift and rock strength contrasts in transient river systems crossing an active normal fault revealed by 10Be and 26Al cosmogenic nuclide analyses

AbstractUnderstanding the influence of bedrock lithology on the catchment‐averaged erosion rates of normal fault‐bounded catchments and the effect that different bedrock erodibilties have on the evolution of transient fluvial geomorphology remain major challenges. To investigate this problem, we collected 18 samples for 10Be and 26Al cosmogenic nuclide analysis to determine catchment‐averaged erosion rates along the well‐constrained Gediz Fault system in western Türkiye, which is experiencing fault‐driven river incision owing to a linkage event ~0.8 Ma and has weak rocks overlying strong rocks in the footwall. Combined with existing cosmogenic data, we show that the background rate of erosion of the pre‐incision landscape can be constrained as &lt;92 mMyr−1, and erosion rates within the transient reach vary from 16 to 1330 mMyr−1. Erosion rates weakly scale with unit stream power, steepness index and slip rate on the bounding fault, although erosion rates are an order of magnitude lower than slip rates. However, there are no clear relationships between erosion rate and relief or catchment slope. Bedrock strength is assessed using Schmidt hammer rebound and Selby Rock Mass Strength Assessments; despite a 30‐fold difference in erodibility, there is no difference in the erosion rate between strong and weak rocks. We argue that, for the Gediz Graben, the strong lithological contrast affects the ability of the river to erode the bed, resulting in a complex erosional response to uplift along the graben boundary fault. Weak covariant trends between erosion rates and various topographic factors potentially result from incomplete sediment mixing or pre‐existing topographic inheritance. These findings indicate that the erosional response to uplift along an active normal fault is a complex response to multiple drivers that vary spatially and temporally.

Hillslope and vegetation response to postglacial warming at Bear Meadows Bog, Pennsylvania, USA

AbstractConnecting changes in erosion and vegetation is necessary for predicting topographic and ecologic change in thawing permafrost landscapes. Formerly periglacial landscapes serve as potential analogs for understanding modern permafrost landscape change, yet compared to paleoenvironmental records at these sites, less is known about concurrent geomorphic processes, particularly their rates and relationships to climate change. Here, we target sediments preserved in a central Appalachian peat bog to reconstruct sedimentation across the last deglacial warming. We use ground-penetrating radar and geochemistry of cored bog sediments to quantify sedimentation timing, style, and provenance. Using 14C dating of sedimentary and geochemical shifts, we connect depositional changes to global climate and local vegetation change. We show that deglacial warming promoted deep soil disturbances via solifluction at ca. 14 ka. In contrast, relatively wetter conditions from ca. 10–9 ka promoted shallow disturbance of hillslopes via slopewash, which corresponds to a time of vegetation change. Our results highlight climate-modulated erosion depth and processes in periglacial and post-periglacial landscapes. The existence of similar erosion and vegetation records preserved regionally implies these dynamics were pervasive across unglaciated Appalachian highlands, aiding in reconstructing erosion responses to warming at a resolution with implications for predicting high-latitude landscape responses to disturbance.

Erosion Mechanisms in Unpaved Roads: Effects of Slope, Rainfall, and Soil type

Erosion is the main cause of damage to unpaved roads. This study utilized rainfall simulators to quantify erosion on unpaved roads, controlling variables such as rainfall intensity and slope. A laboratory model of an unpaved road was utilized to evaluate soil loss in an experimental setup. A total of 72 tests were conducted to compare simulated conditions on unpaved roads for three soil types with three slope variations, and eight rainfall intensities. The impact of each variable (soil type, slope, and rainfall intensity) on soil loss was analyzed for 30-minute rainfall events. Analysis of variance (ANOVA) was employed to assess soil erosion response to terrain slope for the three soil types, revealing statistical differences in soil loss between low slopes (2%) and steep slopes (7%) with p-values of .04 (sandy soil), .00007 (sandy silt soil), and .00008 (loam silt soil). Correlation analysis demonstrated a strong relationship between rainfall intensity and soil loss ( R2 = .76) for sandy soil and sandy silt soil. Analysis of covariance (ANCOVA) indicated a linear relationship between soil loss and rainfall intensity, with significant differences ( p &lt; .05). The findings suggest that soil loss on unpaved roads is positively correlated with slope and rainfall intensity. However, this relationship is not always linear; sandy soil exhibited a nonlinear relationship, especially with high rainfall intensities, whereas sandy silt soil showed a linear relationship with evaluated rain intensities. The type of soil influences erosion process, with higher erosion rates observed in sandy silt soils compared to loam silt soils. This paper analyzed the factors essential for addressing erosion on unpaved roads, identifying key elements to minimize soil loss.

Satellite observations of storm erosion and recovery of the Ebro Delta coastline, NE Spain

Storms and extremely energetic events may significantly impact the form and structure of beaches, and so cause erosive processes and coastal damages. Efficient management actions require an up-to-date and accurate knowledge of beach morphological changes, with the shoreline position being a good indicator of such changes. This work proposes the use of the open-source Shoreline Analysis and Extraction Tool (SAET) software for the definition of satellite-derived shorelines (SDSs) from L8 and Sentinel-2 imagery to reveal the shoreline position changes at the beaches of the Ebro Delta, NE Spain. Spatial-temporal models (STMs) of shoreline changes enable a characterisation of how the beaches responded to the storms of 2020. In conjunction with wave data, STMs enable an analysis of the erosive response to storm events, as well as a monitoring of subsequent beach recovery in the short and medium term (<1 year). Results show how Storm Gloria (January 2020, Hs max = 7.62 m) acted as a disruptive event and shifting point in the shoreline trend. As a response to that storm, major erosive processes occurred along the delta that caused an average shoreline retreat of 47 m. A progressive recovery during the spring and summer was mainly associated with periods of low wave energy. Nevertheless, by the end of the year a complete recovery had been achieved for about half of the coast, while the other half showed an average erosion of more than 10 m when compared to the pre-storm situation. Both the erosive and the recovery processes took place unevenly on different sections of the coast, probably dependent on factors such as the orientation of the beach and the pattern of longitudinal sediment transport along the coast.

Response of soil erosion to climate change and vegetation restoration in the Ganjiang River Basin, China

In the context of global warming it remains challenging to evaluate declining of soil erosion due to ecological engineering measures, and to isolate and quantify the contributions of various factors involved in soil erosion. For this study, soil erosion and soil conservation dynamics in the Ganjiang River Basin (GRB) in southeast China were quantitatively assessed based on the Integrated Ecosystem Services and Tradeoff Assessment (InVEST) model. Based on the analysis of the attribution factors of precipitation and Fractional Vegetation Cover (FVC), the dominant factors involved in soil erosion were determined by scenario comparison, where the areas with high sensitivity to erosion were quantitatively identified. The results revealed that both simulated value of soil erosion and sediment export initially decreased and then increased from 2000 to 2020; however, the total increases over the last 20 years were 14 % and 18.18 %, respectively. Moreover, the erosion intensity and sediment delivery ratio (SDR) decreased due to the influence of engineering measures such as reservoirs. Precipitation was the dominant factor that affected GRB soil erosion, with its contribution ratio (40 %-60 %) being as high as 94.74 %. In other words, in the GRB, precipitation inhibited the mitigation effect of high vegetation cover on soil erosion, and the contributions of FVC and precipitation showed a vertical trend. The extremely sensitive area caused by FVC is situated in the economically developed cities along the river system in the middle portion of the basin, while the extremely sensitive area caused by precipitation resides in the middle and upper reaches of the western portion of the basin. Based on this, prioritized protection areas can be determined.