Erosion Research Articles

Why do people live in disaster-prone char regions? Perspectives from Assam, India

People residing in the char regions of Assam are among the most vulnerable in the state, and particularly susceptible to multiple disasters such as floods, storms, and land erosion. Despite the existing vulnerabilities and widespread poverty, people continue to live in these areas. Our research aims to investigate why people continue to reside in these areas in such conditions and explore the feasibility of relocation as a possible solution to catastrophe risk mitigation, considering people's perceptions of living in these locations. This study uses a mixed method’s approach to achieve its objectives, based on primary data, collected through a household survey and focus group discussions. A total of 394 char residents from four districts of Assam participated in data collection. The Contingent Valuation Method (CVM) has been applied to understand residents' living preferences. Additionally, we used regression models to determine the factors influencing char residents' preference for living in these vulnerable areas. Our findings reveal that while most people prefer to live in the char areas, the risks of multiple disasters are driving some to consider leaving, exacerbated by infrastructure bottlenecks. However, char dwellers do not view relocation as a desirable solution. Alternatively, improving infrastructure and reducing disaster risks could lead to higher-levels of development and satisfaction for char residents.

Assessing the Global Sensitivity of RUSLE Factors: A Case Study of Southern Bahia, Brazil

Global sensitivity analysis (GSA) of the revised universal soil loss equation (RUSLE) factors is in its infancy but is crucial to rank the importance of each factor in terms of its non-linear impact on the soil erosion rate. Hence, the goal of this study was to perform a GSA of each factor of RUSLE for a soil erosion assessment in southern Bahia, Brazil. To meet this goal, three non-linear topographic factor (LS factor) equations alternately implemented in RUSLE, coupled with geographic information system (GIS) software and a variogram analysis of the response surfaces (VARSs), were used. The results showed that the average soil erosion rate in the Pardo River basin was 25.02 t/ha/yr. In addition, the GSA analysis showed that the slope angle which is associated with the LS factor was the most sensitive parameter, followed by the cover management factor (C factor) and the support practices factor (P factor) (CP factors), the specific catchment area (SCA), the sheet erosion (m), the erodibility factor (K factor), the rill (n), and the erosivity factor (R factor). The novelty of this work is that the values of parameters m and n of the LS factor can substantially affect this factor and, thus, the soil loss estimation.

Use of Geomatic Techniques for Mapping Suspended Solids in Aquatic Ecosystems: The Case Study of Guayas River, Ecuador

Satellite images cover large remote areas and are useful for detecting and monitoring water bodies. In Ecuador, since 1950, the lower Guayas River basin has undergone significant natural and anthropogenic changes that have impacted its dynamics and sustainability. This study aims to analyze through in situ data and geomatic techniques the change that the river has undergone in a decade by mapping the Suspended Sediment Concentration (SSC). Increasing levels of pollution in the river have raised concerns, prompting various approaches to measure and mitigate sedimentation to maintain the sustainable quality of the watershed. The spatiotemporal variations of SSC in the Guayas River revealed a remarkable variability, influenced by the operation of reservoirs, changes in land use, erosion, and sedimentation causing SSC in 2013 to range from 64.82 to 707.06 mg/l in the satellite image of 9/16/2013 and from 87.58 to 933.36 mg/l in the image of 7/26/2023. Understanding this distribution is crucial for the environmental protection and sustainability of aquatic ecosystems. This study used Landsat 8 data, an atmospheric pre-correction, and a remote sensing model. The results indicate a creasing trend of SSC in the stretches of the Guayas River between 2013 and 2023, which allows the understanding of the spatiotemporal dynamics of suspended sediment transport.

Effect of bedrock permeability on runoff and soil loss in soil-mantled karst slopes under successive rainfall conditions

Soil-mantled karst slopes exhibit rapid surface-belowground hydrological responses to rainfall because thin soil layers cover the bedrock. Bedrock features may play important roles in surface-belowground hydrological processes; however, the underlying mechanisms remain unclear. Herein, the effects of impermeable (no fissures) and permeable (3 % fissure rate) bedrock (BS1 and BS2, respectively) on the surface and belowground runoff and soil loss processes were investigated during three successive rainfall events. During each event, the surface runoff (SR), subsurface runoff (SBR), soil–rock interface flow (SRIF) and bedrock fissure permeation flow (BFPF) were recorded. The results showed that the SR and SBR rates for the BS1 slope were significantly greater than those for the BS2 slope (P < 0.05) under all rainfall events. During rainfall, the SR and SBR accounted for ∼ 19 % and 8 %-12 % of the rainwater on the BS1 slope, respectively, and both were less than 5 % of the rainwater on the BS2 slope. Approximately 40 %-55 % of the rainwater was partitioned into SRIF on BS1 slope, and 54 %-74 % of the rainwater was partitioned into the BFPF on the BS2 slope. Furthermore, the BFPF on the BS2 slope was 33 % greater than the SRIF on the BS1 slope at the 1st rainfall and it increased to 50 % at the 3rd rainfall, suggesting that the successive rainfall increased the difference in rainwater loss from the bedrock surfaces between the slopes with different permeabilities. The surface soil loss rate was very low (< 0.01 g·m2·s−1) due to the low SR, and a significant positive correlation was found between the SR rate and surface soil loss rate (P < 0.01) for both slopes. Compared with that on the BS2 slope, the soil loss on the BS1 slope was greater because of the higher SR rate. The belowground soil loss curves were discontinuous, indicating that the belowground soil loss process was very different from the surface soil loss. Therefore, bedrock permeability has a strong influence on runoff and soil loss in soil-mantled karst slopes, and this effect further increases with successive rainfall events.

Photovoltaic Soiling Loss in Europe: Geographical Distribution and Cleaning Recommendations

Despite being one of the major issues that photovoltaic systems face worldwide, estimating the energy and economic magnitude of soiling of solar collectors still represents a challenge. This work presents a first European assessment of the soiling loss and of the cost-effectiveness of soiling mitigation. New soiling maps are generated through the interpolation of reanalysis data, calibrated against ground-measured losses from sensors installed across the continent. The results show that Europe experiences an average annual soiling loss of 0.9% if rain is considered a perfect cleaning agent. However, if a cleaning effectivity by rain of 10% is assumed, this annual loss increases up to 5.3%. In some southern locations, soiling losses are markedly seasonal, while these are more consistent in central Europe. These losses can have repercussions on the economics of photovoltaics, increasing the levelized cost of electricity up to 4% or 15% depending on the cleaning effectivity of rain. The losses are also found to vary significantly in some sites from year to year, highlighting the need for continuous monitoring. The study concludes that implementing adequate soiling mitigation measures is strongly recommended in most of the regions due to the high electricity prices and the comparatively low cleaning costs.

The effect of surface flow conditions on WEPP interrill erodibilities

The Water Erosion Prediction Project erosion model (WEPP) was developed as an event-based more process-based replacement for Universal Soil Loss Equation (USLE) based models in predicting soil erosion as a guide to conserving soil in the USA. However, WEPP has not been shown to predict event soil losses for bare fallow USLE plots better than USLE-based models when stipulated input values have been used. To some extent, this problem can be attributed to the availability of more refined and site-specific input parameters for the USLE-based models. This is true with respect to WEPP’s capacity to model raindrop-driven erosion on USLE plots under natural rainfall. Stipulated values for WEPP interrill erodibilities in the USA were determined only for ridge side slopes but USLE-based models focus on the prediction of long-term average annual soil loss caused by both sheet and rill erosion on planar surfaces. The interrill erodibilities determined for ridge side slopes did not correlate well with those on adjacent flat surfaces sloping along the land slope under the same rainfall conditions. Surface flow conditions, particularly flow depth, differ between the short high gradient side slopes associated with ridges, and the lower gradient slopes in interrill and sheet erosion areas on USLE plots. Failure of WEPP to account for the influence of different flow conditions between ridged and flat areas on raindrop-driven erosion affects the veracity of WEPP to predict average annual soil loss on USLE plots under natural rainfall and the use of WEPP to act as a replacement for USLE based models as an aid to make land management decisions to conserver soil in the USA.

Evolution of mechanical behavior in granular soil during fine particle loss simulated by salt dissolution: Insights from ring shear tests

Fine particle loss in soil is one of the main causes of slope instability and geotechnical structure failure. Loss of fines can cause instability in granular assembles by changing the fabric and microstructure of the sample. However, real-time monitoring of the evolution of mechanical behavior in granular soils during the particle loss process is still poorly explored. This study presents a novel approach by simulating fine particle loss through salt dissolution in ring-shear tests, offering real-time insights into the mechanical evolution of granular soils under realistic stress conditions. Meanwhile, the shear resistance, shear displacement, vertical displacement, salt content, and acoustic emissions were simultaneously recorded. The test results showed that the instability of the sample was triggered by the loss of fine particles. With a gradual loss of fine particles, both the vertical and shear deformations and the void ratio increased. The evolution of shear resistance in the sample can be divided into three stages: stress weakening, then strengthening, and finally recovery to the initial value. We infer that the evolution of shear resistance originated from the collapse and rearrangement of its granular fabric and microstructure. Additional evidence for this hypothesis was provided by high-frequency acoustic emissions (approximately 150 kHz), suggesting buckling of the force chains accompanying the particle loss process. Furthermore, the sample experienced greater shear deformations and stress weakening that developed under a larger initial fine content or a higher normal stress. This finding may provide valuable insights into the mechanical behavior of granular soil during the fine particle loss process.

Evaluation of adaptive capacity of slope regulation and storage measures on the Loess Plateau under drought stress

The study evaluated the adaptive ability of slope regulation and storage measures (SRASM) under drought stress, providing scientific basis for improving water resource management and ecological protection in the arid environment of the Loess Plateau region. Four SRASM including afforestation on the hilltop (forestland engineering), returning farmland to forest on the hillside (grassland engineering), building terraces on the hillside (terraced fields engineering) and damming and silting on the valley floor (silting dam engineering) can effectively solve the problem of water and soil loss on the Loess Plateau. However, it is still unclear how the adaptive capacity (resistance and resilience) of these SRASM under drought stress. This study took the above four SRASM as the study object, used the performance of the four SRASM after drought and rehydration events as the basis for judging the adaptive capacity under drought stress. It proposed evaluation methods for drought and rehydration events, as well as calculation methods for resistance and resilience. Furthermore, it analyzed the adaptive capacity of different SRASM and different sub-basins in the middle reaches of the Yellow River under drought stress, as well as the impact of slope on adaptive capacity. The results showed that when light and moderate drought occurred, four SRASM recovered to their normal state after rehydration. In terms of resilience, forestland engineering > grassland engineering > terraced fields engineering > silting dam engineering, and grassland engineering had the most prominent ability to resist drought. As the slope increased, the adaptive capacity decreased. From a spatial perspective, the resilience in the western part of the middle reaches of the Yellow River was lower than that in the eastern, and the spatial distribution of resistance in the middle reaches of the Yellow River generally decreased from northwest to southeast.

Biobased hydrophobic liquid mulch film from soybean oil and starch for enhanced terraced field cultivation.

Terraced agriculture faces soil loss during rainstorms leading to natural disasters and crop growth impediments. This study describes a novel biobased hydrophobic liquid mulch film comprised of waste soybean oil, starch, and acrylate monomers that can be used to enhance terraced field cultivation. The novel film, optimized at a 3:7 soybean oil to acrylate monomers ratio, exhibited superior spray ability, reduced wicking, and excellent film formation, which are crucial for its effectiveness as a water erosion barrier. The wet state of the SOSA film demonstrated optimal impact resistance, with increased elongation at break and reduced breaking strength compared to its dry state, facilitating seedling emergence. It significantly improved soil moisture retention (4.8-5.7 %) and temperature (0.9-5.6 °C) and boosted maize seed germination by 28 %. Under extreme conditions of a 24° slope and 90 mm/h rainfall, the SOSA film achieved an 80.6 % reduction in soil loss and a 57.4 % increase in pakchoi yield over bare soil. This study's comprehensive analyses confirmed the film's formation mechanism and provided a scientific basis for its practical application performance, highlighting the film's unprecedented success in using waste materials for sustainable terrace farming and its potential as a transformative approach to soil conservation and crop productivity.

Morphological changes of river Bank Erosion and channel shifting assessment on Arial Khan River of Bangladesh using Landsat satellite time series images

The continuous processes of erosion and deposition in rivers are intricately linked to changes in land use and land cover (LULC), reflecting dynamic landscape transformations. This study investigates the rate of riverbank erosion, channel shifting, and the impact of erosion on LULC dynamics along the Arial Khan River. Utilizing GIS and remote sensing techniques, we analyzed time-series satellite images from 1993 to 2024 within a 2 km buffer zone of the floodplain. Supervised classification methods were applied for LULC analysis, with results validated using confusion matrices to assess classification accuracy. ArcGIS 10.8 was employed to analyze channel centerline migration, while NDVI analysis assessed vegetation health. The study reveals that between 1993 and 2024, 5142.60 ha were lost to erosion, while deposition affected 4756.52 ha, with erosion surpassing deposition overall. The river shifted an average of 0.66 km during this period, with higher migration rates in Muladi Upazila compared to Babuganj Upazila. Settlement areas expanded significantly from 137.82 ha in 1993 to 2768.68 ha in 2024, while agricultural land declined substantially. These findings provide valuable insights for policymakers to address erosion severity in confluence zones and lay the groundwork for sustainable land management practices.

Model test study on the rainfall erosion mechanisms and reclamation potential of open-pit coal mine dump soil improved by fly ash and polyacrylamide

Increasing the soil erosion resistance is one of the core issues in slope erosion control and ecological environmental restoration of open-pit coal mine (OPCM) dumps. In this study, fly ash (FA) and polyacrylamide (PAM) were used to improve the soil quality of an OPCM dump, and an indoor physical model was constructed to investigate the water and soil loss characteristics of the improved soil via simulated rainfall experiments. Scanning electron microscopy and Pore and Crack Analysis System software were employed to systematically investigate the erosion resistance mechanisms of the improved soil qualitatively and quantitatively. Finally, the improved technique for order preference by similarity to an ideal solution (TOPSIS) method was adopted to evaluate the reclamation potential of the improved soil. The results revealed that under the action of PAM (PAM and PAM–FA), the average erosion rate of the slope decreased by more than 90 %. Compared with that in the control group, when FA was applied alone, the slope erosion rate first decreased and then increased with increasing FA content. Upon PAM addition, the erosion pattern changed from the splash erosion stage, cave erosion stage, gully erosion stage, and tensile slip stage to the splash erosion stage and cave erosion stage. However, no obvious change in the runoff pattern. Erosion and runoff patterns are generally affected by the amendment type, addition concentration, porosity, pore shape, pore direction and hydrological environment. The erosion resistance mechanism of the improved soil entailed the formation of more stable soil aggregates via filling, cementation, skeleton support generation, and flocculation of FA and PAM. In addition, the optimal soil improvement was achieved when FA and PAM were added at levels of 16 % and 0.01 %, respectively. The obtained research results could be used for erosion control and ecological environmental protection of coarse-grained soil slopes in mining areas, highways and other fields and could be widely applied.

Integration of GIS with RUSLE to estimate soil, organic matter and nutrient loss from a watershed of eastern Himalayan Terai

Integration of GIS with RUSLE to estimate soil, organic matter and nutrient loss from a watershed of eastern Himalayan Terai

Highly Performing Polysaccharide Hydrogels can Replace Acrylic Acid‐Based Superabsorbent Polymers in Sanitary Napkins

AbstractSuper absorbent polymers (SAPs) used in sanitary napkin are not required for water absorption capacity as high as in baby diapers and adult incontinence pads. Sanitary napkins must absorb menses, which is delivered at a significantly lower rate and overall daily amount than urines. Thus, the acrylic acid (AA) component can not be strictly necessary. By proper formulation design and processing, polysaccharide SAPs can be equally or even better performing than AA‐containing SAPs in sanitary napkins. Fully biodegradable sodium alginate (SA)‐based SAPs are prepared through ionic cross‐linking by CaCl2 and introduced in female pads. The optimal solution concentrations (SA 8% w/v, CaCl2 0.25% w/v in water) and reaction time are identified, and addition of cellulose nanocrystals (CNC) at different weight contents (0–3 w%) is tested. Morphology, physico‐chemical properties, rheology, free swelling capacity (FSC), centrifuge retention capacity, and weight loss in soil are assessed. Increasing CNC content decreases FSC. Rheology results demonstrate higher storage and loss moduli for SA‐based SAPs versus commercial SAPs. The superior SA‐SAP developed is used in varying amounts for manufacturing sanitary napkin prototypes, revealing that excellent menstrual fluid absorption, surpassing commercial pads. Replacing AA‐based with polysaccharide‐based SAPs would reduce the environmental impact of hygienic product waste.

Effects of Land Use Land Cover Change on Gully Development in Lugari Sub Catchment, Kakamega County in Kenya

Effects of Land Use Land Cover Change on Gully Development in Lugari Sub Catchment, Kakamega County in Kenya

Soil erosion projection and response to changed climate and land use and land cover on the Loess Plateau

The Grain for Green Project has profoundly altered land use and Land cover (LULC), climate, and soil loss rates on the Loess Plateau over the past few decades. Evaluation and projection of soil erosion with the impacts of climate and LULC are essential for soil erosion control. This study focuses on the Jiuyuangou watershed (JYG), a typical representative of the climate and geographical characteristics of the Loess Plateau. Utilizing the Coupled Model Intercomparison Project Phase 6 (CMIP6) and environmental data, the Revised Universal Soil Loss Equation (RUSLE) coupled with the Future land use simulation (FLUS) model was used to assess soil loss rates for historical periods and various future scenarios. Furthermore, the qualitative and quantitative analysis methods were explored to evaluate the impacts of LULC and climate change on soil erosion. The forest and grass in the JYG increased from 33.4 % in 1995 to 74.1 % in 2020. The soil loss rate significantly decreased, from 64.95 t ha−1·yr−1 in 1995–4.52 t ha−1·yr−1 in 2020. The trend of converting cropland to forest and grass is predicted to continue under different future scenarios. The soil erosion will increase from 2030 to 2050 for different scenarios compared to 2020. The LULC development scenario aiming at ecological protection will effectively curb the increase in soil erosion compared with other scenarios. LULC exerted its influence in various forms across different historical phases. Attribution analysis indicated that the construction of check dams effectively reduced soil erosion from 1995 to 2005, while afforestation from 2005 to 2020 accounted for 64.6 % of the overall contribution. The increase in soil erosion is primarily attributed to more erosive rainfall events and unreasonable allocation of LULC. The correlation between LULC and soil erosion will decrease compared to climate. These findings elucidate the long-term mechanisms of soil erosion changes, emphasizing the urgency of sustainable practices to mitigate soil erosion in the face of environmental challenges.

Assessment of Soil Loss Due to Wind Erosion and Dust Deposition: Implications for Sustainable Management in Arid Regions

Assessment of Soil Loss Due to Wind Erosion and Dust Deposition: Implications for Sustainable Management in Arid Regions

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 &gt; 0.98) for a precipitation with given depth and intensity.

Characteristics and driving factors of spatiotemporal changes in soil erosion in the karst plateau mountainous region over 20 years.

Soil erosion is one of the main issues that endangers global ecosystems. This study explored the spatiotemporal distribution of soil erosion and its drivers in the karst plateau mountainous region. A detailed examination of topography, soil, vegetation, land use, and precipitation data from 2000 to 2020 was conducted in Bijie City using the revised universal soil loss equation model. We also explored the driving forces using a geographical detector. The findings show that between 2000 and 2020, soil erosion first decreased, followed by an increase. The southwest, south, and northern regions contained the highest intensity of soil erosion. Land use, slope, and precipitation are the primary factors influencing soil erosion, with slopes having the greatest impact. By improving our understanding of the dynamics of soil erosion and the primary variables that influence it in karst plateau mountainous environments, our findings can assist in the development of strategies and technical support for sustainable soil and water conservation.

Spatio-Temporal Changes in Erosion-Accumulation Processes on a Small Watershed in the Northern Part of the Central Russian Upland

First time comprehensive studies of soil erosion were carried out in a 42-hectare catchment area (near the Lomovets, Orel region) in the zone of Luvic Phaeozems with erosion resistance is significantly lower than that of Chernozems. Analysis of archival and historical cartographic materials showed that the duration of plowing of the catchment is 200 ± 10 years. The rates of soil erosion and accumulation over the entire plowing period, post Chernobyl period, last 50 ± 25 years and single erosion event (which occurred on May 31, 2022) were determined based on the use of field methods (soil-morphological, radiocesium, rain rills method, detailed survey using drone) and WaTEM/SEDEM erosion model calculation. The estimates of soil losses and accumulation indicate significant fluctuations in the rates of erosion-accumulative processes over the past 200 years, which are mainly due to the conditions of the formation of melt runoff, the repeatability and distribution of runoff-forming heavy rain within the warm season, the set of crops sown, the frequency and methods of tillage, changes in field boundaries. The average annual estimates of soil erosion for the agricultural period are higher than those for the post-Chernobyl period, since the rates of soil erosion have decreased in the last three decades. Estimates of soil losses using the WaTEM/SEDEM model are generally comparable with the results of determining soil losses based on the soil-morphological method, provided that the redistribution of sediment to the lower boundaries of arable land is taken into account. The spatial structure of a single erosive event turned out to be largely close to the spatial structure of the location of the areas of eroded and aggradational soils formed during the entire agricultural period.

Multi-Temporal Assessment of Soil Erosion After a Wildfire in Tuscany (Central Italy) Using Google Earth Engine

The Massarosa wildfire, which occurred in July 2022 in Northwestern Tuscany (Italy), burned over 800 hectares, leading to significant environmental and geomorphological issues, including an increase in soil erosion rates. This study applied the Revised Universal Soil Loss Equation (RUSLE) model to estimate soil erosion rates with a multi-temporal approach, investigating three main scenarios: before, immediately after, and one-year post-fire. All the analyses were carried out using the Google Earth Engine (GEE) platform with free-access geospatial data and satellite images in order to exploit the cloud computing potentialities. The results indicate a differentiated impact of the fire across the study area, whereby the central parts suffered the highest damages, both in terms of fire-related RUSLE factors and soil loss rates. A sharp increase in erosion rates immediately after the fire was detected, with an increase in maximum soil loss rate from 0.11 ton × ha−1 × yr−1 to 1.29 ton × ha−1 × yr−1, exceeding the precautionary threshold for sustainable soil erosion. In contrast, in the mid-term analysis, the maximum soil loss rate decreased to 0.74 ton × ha−1 × yr−1, although the behavior of the fire-related factors caused an increase in soil erosion variability. The results suggest the need to plan mitigation strategies towards reducing soil erodibility, directly and indirectly, with a continuous monitoring of erosion rates and the application of machine learning algorithms to thoroughly understand the relationships between variables.