Water Soil Erosion Research Articles

Farmland Degradation in the Czech Republic: Drivers and Barriers of Mitigation Strategies in Agricultural Soils

ABSTRACTIn line with Sustainable Development Goal (SDG) 15.3, which aims to restore degraded land and soil, and the priorities of the Common Agriculture Policy (CAP) to mitigate environmental issues caused by intensive agriculture, understanding the factors influencing farmers' adoption of soil conservation practices (SCPs) is crucial. However, there is still a limited understanding of these specific factors, particularly in the context of the Czech Republic. This study investigates the perceptions and determinants influencing the adoption of SCPs among farmers in the Czech Republic. We analyzed 358 randomly selected farm households using probit and multivariate probit models. Our results show that a significant number of farmers perceive soil degradation as an important problem, attributing it to factors such as low soil nutrient content, declining soil humus, water and wind erosion. The results of our analysis showed positive associations for perceived effectiveness and profitability, indicating that farmers tend to adopt practices such as minimum tillage, mulching, mixed cropping, cover cropping, and continuous soil cover when these methods are perceived to be effective and profitable. Conversely, negative associations are found for perceptions of soil degradation and education, suggesting potential barriers to adoption with higher levels of perceived soil degradation and education. The study also highlights the complex interplay of information sources on adoption, with both positive and negative trends. In light of these findings, we propose recommendations, including that awareness campaigns should be tailored to address perceptions of soil degradation, and that the use of peer networks and information dissemination from research institutions can bridge the gap between scientific recommendations and on‐farm practices. Policy makers and agricultural extension services should work together to develop targeted strategies that take into account regional differences in the factors influencing adoption and ultimately promote widespread adoption of SCPs.

Analysis of Soil Water Erosion Risk Using Machine Learning Techniques – A Case Study of Ourika Watershed in Morocco

Analysis of Soil Water Erosion Risk Using Machine Learning Techniques – A Case Study of Ourika Watershed in Morocco

Soil Erosion Analysis with GIS: A Case Study of Oued Sly Catchment, Northern Algeria

Soil erosion is a process that involves the detachment and transportation of soil particles by water, presenting notable challenges of the depletion of soil fertility, diminished agricultural productivity, and consequences for water reservoirs. The integration of Geographic Information System (GIS) and modeling techniques provides a valuable platform for assessing and addressing soil water erosion. This study specifically examines the risk of soil water erosion in the Oued Sly catchment within the Middle Cheliff watershed in northern Algeria. Employing the Universal Soil Loss Equation (USLE) and thematic maps, the research evaluates the key factors influencing erosion. Results reveal that the catchment generally experiences low to moderate erosion levels, averaging 23.4 to 40 t ha-1 yr-1 across 90.7% of the total area. However, around 9.3% of the catchment exhibits higher erosion rates exceeding 40 t ha-1 yr-1. These findings offer valuable insights for informed watershed management and strategies to mitigate soil water erosion in comparable regions

Soil, water and p losses by water erosion in soil treated with pig slurry

Pig slurry (PS) can modify the soil fertility and influence the water erosion. The aim of this research was to evaluate the effect of PS doses on the content phosphorus (P) in the soil and on water (WL) and P losses due to water erosion, in a Alfisol in southern Brazil. The treatments, totaling 0, 250, 500, and 1000 m3 ha-1 of PS applied in oats (Avena strigosa), corn (Zea mays), turnip (Raphanus sativus L.) and soybean (Glycine max), and in oat residues. Simulated rainfall (65 mm h-1 and 75 minutes) was applied three times (test -T) on corn and four T on turnip, soybean, and residues, with a simulator rotating-boom. T1 occurred one day after the application of the PS and the interval between the other T ranged from 14 to 70 days. The P in the soil was determined before and after the survey. During runoff, runoff samples were collected to determine WL and P in the water. The PS did not influence the P in the soil. The P in runoff water was 78% higher in the D1000 treatment than in D0, while the difference in total P loss was 90%. Soil P at the end of the research increased at the beginning of the research, and the content in the soil at the end of the research decreased with increasing layer depth. P loss increased with increasing water loss, while P in water increased with increasing P in the soil.

Using USLE, GIS and remote sensing for the soil loss assessment in the National Park of Theniet El Had, Algeria

Soil water erosion is one of the problems that affect the environment, agriculture and social life by threatening several land surfaces. The objective of this study is to use the USLE model, GIS and remote sensing (RS) to estimate the annual rate of soil loss by water erosion in the Theniet El Had National Park (THNP) which belongs to the mountainous ecosystem of Djebel El Meddad, located in the northwest of Algeria. The use of the USLE model takes into account the five factors controlling water erosion, namely: the rain erosivity (R) determined from the annual rainfall data, the soil erodibility (K) developed from soil survey data, the slope lengths (LS) generated by using DEM, the vegetation cover (C) by the use of RS data and erosion control management practices (P) by field trips. The integration of these factors made it possible to establish the quantitative map of the annual rate of soil loss varying between 0.02 and 55.10 (t/ha.year), with an average of around 6.64 (t/ha.year). Five erosion aggressiveness classes are used; very weak, weak, moderate, strong and very strong which represent a rate respectively of 23.70, 44.65, 22.72, 4.41 and 4.52 % of the study area surface. The areas with high and very high erosion rates are located in the north having a very rugged relief and low vegetation cover. This study can be used in the mountainous ecosystems and it will make it possible to set up priority intervention zones to combat the risk of water erosion.

Development of Interpolyelectrolyte Complex Based on Chitosan and Carboxymethylcellulose for Stabilizing Sandy Soil and Stimulating Vegetation of Scots Pine (Pinus sylvestris L.).

The issue of water and wind erosion of soil remains critically important. Polymeric materials offer a promising solution to this problem. In this study, we prepared and applied an interpolyelectrolyte complex (IPEC) composed of the biopolymers chitosan and sodium carboxymethyl cellulose (Na-CMC) for the structuring of forest sandy soils and the enhancement of the pre-sowing treatment of Scots pine (Pinus sylvestris L.) seeds. A nonstoichiometric IPEC [Chitosan]:[Na-CMC] = [3:7] was synthesized, and its composition was determined using gravimetry, turbidimetry, and rheoviscosimetry methods. Soil surface treatment with IPEC involved the sequential application of a chitosan polycation (0.006% w/w) and Na-CMC polyanion (0.02% w/w) relative to the air-dry soil weight. The prepared IPEC increased soil moisture by 77%, extended water retention time by sixfold, doubled the content of agronomically valuable soil fractions > 0.25 mm, enhanced soil resistance to water erosion by 64% and wind erosion by 81%, and improved the mechanical strength of the soil-polymer crust by 17.5 times. Additionally, IPEC application resulted in slight increases in the content of humus, mobile potassium, mobile phosphorus, ammonium nitrogen, and mineral salts in the soil while maintaining soil solution pH stability and significantly increasing nitrate nitrogen levels. The novel application technologies of biopolymers and IPEC led to a 16-25% improvement in Scots pine seed germination and seedling growth metrics.

Soil hydro-physical variables and crop residues determinate runoff, soil loss, and glyphosate and AMPA concentration in the aqueous phase under simulated rainfall events.

Soil structural degradation and water erosion processes were observed even in no-tillage schemes in the Pampas region. Within these conservation systems, agrochemical application per hectare is one of the highest globally. Thus, this entails a serious risk of water contamination. The objectives of this study were to (1) test the hypothesis that the hydrological dynamics and sediment concentration related to surface runoff were conditioned by soil structure regardless of the presence of maize (Zea mays L.) crop residue and (2) assess the incidence of maize crop residue on glyphosate and aminomethylphosphonic acid (AMPA) concentration in runoff. The soil under study corresponded to Arroyo Dulce Series (Typic Argiudoll silty loam soil). Rain simulations were performed in the laboratory on undisturbed soil samples. Total runoff and infiltration rate were similar between treatments with C(+) and without C(-) maize crop residues (C(+) 1381.40mL and 14.27mm h-1, C(-): 1529.70mL and 21.67mm h-1). The C(-) treatments showed a higher sediment concentration than C(+) (1.58 and 0.42g 100mL-1, respectively). Glyphosate and AMPA average values in runoff were 15.9 and 33.9µg L-1. High variability of the hydro-physical properties and occurrence of soil structure, particularly platy ones, were detected. The hydrological variables were conditioned mainly by the occurrence of platy structures regardless of crop residue presence. Glyphosate concentration was increased in the first runoff event by the presence of corn residues, while AMPA concentrations were higher in the second runoff event in both residue treatments. In this study, maize residue on the soil surface protected the soil from sediment detachment but did not change runoff or infiltration. Thus, the implementation of agricultural management practices that promote vegetative residue cover has shown positive results to erosion.

CONTRIBUTION TO THE STUDY OF SOIL VULNERABILITY TO WATER EROSION IN THE THIES PLATEAU

This study was carried out in the watershed located between the municipalities of Tassette and Notto, where soil water erosion is one of the most dangerous threats in the region.This work aims to quantify the degree of soil erodibility in the Thiesplateauand then draw up an erosion risk map using the improved boyoucoss method. Interpretation of the experimental results reveals that the erodibility index varies between 1.62 and 14.10, with an average value of 5.6. This variation in the erodibility index shows areas of high, moderate and very high vulnerability, respectively 59%, 18.2% and 18% of the areas studied. The progressive degradation of soils by water erosion is also amplified by inappropriate human activities, weakening the resilience of ecosystems and communities.

Modelling, quantification and estimation of the soil water erosion using the Revised Universal Soil Loss Equation with Sediment Delivery Ratio and the analytic hierarchy process models

AbstractThis research used the Revised Universal Soil Loss Equation (RUSLE) with Sediment Delivery Ratio (SDR) model. The analytic hierarchy process (AHP) method, while also incorporating the use of a geographic information system (GIS) and remote sensing (RS) to predict the annual soil loss rate and spatialise the processes of water erosion at the scale of the Loukkos Watershed, Morocco. The RUSLE model and AHP parameters were estimated using RS data, and the erosion vulnerability zones were determined using GIS. We used five parameters, including precipitation erosivity, soil erodibility, slope length and steepness, vegetation cover, and soil erosion control practices in the RUSLE. For the AHP technique, we used seven geo‐environmental factors, including annual average precipitation, drainage density, lineament density, slope, soil texture, land use/land cover and landform maps. The results of RUSLE indicated that the average annual soil loss varied from 0 to 2388.27 . The total estimated annual potential soil loss was approximately 40 790 220.11 , and a sediment yield estimated by RUSLE‐SDR was 8 647 526.66 , equivalent to 6.65 Mm3. This value is very close to the measured value of 6.81 Mm3, for a difference of 0.16 Mm3. Furthermore, the results of the AHP indicate that the soil erosion potential index varies from 0 to 0.205315 . Overall, nearly 13.7% of the area suffered from severe soil erosion exceeding 50 . Approximately 80% of the Loukkos Watershed area experienced only slight erosion, while the remaining 6% incurred moderate erosion. Integrating GIS and RS into the RUSLE model and AHP helped us robustly estimate the extent and degree of erosion risk. Territorial decision‐makers should adopt our results to develop soil conservation strategies, water management plans and other necessary soil and water conservation measures for this region.

Quantifying soil erosion and soil organic carbon conservation services in indian forests: A RUSLE-SDR and GIS-based assessment

Indian forests, having sixteen types of vegetation, provide various ecosystem services. Forests reduce water erosion of soil, reduce floods and conserve low river flow during dry seasons. Present study estimated annual sedimentation, texture, soil organic carbon control service of forests of India using the Revised Universal Soil Loss Equation (RUSLE) and Sediment Delivery Ratio (SDR) approach through GIS technique along with identifying important drivers responsible for erosion in forests. The soil erosion control service was based on five factors viz., rainfall erosivity, soil erodibility, slope, crop management, conservation practice factor and SDR across the various forest dominated river basins. Geo-detector modelling was performed to evaluate environmental drivers responsible for soil erosion. Valuation of soil control service of the India’s forests was estimated based on damage and replacement cost method. Annual soil loss rate was maximum in Tropical Thorn Forest and in Ganga River basin. Maximum sediment control and SOC conservation against the soil erosion control service by India’ forests were due to Tropical Dry Deciduous Forest with a total annual sedimentation control and SOC conservation of 33,056,560 tonnes and 3,31,115.06 tonnes, respectively. The conservative estimate of the economic value of soil conservation service by the forests of India was US$ 535.6 M with an average of 4.40 US$ ha−1 and a maximum share of value for Tropical Dry Deciduous Forest i.e. 294.18 million US$ and average maximum value for Littoral and Swamp Forest (28.91 US$ ha−1). The soil erosion in Tropical and Sub-tropical Forest was influenced by the interactive effects between NDVI and Bulk Density. In contrast, soil erosion in the temperate and alpine area was influenced by anthropogenic activity in combination with climatic factors. Present study accounts the role of India’s forests for the soil conservation service and may provide inputs to implement forest and reservoir management strategies besides providing information for Integrated Watershed management and Catchment Treatment Plans.

Water soil erosion modeling with RUSLE, GIS & remote sensing: A case study of the AL-Sanaoubar River basin (Syria)

Soil erosion forms a serious ecological challenge to future production and sustainability, with implications of the environmental crisis and the food supply. It is one of the more critical geomorphological problems that threaten environmental sustainability and cause soil degradation along the Syrian coast. The object of this research is to evaluate the rate of probable annual water-induced soil erosion in the AL-Sanaoubar River Basin. By Integrating geographic information system (GIS), and remote sensing techniques with the Universal Soil Loss Equation (RUSLE). The results showed that the soil loss values in the AL-Sanaoubar River Basin ranged between 0–138.15 tons/ha/year, an average of 52.4 tons/ha/year. The total soil loss reached 12,606.11 tons/year for the entire studied area.The classification of possible spatial risk included five grades: very low (91.91%), low (7.62%), medium (0.35%), high (0.10%), and very high (0.01%).It has been noticed high soil erosion values in few portions of the study area, indicating that they had reached a risk stage; these sites were concentrated in the center and east of the studied basin, especially in the plateau and mountainous parts, Slope was a major factor that caused a direct impact on soil erosion. Soil erosion gradually increased with increasing slope in all types of land uses.To test the effectiveness of some soil conservation practices against water erosion, an experiment was conducted at the Mazar Qatrya site in Lattakia governorate during two consecutive seasons. Contour cultivation of the pea crop was applied at different distances, the agricultural method showed a high efficiency in reducing water erosion. Land use managers and Planners can benefit from this research to make suitable provisions and activities to conserve the soil.

Estimation of Maize Residue Cover Using Remote Sensing Based on Adaptive Threshold Segmentation and CatBoost Algorithm

Maize residue cover (MRC) is an important parameter to quantify the degree of crop residue cover in the field and its spatial distribution characteristics. It is also a key indicator of conservation tillage. Rapid and accurate estimation of maize residue cover (MRC) and spatial mapping are of great significance to increasing soil organic carbon, reducing wind and water erosion, and maintaining soil and water. Currently, the estimation of maize residue cover in large areas suffers from low modeling accuracy and poor working efficiency. Therefore, how to improve the accuracy and efficiency of maize residue cover estimation has become a research hotspot. In this study, adaptive threshold segmentation (Yen) and the CatBoost algorithm are integrated and fused to construct a residue coverage estimation method based on multispectral remote sensing images. The maize planting areas in and around Sihe Town in Jilin Province, China, were selected as typical experimental regions, and the unmanned aerial vehicle (UAV) was employed to capture maize residue cover images of sample plots within the area. The Yen algorithm was applied to calculate and analyze maize residue cover. The successive projections algorithm (SPA) was used to extract spectral feature indices from Sentinel-2A multispectral images. Subsequently, the CatBoost algorithm was used to construct a maize residue cover estimation model based on spectral feature indices, thereby plotting the spatial distribution map of maize residue cover in the experimental area. The results show that the image segmentation based on the Yen algorithm outperforms traditional segmentation methods, with the highest Dice coefficient reaching 81.71%, effectively improving the accuracy of maize residue cover recognition in sample plots. By combining the spectral index calculation with the SPA algorithm, the spectral features of the images are effectively extracted, and the spectral feature indices such as NDTI and STI are determined. These indices are significantly correlated with maize residue cover. The accuracy of the maize residue cover estimation model built using the CatBoost model surpasses that of traditional machine learning models, with a maximum determination coefficient (R2) of 0.83 in the validation set. The maize residue cover estimation model constructed based on the Yen and CatBoost algorithms effectively enhances the accuracy and reliability of estimating maize residue cover in large areas using multispectral imagery, providing accurate and reliable data support and services for precision agriculture and conservation tillage.

Cover crop management systems improves soil quality and mitigate water erosion in tropical olive orchards

The production of olive trees in shallow soils in hillslopes requires adequate soil and water conservation systems. In this context, soil use and management besides vegetation cover contributes to better soil quality and the sustainability of the olive cultivation system. Thus, the objective was to determine the physical and chemical properties that are indicative of soil quality in areas of Dystrudepts, under different soil cover management systems in olive cultivation in tropical region. Olive tree culture field experiment was established in 2015, where soil was sampled over three years (2016, 2017 and 2021). The effect of five cover management systems were compared for each agricultural year, namely BS: bare soil in 2015/2016, 2016/2017 and 2017/2021; OBS: olive trees on bare soil in 2015/2016, 2016/2017 and 2017/2021; OSV: olive trees intercropped with mowed spontaneous vegetation in 2015/2016, 2016/2017 and 2017/2021; OJB: olive trees intercropped with jack beans (Canavalia ensiformis L.) in 2015/2016 and 2016/2017, and olive trees crowned intercropped with mowed spontaneous vegetation in 2017/2021; OMI: olive trees intercropped with millet (Pennisetum glaucum L.) in 2015/2016, olive trees intercropped with sunn hemp (Crotalaria juncea L.) in 2015/2017 and olive trees with spontaneous vegetations treated with herbicide (Roundup) in 2017/2021. The soil quality indices (SQI) proved to be sensitive to variations in different types of soil management from the second year of assessment, regarding water erosion. OSV and OJB showed the highest SQI, while OBS showed the lowest values. The SQI demonstrated an inverse correlation with soil and water losses starting from the second year of assessment. This highlights its efficacy in assessment the effects of adopted management on soil quality in the context of water erosion. Moreover, it reinforces the importance of vegetation cover in maintaining soil fertility, resulting in increase of soil organic matter and improving the structuring of Dystrudepts. The attributes that most correlated with the SQI were soil organic matter, effective cation exchange capacity, sum of bases, geometric mean diameter of aggregates, pH and unsaturated soil hydraulic conductivity. These attributes collectively provide valuable insights into soil health and water erosion susceptibility within the olive tree production system.

Mechanisms of influence of forest ecosystems on the aggregate composition and water stability of soil aggregates in the semi-arid area of southeast Ukraine

Modern processes of climate change are accompanied by a number of negative factors, which include aridization, desertification, soil degradation and erosion. The research was were carried out on the territory that is the southern border of the distribution of the late glacial phase of the Dnieper glaciation (Middle Pleistocene, 100–230 thousand years ago). The influence of forest ecosystems on the aggregate composition and water stability of soil aggregates, the features of which determine the protection of soils from erosion and other degradation processes in semiarid conditions, was assessed. It has been established that luvic chernozems of forest ecosystems are characterized by an increased content of aggregates of fractions 2–3, 1–2 and 0.5–1.0 mm, as well as water-stable aggregates of fractions > 5, 0.5–1.0 and 0.25–0.5 mm in the 0–20 cm layer compared to ordinary chernozems of steppe ecosystems. The content of soil organic matter is a determining factor on which the aggregate composition and content of water-stable aggregates in luvic chernozems of forest ecosystems depends. The existence of close direct relationships has been established between the content of soil organic matter and the content of aggregates of the 0.5–1.0 mm fraction, as well as between the content of soil organic matter and the content of water-stable aggregates of fractions 3–5, 2–3 and 1–2 mm in chernozems of steppe and forest ecosystems. The existence of close direct relationships between the sand content and the content of water-stable aggregates of fractions 3–5 and 2–3 mm was revealed. The established increase in the content of soil organic matter and sand in luvic chernozems of forest ecosystems compared to ordinary chernozems of steppe ecosystems is the reason for the improvement in the aggregate composition and the increase in the content of water-stable aggregates. This is a key aspect of increasing the resistance of soils in forest ecosystems to various negative factors, such as desertification, degradation, wind and water soil erosion.

Determining the Dependence of a Landscape’s Ecological Stability and the Intensity of Erosion during 1990–2018

Among the main elements that contribute to climate change are degradation processes and the ecological level of a landscape. These two topics have been discussed and researched for many years, and many studies have been conducted. The idea behind this article is to determine the correlation between the ecological stability of a territory and the intensity of degradation processes and find out how ecological stability affects the intensity of soil erosion and vice versa. The ecological stability was calculated based on various methods during the years analyzed, i.e., 1990, 2006, 2012, and 2018. The soil water erosion measurements were performed for the same period in order to identify the relationship between ecological stability and the intensity of soil erosion. The investigated area is located in the Slovak Republic, and each year reflects different types of management of the territory, reflecting the current situation in the catchment according to the year evaluated. The intensity of the erosion process was measured using a physically based EROSION-3D model based on the precipitation levels derived using the Community Land Model (the CLM). In addition to identifying the relationship between the level of ecological stability and the intensity of erosion, this study also describes the development of ecological stability during the evaluated period together with changes in soil erosion processes. The results show a dependence between the intensity of ecological stability and soil erosion. First of all, it determines whether such a dependence exists at all and also its extent.

Exploitation of Magnetic Susceptibility Data for Soil Stability Analysis: A Watershed Study of the Oued Ghiss Dam in the Central Rif, Morocco

The water erosion of soil in northern Morocco raises significant concerns due to its potential impact on the sustainability and productivity of the land. The objective of our study is to evaluate water erosion by utilizing magnetic susceptibility of soil particles in the watershed of the Oued Ghiss Dam. Magnetic susceptibility measurements were taken on 25cm deep profiles collected from six distinct areas, distributed based on pedology, slope, and land use. The results reveal significant variations in susceptibility. Transects 5 and 6 stand out with significantly higher magnetic susceptibility values compared to other transects, indicating relative soil stability under dense forest cover. Transect 2 also exhibits a range of magnetic susceptibility from 21.05 to 51.67 x 10-8 m³/kg, suggesting relative stability despite slight changes in magnetic susceptibility due to vegetation density and morphometric characteristics. Transects 1, 3, and 4 display lower magnetic susceptibility ranges, indicating signs of active erosion in bare soils. Magnetic signatures of soil particles provide crucial insights into soil dynamics in the Central Rif region of Morocco, emphasizing the impact of geodynamic factors and land use on the degree of evolution and degradation.

Soil peroxidase and polyphenoloxidase activity under soil conservation practices on sloping terrains

Soil water erosion in Bulgaria has a significant negative impact on the arable inclined lands. Two experiments were conducted with wheat and maize with application of traditional and soil protection technologies, on Calcic Chernozem soil, on the slope of 5°. Calcic Chernozems are soils exposed to frequent water erosion processes due to significant structural deficiency and low aggregate stability. The first survey was carried out in the period 2018-2020, and in addition to conventional technologies, surface and vertical mulching (with manure as mulching material) were also tested. The second was carried out in 2020-2023 and included minimal treatments for growing wheat and maize and the inclusion of cover crop (barley) in the crop rotation. An increase in the amount of soil organic carbon was found, as well as an increase of the soil peroxidase and polyphenoloxidase activity. The ratio between two enzymes, is considered as humification factor, is higher in the variants under soil protection technologies. The application of soil conservation treatments such as surface mulching with manure, minimum tillage with vertical manure mulching, as well as minimum tillage combined with cover crop in a wheat-maize rotation on sloping farmlands lead to an improvement of soil organic carbon as well as an increase of soil polyphenoloxidase activity.

Contribution to the physicochemical characterisation of soils in the Beni Boufrah watershed (Central Rif, Morocco)

As part of the study of soil water erosion in the Beni Boufrah watershed, which forms part of the northern slopes of the Central Rif, generally dipping towards the Mediterranean Sea, we carried out soil analyses to determine certain physicochemical characteristics of the soil. These analyses, which consisted of measuring pH, estimating residual moisture content, organic matter and carbonates, and measuring magnetic susceptibility in the horizons of eight profiles sampled from different soils in the Beni Boufrah watershed, are of great interest in understanding the behaviour of these soils with regard to water erosion. The results obtained show that the soils in this catchment area are alkaline, and that their residual moisture and organic matter content are remarkably low, especially in the surface horizons. The carbonate content is only significant in soils resulting from the alteration of parent rocks belonging to the Bokkoya limestone ridge. Magnetic susceptibility measurements show that the soils studied are disturbed and reworked.

2001–2020年中国东北区域土壤水蚀数据集

The black soil area in Northeast China plays an important role in food production and ecological security in China. However, over-cultivation practices have led to severe soil erosion, which seriously threatens food security and ecological environment in Northeast China. Accurate simulations of water erosion with high spatio-temporal resolution are important for advancing sustainable development goals, such as promoting sustainable agriculture and monitoring land degradation in Northeast China. This dataset is based on Google Earth Engine (GEE) cloud platform, integrating multi-source remote sensing data, deconstructing RUSLE model, and optimizing algorithm combinations for each factor of the model. We compared and verified the annual sand transport volume and sand transport modulus data from the main hydrological monitoring stations in Northeast China with the soil erosion modulus estimated by the RUSLE model. Then, we selected the optimal factor algorithm combination based on three accuracy metrics (time series correlation, root mean square error and mean absolute error), and obtained the estimation results of soil water erosion modulus with the resolution of 250 m. This dataset can better depict the spatial distribution and temporal changes of soil erosion modulus in Northeast China from 2001 to 2020. It can serve as an effective reference for soil erosion control and assessments in Northeast China.

The effect of slope incline on the characteristics of particles ejected during the soil splash phenomenon

Slope incline is one of the factors affecting the soil water erosion process. Most of the work to date related to erosion has been on large-scale studies based on rainfall events or laboratory investigations with the use of simulators, where the displaced mass of soil was determined. However, there is a lack of studies providing information about splash erosion on slopes in relation to single-drop impact methodology, that allows for the examination of the basic processes of the phenomenon. Thus, the aim of this study was a quantitative description of the splash phenomenon on a simulated slope affected by a single drop impact, with respect to the influence of slope incline on the number of ejected particles and their characteristics. The investigation was carried out using three types of soil with different textures in moistened conditions (i.e. pressure head corresponding to 1.0 kPa) and three variants of slope incline: 5°, 15°, and 30°. A drop with a diameter of 4.2 mm was allowed to fall freely on soil surface with kinetic energy equal 1.42 mJ. The splash phenomenon was registered by a set of three synchronized high-speed cameras and combined with PTV software (Particle Tracking Velocimetry) to identify and track displaced particles. The methodology used made it possible to observe the course of the phenomenon and determine the following quantities: the number and size of ejected particles, ejection velocity and angle, displacement range, and also the contribution of the kinetic energy of the falling drop transferred to the ejected particles. The measured quantities were specified for the particles ejected in upslope and downslope directions. It was found that: (i) the interaction between different slope inclines and the particle size distribution of the soils influenced the surface conditions, which had a significant effect on the course of the splash phenomenon; (ii) the number of ejected particles decreased with the increasing slope, which was directly related to limited ejection in the upslope direction; (iii) the influence of slope incline was mostly visible in the ejection angle, range of displacement and sizes of ejected particles; (iv) the portion of the falling drop energy transferred to ejected particles decreased with increasing slope. The obtained results could enhance the development of physical models of splash erosion. A more thorough understanding and better recognition of the mechanisms governing this phenomenon at all stages could contribute to the development of more effective methods for protecting soil against erosion.