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The terrain in the loess hilly area of western Henan is fragmented, with steep slopes and weak soil erosion resistance. The substantial soil erosion in this region results in plenty of problems, including decreased soil productivity and ecological degradation. These problems significantly hinder the social and economic development in the region. Soil conservation planning and ecological development require accurate soil erosion surveys. However, the studies of spatio-temporal patterns, evolution, and the driving force of soil erosion in this region are insufficient. Therefore, based on a multi-stage, unequal probability, systematic area sampling method and field investigation, the soil erosion of the loess hilly area of western Henan was quantitatively evaluated by the Chinese Soil Loss Equation (CSLE) in 2022. The impact forces of soil erosion were analyzed by means of a geographic detector and multiple linear regression analysis, and the key driving factors of the spatio-temporal evolution of soil erosion in this region were revealed. The results were as follows. (1) The average soil erosion rate of the loess hilly area in western Henan in 2022 was 5.94 t⋅ha−1⋅a−1, with a percentage of soil erosion area of 29.10%. (2) High soil erosion rates mainly appeared in the west of Shangjie, Xingyang, and Jiyuan, which are related to the development of production and construction projects in these areas. The areas with a high percentage of soil erosion area were in the north (Xinan and Yima), west (Lushi), and southeast (Songxian and Ruyang) of the study area. Moreover, areas with the most erosion were found in forest land, cultivated land, and areas with a slope above 25°. (3) At the landscape level, the number and density of patches of all land types, except orchard land, increased significantly, and the boundary perimeter, landscape pattern segmentation, and degree of fragmentation increased. (4) The geographical detector and multiple linear regression analysis indicated that the driving forces of soil erosion are mainly topographic and climatic (slope length, elevation, precipitation, and temperature). Soil erosion was significantly influenced by the density of landscape patches. These maps and factors influencing soil erosion can serve as valuable sources of information for regional soil conservation plans and ecological environment improvements. [ABSTRACT FROM AUTHOR]

The terrain in the loess hilly area of western Henan is fragmented, with steep slopes and weak soil erosion resistance. The substantial soil erosion in this region results in plenty of problems, including decreased soil productivity and ecological degradation. These problems significantly hinder the social and economic development in the region. Soil conservation planning and ecological development require accurate soil erosion surveys. However, the studies of spatio-temporal patterns, evolution, and the driving force of soil erosion in this region are insufficient. Therefore, based on a multi-stage, unequal probability, systematic area sampling method and field investigation, the soil erosion of the loess hilly area of western Henan was quantitatively evaluated by the Chinese Soil Loss Equation (CSLE) in 2022. The impact forces of soil erosion were analyzed by means of a geographic detector and multiple linear regression analysis, and the key driving factors of the spatio-temporal evolution of soil erosion in this region were revealed. The results were as follows. (1) The average soil erosion rate of the loess hilly area in western Henan in 2022 was 5.94 t⋅ha−1⋅a−1, with a percentage of soil erosion area of 29.10%. (2) High soil erosion rates mainly appeared in the west of Shangjie, Xingyang, and Jiyuan, which are related to the development of production and construction projects in these areas. The areas with a high percentage of soil erosion area were in the north (Xinan and Yima), west (Lushi), and southeast (Songxian and Ruyang) of the study area. Moreover, areas with the most erosion were found in forest land, cultivated land, and areas with a slope above 25°. (3) At the landscape level, the number and density of patches of all land types, except orchard land, increased significantly, and the boundary perimeter, landscape pattern segmentation, and degree of fragmentation increased. (4) The geographical detector and multiple linear regression analysis indicated that the driving forces of soil erosion are mainly topographic and climatic (slope length, elevation, precipitation, and temperature). Soil erosion was significantly influenced by the density of landscape patches. These maps and factors influencing soil erosion can serve as valuable sources of information for regional soil conservation plans and ecological environment improvements.

Copyright of Pearl River is the property of Pearl River Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Inappropriate soil management accelerates soil erosion and thus poses a serious threat to food security and biodiversity. Due to poor data availability and fragmented terrain, the landscape pattern of garden erosion in tropical Xishuangbanna is not clear. In this study, by integrating multi-source satellite imagery, field investigation and visual interpretation, we realized high-resolution mapping of gardens and soil conservation measures at the landscape scale. The Chinese Soil Loss Equation (CSLE) model was then performed to estimate the garden erosion rates and to identify critical erosion-prone areas; the landscape pattern of soil erosion was further discussed. Results showed the following: (1) For the three major plantations, teas have the largest degree of fragmentation and orchards suffer the highest soil erosion rate, while rubbers show the largest patch area, aggregation degree and soil erosion ratio. (2) The average garden erosion rate is 1595.08 t·km−2a−1, resulting in an annual soil loss of 9.73 × 106 t. Soil erosion is more susceptible to elevation and vegetation cover rather than the slope gradient. Meanwhile, irreversible erosion rates only occur in gardens with fraction vegetation coverage (FVC) lower than 30%, and they contribute 68.19% of total soil loss with the smallest land portion, indicating that new plantations are suffering serious erosion problems. (3) Garden patches with high erosion intensity grades and aggregation indexes should be recognized as priorities for centralized treatment. For elevations near 1900 m and lowlands (<950 m), the decrease in the fractal dimension index of erosion-prone areas indicates that patches are more regular and aggregated, suggesting a more optimistic conservation situation. [ABSTRACT FROM AUTHOR]

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.

Satellite remote sensing of grassland ecosystem restoration requires considering both the above-ground biomass and soil information, and the latter is even more crucial due to the value and restoration difficulty of soil productivity. In this study, we proposed an approach to support the restoration pattern for mountainous grasslands at regional scale. The approach integrates different aspects and key processes, including degradation status, restoration potential and recovery capability, compared to a reference state. Specifically, we illustrated the method with the case of grasslands in southwestern China from a conservation perspective. Soil erosion conditions, net primary productivity and regrowth rate of grasslands were selected as indicators to reveal restoration possibilities. The results showed that the method proposed for remote sensing identification of grassland distribution has an overall accuracy of 88.21% at the regional scale. 59.54% of grasslands in Zhaotong are being eroded with an unsustainable erosion rate greater than the tolerant soil loss, and the average annual soil erosion rate is 952.17 t/(km2·a). Meanwhile, there is obvious spatial heterogeneity in soil erosion factors, vegetation restoration potential and regrowth rate, and the dry–hot valley of Jinsha River in the southwest is much more sensitive to climate change and vulnerable than other regions. The grassland vegetation cover revealed a fluctuating trend and protection of grassland vegetation on soil from erosion has an obvious lag, restoration efforts should be focused on the months before the arrival of the rainy season. In light of various grassland types, the overlay zoning results suggest various restoration patterns of natural repair and manual intervention should be employed for different grasslands. Urgent action is needed to face the challenge and process of grassland degradation and restore its sustainability with shared understanding by taking the stakeholders, collaborations and mutual relationships among different roles into account (e.g., scientist, government and herdsman). [ABSTRACT FROM AUTHOR]

Inappropriate soil management accelerates soil erosion and thus poses a serious threat to food security and biodiversity. Due to poor data availability and fragmented terrain, the landscape pattern of garden erosion in tropical Xishuangbanna is not clear. In this study, by integrating multi-source satellite imagery, field investigation and visual interpretation, we realized high-resolution mapping of gardens and soil conservation measures at the landscape scale. The Chinese Soil Loss Equation (CSLE) model was then performed to estimate the garden erosion rates and to identify critical erosion-prone areas; the landscape pattern of soil erosion was further discussed. Results showed the following: (1) For the three major plantations, teas have the largest degree of fragmentation and orchards suffer the highest soil erosion rate, while rubbers show the largest patch area, aggregation degree and soil erosion ratio. (2) The average garden erosion rate is 1595.08 t·km−2a−1, resulting in an annual soil loss of 9.73 × 106 t. Soil erosion is more susceptible to elevation and vegetation cover rather than the slope gradient. Meanwhile, irreversible erosion rates only occur in gardens with fraction vegetation coverage (FVC) lower than 30%, and they contribute 68.19% of total soil loss with the smallest land portion, indicating that new plantations are suffering serious erosion problems. (3) Garden patches with high erosion intensity grades and aggregation indexes should be recognized as priorities for centralized treatment. For elevations near 1900 m and lowlands (

Soil erosion has posed a serious threat to the ecological balance and food security in the most fragile environment of the Loess Plateau. Frequent human activities are drastically changing the spatial pattern of land use in the economic and social development. Therefore, it is of great significance to predict the soil erosion under different strategies of land use for the regional coordinated development in the future. Taking the Jiuyuangou watershed as the research object, this study aims to propose an improved FLUS-CSLE model for the prediction of the spatial distribution pattern of land use in different scenarios. The vegetation coverage factor (B) and the tillage measure factor (T) were also calculated in the future scenario. The CSLE model was used to evaluate the soil erosion status in the historical period (2010-2020). The vegetation coverage factor and tillage measure factor were combined to predict the soil erosion under various scenarios of land use in 2025. Finally, a systematic analysis was made to determine the response of land use types to soil erosion status. The results show that: 1) The land use types were grassland (62.23%) and forest land (28.41%), followed by cropland, buildings, and water in the study area. There were the great variations in the spatial distribution pattern of land use. Specifically, the areas of forest and grassland increased by 8.36% from 2010 to 2020, whereas, the area of cropland was decreased by 30.3%. 2) The average modulus of soil erosion in the three years of 2010, 2015, and 2020 were 19.49, 15.83, and 20.7 t/(hm2·a), respectively, indicating a trend of first decreasing and then increasing. The soil erosion modulus of land use types was ranked in the descending order of the cropland (40.56 t/(hm2·a)) > grassland (18.79 t/(hm2·a)) > building (10.25 t/(hm2·a)) > forest land (8.02 t/(hm2·a)). 3) Under the positive ecological protection scenario, the area of forest and grassland in 2025 was basically the same as that in the natural development scenario, but the proportion of forest land increased. The area of forest and grassland was increased by 5.06% compared with the economic growth scenario. The area of cropland was increased by 1.20% compared with the natural development scenario and decreased by 14.73% compared with the economic growth scenario. 4) The soil erosion moduli were 24.3, 22.9, and 18.3 t/(hm2·a), respectively, under the natural development, economic growth, and ecological protection scenarios of the watershed in 2025. Therefore, an active ecological protection mode can be expected to appropriately expand the building area in the needs of economic development. Anyway, a rapid and efficient prediction of soil erosion can be given for the management strategies in the various scenarios of land use in the future. The findings can also provide the scientific reference for the decision-making on land use, as well as soil and water conservation in the watershed. [ABSTRACT FROM AUTHOR]

Slope cropland erosion is the most serious land degradation problem in plateau mountainous areas. A great threat has been posed to regional food security and sustainability of agriculture. Particularly, the Wenshan Prefecture of Yunnan Province is characterized by serious soil erosion in China. Taking the Wenshan Prefecture as an example, this study aims to quantitatively evaluate the soil erosion of the farmland and spatial features using multi-source remote sensing data, such as the Third National Land Survey, Water Conservancy Sampling Survey, and the Wide Field of View (WFV) imaging system of GaoFen-6 (GF-6) satellite. Firstly, the non-cultivated land was masked in the GF-6 image with the Third National Land Survey data. The sampling units were also used as the sample set. Secondly, object-oriented multi-scale segmentation was performed on the GF-6 image, where the Jeffries-Matusita distance was adopted to determine the preferred feature set of spectral, texture and shape. Thirdly, Random Forest (RF) algorithm was employed to quickly and automatically extract the terraces. The fine rasterization of the E factor was realized to combine the engineering measures in the sampling units. Finally, the Chinese Soil Loss Equation (CSLE) model was utilized to conduct a fine quantitative assessment of soil erosion in the mountainous arable land. A spatial autocorrelation analysis was also carried out on the soil erosion features and influence factors in the GeoDa software in order to reveal the spatial distribution pattern. The results indicated that: 1) The distribution of arable land in the Wenshan Prefecture was bounded by the Guangnan, Xichou, and Maguan, indicating a descending pattern from the west to the east. There was about 6 252.85 km2 of slope cropland in the study area, accounting for 79.27% of the total arable land. The cultivated land was 3 929.57 km² with the soil and water conservation engineering measures, accounting for 49.79% of the total arable land area. 2) Soil erosion modulus of the cultivated land ranged from 0 to 118 540.97 t/(km²·a) with an average erosion modulus of 5 180.72 t/(km²·a). About 69.99% of the total cultivated land was suffering from serious erosion. The total annual amount of soil loss from the cultivated land was 40.815 million tons, 20.60% of which was eroded from the land with the soil conservative measures. By contrast, the soil loss from the cultivated land without any soil conservative measures was 32.407 million tons, accounting for 79.40% of the total. There was also a significant difference in the response of erosion to the slope and elevation, particularly with the vertical zonal characteristics. The area and intensity of soil erosion increased first and then decreased, as the elevation and slope increased. The high incidence areas of erosion were found between the elevation zones of 1 000-1 400 m and 1 400-1 800 m, accounting for 27.23% and 50.54% respectively. The steep slope cropland (>20°) erosion also contributed 75.30% of the total erosion. 3) The spatial distribution of cropland erosion demonstrated outstanding aggregation characteristics and strong spatial correlations with the R and LS factors, respectively. Specifically, the Maguan, Malipo, Xichou, and Funing in the south of Wenshan were the high-value centers of erosion, and, the low-value centers were found in the Wenshan, Yanshan, Qiubei, and Guangnan in the central and western regions. The fine quantitative assessment of soil erosion was achieved to automatically extract the soil erosion factors on the regional scale for the spatial autocorrelation analysis. The finding can provide a strong reference to accurately allocate the regional soil and water conservation resources, as well as the ecological environment construction. [ABSTRACT FROM AUTHOR]

Satellite remote sensing of grassland ecosystem restoration requires considering both the above-ground biomass and soil information, and the latter is even more crucial due to the value and restoration difficulty of soil productivity. In this study, we proposed an approach to support the restoration pattern for mountainous grasslands at regional scale. The approach integrates different aspects and key processes, including degradation status, restoration potential and recovery capability, compared to a reference state. Specifically, we illustrated the method with the case of grasslands in southwestern China from a conservation perspective. Soil erosion conditions, net primary productivity and regrowth rate of grasslands were selected as indicators to reveal restoration possibilities. The results showed that the method proposed for remote sensing identification of grassland distribution has an overall accuracy of 88.21% at the regional scale. 59.54% of grasslands in Zhaotong are being eroded with an unsustainable erosion rate greater than the tolerant soil loss, and the average annual soil erosion rate is 952.17 t/(km2·a). Meanwhile, there is obvious spatial heterogeneity in soil erosion factors, vegetation restoration potential and regrowth rate, and the dry–hot valley of Jinsha River in the southwest is much more sensitive to climate change and vulnerable than other regions. The grassland vegetation cover revealed a fluctuating trend and protection of grassland vegetation on soil from erosion has an obvious lag, restoration efforts should be focused on the months before the arrival of the rainy season. In light of various grassland types, the overlay zoning results suggest various restoration patterns of natural repair and manual intervention should be employed for different grasslands. Urgent action is needed to face the challenge and process of grassland degradation and restore its sustainability with shared understanding by taking the stakeholders, collaborations and mutual relationships among different roles into account (e.g., scientist, government and herdsman).

Land degradation induced by soil erosion is widespread in semiarid regions globally and is common in the agro–pastoral ecotone of northern China. Most researchers identify soil erosion by wind and water as independent processes, and there is a lack of research regarding the relative contributions of wind and water erosion and the interactions between them in what is referred to here as compound soil erosion (CSE). CSE may occur in situations where wind more effectively erodes a surface already subject to water erosion, where rainfall impacts a surface previously exposed by wind erosion, or where material already deposited by wind is subject to water erosion. In this paper, we use the Chinese Soil Loss Equation (CSLE) and the Revised Wind Erosion Equation (RWEQ) to calculate the rate of soil erosion and map the distribution of three types of soil erosion classified as (i) wind (wind-erod), (ii) water (water-erod), and (iii) CSE (CSE-erod) for the study area that spans more than 400,000 km2 of sand- and loess-covered northern China. According to minimum threshold values for mild erosion, we identify water-erod, wind-erod, and CSE-erod land as occurring across 41.41%, 13.39%, and 27.69% of the total area, while mean soil erosion rates for water-erod, wind-erod, and CSE-erod land were calculated as 6877.65 t km−2 yr−1, 1481.47 t km−2 yr−1, and 5989.49 t km−2 yr−1, respectively. Land subject to CSE-erod is predominantly distributed around the margins of those areas that experience wind erosion and water erosion independently. The CSLE and RWEQ do not facilitate a direct assessment of the interactions between wind and water erosion, so we use these equations here only to derive estimates of the relative contributions of wind erosion and water erosion to total soil erosion and the actual mechanisms controlling the interactions between wind and water erosion require further field investigation. It is concluded that CSE is an important but underappreciated process in semiarid regions and needs to be accounted for in land degradation assessments as it has substantial impacts on agricultural productivity and sustainable development in regions with sandy and/or loess-covered surfaces. [ABSTRACT FROM AUTHOR]

The Qinghai-Tibet Plateau( QTP) is an important ecological barrier in China. In recent years, the large-scale conversion and reclamation of farmland in the QTP are bound to weaken or induce soil erosion. To explore the impact of different land-use change patterns on soil erosion in the QTP, taking the farming area of the QTP as an example, based on the CSLE model, the soil erosion status of the farming area in 2015 is analyzed, and the comprehensive index of soil erosion intensity change and the contribution of erosion reduction is proposed for the first time. The concept and calculation formula is used to quantify the impact of cultivated land changes on soil erosion and analyze the contribution of different cultivated land change patterns to soil erosion reduction. The results show that: ① The average soil erosion module in the farming areas of the QTP in 2015 is 195.6 t/(hm²·a), and the potential annual soil loss is approximately 446.51 × 106 t/a. ② The composite index of variation in soil erosion intensity in returning farmland to forest, back tillage to grass, and unused land-to-farmland are -378.24, -118.54 and -5.44 t/(hm²·a), and the effect of reducing soil erosion decreases in turn, while the composite index of variation in soil erosion intensity in grassland and forest land reclamation as cultivated land, and farmland that degrades into unused land are 16.53, 32.34 and 200.61 t/(hm²·a), the effect of increasing soil erosion increased in turn. ③ Land-use changes in 2000-2015 reduced soil erosion intensity by 245.54 t/(hm²·a) in the agricultural areas of the QTP with a decrease of 55.66% compared to the unchanging land-use scenario. Under the dual influence of soil erosion intensity change comprehensive index and area, the order of contribution of different land-use changes to soil erosion reduction is: returning farmland to grassland > returning farmland to forest > conversion of unused land to cultivated land > conversion of woodland to cultivated land > conversion of cultivated land to unused land > conversion of grassland to cultivated land. The research results provide a reference for the sustainable development and utilization of water and soil resources and ecological environmental protection in the agricultural areas of the QTP. [ABSTRACT FROM AUTHOR]

Copyright of Arid Zone Research / Ganhanqu Yanjiu is the property of Arid Zone Research Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

• Human activities have significantly altered land use in Chinese Loess Plateau. • Vegetation restoration and terrace construction have effectively mitigated soil erosion. • Vegetation changes are the principal drivers of soil erosion dynamics on the Loess Plateau. 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. [ABSTRACT FROM AUTHOR]

In order to explore the effect of tourism disturbance on the mountain scenic spot in west Baiyanggou watershed, we quantitatively estimated the economic loss of water erosion under different disturbance intensities, and then analyzed the change law of water erosion economic loss. The relationship of tourism disturbance with soil physical and chemical properties and vegetation coverage was also evaluated, based on data collected in the national soil erosion survey and the Chinese Soil Loss Equation（CSLE）and water erosion economic loss evaluation model. The results showed that under different tourism disturbance intensities, the soil physical and chemical properties and vegetation coverage were significantly different. Compared with the no disturbance sites, the decrease of soil water content, saturated water content, and soil porosity in severe sites were 51.67%, 32.23%, and 13.30%, respectively. The contents of soil available N, P, and organic matter decreased with increasing disturbance intensity, but the content of soil available K tended to increase. The vegetation coverage of the light, moderate, and severe disturbance sites decreased by 14.18%, 43.32%, and 92.35%, respectively, compared with the control group. With the increase of tourism disturbance intensity, the values of soil erodibility K and biological measure B increased significantly, and soil erosion also significantly increased（P<0.05）. Compared with light disturbance, the increase of soil erosion modulus in moderate and severe disturbance sites were 79.31% and 204.79%, respectively. On-site and off-site economic losses as well as total water erosion economic losses showed an increasing trend with disturbance intensity. Among them, on-site economic loss was much greater than off-site economic loss, and soil nutrient loss and vegetation diversity loss were the main contributors to the total economic loss of water erosion, which accounted for 93.56%, 92.68%, and 94.94% of the total economic loss of water erosion in the mild, moderate, and severe disturbance sites, respectively. When the disturbance intensity increased, the loss of vegetation diversity was higher than the loss of soil nutrients, and it would have a primary water erosion economy loss of 1.17×104 yuan·hm-2 ·a-1 and 2.49×104 yuan·hm-2 ·a-1 in moderate and severe sites, respectively. Vegetation coverage was the most sensitive to water erosion economic loss. Every 1% reduction in vegetation coverage lead to 4.98×104 yuan increasing in water erosion economic loss. The study also indicated that tourism disturbance intensity is a key factor affecting the water erosion intensity and economic loss in mountain scenic spots. Therefore, to control the intensity of tourism disturbance, it should be combined with the analysis of soil erosion parameters, strengthening the management of soil exposure, the use of plant trample resistant vegetation, and assessment of tourism carrying capacity. [ABSTRACT FROM AUTHOR]

Black soil region in Northeast China is an important commodity grain base in China. Soil erosion can deteriorate in the valuable black soil resources; even threaten the safety of grain production. Assessment of soil erosion becomes an inevitable way to control soil erosion, and further to evaluate the benefits of soil and water conservation. However, the multi-scale complex factors can make it difficult to the accurately assess soil erosion. It is also necessary to detect the effects of land use and topography on soil erosion. Normally, the evaluation data of soil erosion include modulus, amount, and intensity of soil erosion. These indexes have different meanings and uses in regional soil erosion assessment. In order to better present the evaluation data of soil erosion, a research region was taken as Baiquan County in rolling hilly regions in Northeast China. Chinese Soil Loss Equation (CSLE) was used to quantitatively evaluate the soil erosion, and systematically analyze the influences that caused by land use and topographic factors. A "landing" scheme was proposed to achieve regional evaluation of soil erosion. The results showed that the average modulus of soil erosion in Baiquan County was 6.77 t/(hm²·a), and the area proportion of soil erosion was 39.35%, indicating a great spatial heterogeneity in soil erosion. The extremely severe erosion was mainly distributed in the hilly areas in the southeast, and the rolling hilly regions in the northwest of Baiquan. This distribution can be attributed to the slope arable land occurred in this area, together with the influence of the terrain. Specifically, the intensity of soil erosion can be high as the increase of the slope. In addition, the intensity of soil erosion showed a trend of increasing first and then decreasing, as the length of the slope becomes longer. The amount of soil erosion is also an important indicator for the evaluation of soil erosion. In the contribution to the amount of erosion, the slope from 1° to 2° showed the largest amount of erosion, followed by 3° to 5° and 2° to 3°. The slope length from 100 to 200 m can contribute the most amount of soil erosion, followed by the slope length of 200 to 400 m and 50 to 100 m. Sloping farmland was characterized by high intensity of soil erosion. Compared with the forest land, the large slope was not the main source of soil erosion amount due to high vegetation coverage and relatively low soil erosion modulus. Therefore, the sloping farmland can be the key area for soil erosion control. This infers that the selection of appropriate indicator can be significant to present the evaluation data of soil erosion. This study demonstrated that the area proportion of soil erosion can be selected for the better evaluation of regional soil erosion at the scale of small watersheds and water conservation planning. This finding can provide an effective way to achieve assessment for regional soil erosion in the “landing” scheme. [ABSTRACT FROM AUTHOR]

The Universal Soil Loss Equation (USLE) is an empirical equation commonly applied to predict soil erosion throughout the world. In China, the Chinese Soil Loss Equation (CSLE) has been developed for estimating annual soil erosion by water on the basis of the USLE. It is proven that two factors (i.e., sampling density and extrapolation method) are important in the application of CSLE for soil erosion survey and evaluation. In this study, based on the SPOT 6 image (1.5 m resolution) and the 1:10,000 topographic map in Yishui county of the Yimeng Mountain Area (YMA), eastern China, two sampling densities (1% and 4%) were selected and three extrapolation methods (grid based calculation, direct extrapolation, and Kriging extrapolation based on sampling units) were adopted to compare their effect on the CSLE calculated soil erosion condition and status. Results showed that estimated soil erosion by direct extrapolation and Kriging extrapolation methods varies largely with sampling density. The discrepancy of the soil erosion area ratios calculated by the two methods are 6.5% and 7.7% under the 1% and 4% sampling density, and the relative discrepancies are 15.9% and 16.2%, respectively. But the grid calculation method is less affected by sampling density. The discrepancy of soil erosion area ratios is only 0.9% and 2.0%, respectively, under the 1% with 4% sampling density. Considering both field workload and prediction accuracy of soil erosion, the 1% sampling density with the grid calculation method is recommended when high resolution remotely sensed data are available. Otherwise, the 4% sampling density with either extrapolation method should be used. The research can provide useful reference information for ensuring the accuracy and reducing the survey workload on the application of CSLE in other areas. [ABSTRACT FROM AUTHOR]

• We proposed a quantitative assessment model to quantify anthropogenic soil erosion. • The anthropogenic soil erosion is about twice the natural soil erosion. • Annual average anthropogenic soil erosion deceased by 69.63 t/(km2·a) from 2000 to 2018. • Contribution rates of human activities and natural factors were calculated. • Human activities represent the dominant factor inducing soil erosion. Soil erosion is a severe global eco-environmental problem threatening human survival and development. It is the combined result of natural factors and human activities. Human activities have played a key role in soil erosion by both promoting and inhibiting it. Only by effectively quantifying anthropogenic soil erosion and analyzing its contribution to actual soil erosion can we alleviate and solve the problem of soil erosion in a targeted manner. In view of this and taking Jiangxi Province as an example, we propose a quantitative assessment model (QAM) based on the Chinese Soil Loss Equation (CSLE) model to quantify anthropogenic soil erosion and construct a contribution rate (CR) to explain the impact degree of human activities on soil erosion. The results were as follows: 1) the annual average anthropogenic soil erosion in 2000, 2010, and 2018 was 309.96, 287.07, and 240.32 t/(km2·a), respectively, with a decrease of 69.63 t/(km2·a) (22.47 %) throughout 2000–2018, indicating that human activities aggravate soil erosion, although this aggravating effect tends to weaken over time; 2) human activities represent the dominant factor inducing soil erosion, and the annual average CR values of human activities were all above 55 % in 2000, 2010, and 2018, larger than the annual average CR values of natural factors in each year. The QAM can provide a methodological reference for the quantification of anthropogenic soil erosion at the regional scale, and the CR can be used to analyze the degree of anthropogenic impact on soil erosion. [ABSTRACT FROM AUTHOR]

As a form of land degradation, soil erosion directly threatens the sustainability of natural resources and the environment. The impacts of humans on soil erosion are profound and complex, especially in the areas with frequent human activities. Moreover, the great variability of human activities at the spatial and time scales precludes a comprehensive understanding of how humans affect regional erosion. This study evaluated soil erosion by water from 1985 to 2015 occurring in South China, which is densely populated and has been intensively exploited, based on the Chinese Soil Loss Equation (CSLE) and multisource data including remote sensing images, meteorological station information and geographic data. A quantitative method combining traceability thinking and residual trend approach was employed to distinguish the relative contributions of climate change and human activities. The results showed that the average amount of soil erosion exhibited a significant decreasing trend from 1985 to 2015, which was consistent with the national water census data and previous studies. Anthropogenic factors played a more vital role than natural variables in the evolution of soil erosion, the multiyear average contribution of which was 63.90%. The area in which anthropogenic factors alleviated soil erosion covered approximately 83.70% of the study area. These results indicate that soil and water conservation practices have made outstanding contributions to the reduction of soil erosion in South China. However, the impacts of the expansion of building land and the development of plantations on aggravating soil erosion cannot be ignored. For future soil erosion control, we observed the diminishing marginal effect of investments in soil and water conservation, and a higher governance potential in the severely eroded regions, which made the severely eroded poor land a primary for comprehensive ecological management. This study aims to provide valuable insights for decision makers in South China to better understand the impacts of humans on the evolution of soil erosion and could provide scientific support for reducing regional soil loss and enhancing the sustainable development of the ecological environment. • Soil erosion in South China exhibited a clearly decreasing trend from 1985 to 2015. • Anthropogenic factors played a more impactful role than natural variables. • The effect of human activities was more likely to mitigate erosion. • Some meaningful soil and water conservation strategies were proposed. [ABSTRACT FROM AUTHOR]