Soil erosion in the Hare watershed led to significant land degradation,water pollution,and reduced agricultural productivity.Despite its effects,very few researchers have used combined morphometric and RUSLE model tec...Soil erosion in the Hare watershed led to significant land degradation,water pollution,and reduced agricultural productivity.Despite its effects,very few researchers have used combined morphometric and RUSLE model techniques to quantify soil erosion and thereby prioritize impacted areas.This work used an automated GIS-based tool(SWPT)to prioritize crucial areas based on topohydrological and morphometric factors and predict soil loss in sub-watersheds using the RUSLE model.Land use/cover data were obtained from Landsat imagery,while slope and morphometric information were extracted from digital elevation data with a resolution of 12.5 m.Soil erodibility was determined using Ethiopian soil maps,and rainfall erosivity was computed using meteorological data.An average annual soil loss of 49 t ha-1 yr-1 was observed in the Hare watershed.Sub-watershed 11 was found to be the most affected,with an average annual soil loss of 85.12 t ha-1 yr-1and a compound parameter value(CPV)of 0.059.Subwatershed 17 has the least amount of soil loss,with 3.67t ha-1 yr-1 and a CPV of 1.32.The study emphasizes the usefulness of integrating RUSLE and morphometric analysis for soil and water conservation planning,suggesting a variety of modeling tools in data-sparse locations to quantify and prioritize erosion-prone areas.展开更多
Soil erosion has been recognized as a critical environmental issue worldwide.While previous studies have primarily focused on watershed-scale soil erosion vulnerability from a natural factor perspective,there is a not...Soil erosion has been recognized as a critical environmental issue worldwide.While previous studies have primarily focused on watershed-scale soil erosion vulnerability from a natural factor perspective,there is a notable gap in understanding the intricate interplay between natural and socio-economic factors,especially in the context of spatial heterogeneity and nonlinear impacts of human-land interactions.To address this,our study evaluates the soil erosion vulnerability at a provincial scale,taking Hubei Province as a case study to explore the combined effects of natural and socio-economic factors.We developed an evaluation index system based on 15 indicators of soil erosion vulnerability:exposure,sensitivity,and adaptability.In addition,the combination weighting method was applied to determine index weights,and the spatial interaction was analyzed using spatial autocorrelation,geographical temporally weighted regression and geographical detector.The results showed an overall decreasing soil erosion intensity in Hubei Province during 2000 and 2020.The soil erosion vulnerability increased before 2000 and then.The areas with high soil erosion vulnerability were mainly confined in the central and southern regions of Hubei Province(Xiantao,Tianmen,Qianjiang and Ezhou)with obvious spatial aggregation that intensified over time.Natural factors(habitat quality index)had negative impacts on soil erosion vulnerability,whereas socio-economic factors(population density)showed substantial spatial variability in their influences.There was a positive correlation between soil erosion vulnerability and erosion intensity,with the correlation coefficients ranging from-0.41 and 0.93.The increase of slope was found to enhance the positive correlation between soil erosion vulnerability and intensity.展开更多
Droughts and soil erosion are among the most prominent climatic driven hazards in drylands,leading to detrimental environmental impacts,such as degraded lands,deteriorated ecosystem services and biodiversity,and incre...Droughts and soil erosion are among the most prominent climatic driven hazards in drylands,leading to detrimental environmental impacts,such as degraded lands,deteriorated ecosystem services and biodiversity,and increased greenhouse gas emissions.In response to the current lack of studies combining drought conditions and soil erosion processes,in this study,we developed a comprehensive Geographic Information System(GIS)-based approach to assess soil erosion and droughts,thereby revealing the relationship between soil erosion and droughts under an arid climate.The vegetation condition index(VCI)and temperature condition index(TCI)derived respectively from the enhanced vegetation index(EVI)MOD13A2 and land surface temperature(LST)MOD11A2 products were combined to generate the vegetation health index(VHI).The VHI has been conceived as an efficient tool to monitor droughts in the Negueb watershed,southeastern Tunisia.The revised universal soil loss equation(RUSLE)model was applied to quantitatively estimate soil erosion.The relationship between soil erosion and droughts was investigated through Pearson correlation.Results exhibited that the Negueb watershed experienced recurrent mild to extreme drought during 2000–2016.The average soil erosion rate was determined to be 1.8 t/(hm2•a).The mountainous western part of the watershed was the most vulnerable not only to soil erosion but also to droughts.The slope length and steepness factor was shown to be the most significant controlling parameter driving soil erosion.The relationship between droughts and soil erosion had a positive correlation(r=0.3);however,the correlation was highly varied spatially across the watershed.Drought was linked to soil erosion in the Negueb watershed.The current study provides insight for natural disaster risk assessment,land managers,and stake-holders to apply appropriate management measures to promote sustainable development goals in fragile environments.展开更多
Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss cos...Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss costs a profound amount of the national GDP and deters land productivity.Quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource management.Therefore,this study aimed at estimating the mean annual soil loss rate of Gilgel Abay watershed which has critical implications on Lake Tana and Abbay River(Upper Blue Nile River),using RUSLE and morphometric analysis methods.Datasets including rainfall,soil,Digital Elevation Model and land use/land cover were used to generate important parameters required for the soil loss estimation.Data collected through field observation,consultation with experts and document analysis were used for validation purposes.The results of the study reveal that the watershed experienced an average soil loss rate of 39.8 t ha^(-1)yr^(-1).Subsequently,nearly 25%(37,038 ha)of the watershed is threatened by moderate to very severe soil loss.Among the four sub watersheds,sub watershed 3(S3)and sub watershed 4(S4),which consist of about 65%(105,000 ha)of the total area of the study watershed,experienced an annual soil loss rate of over 30 t ha^(-1)yr^(-1).The amount of soil loss that the study watershed has experienced is above the soil loss tolerance level of Ethiopia(2-18 t ha^(-1)yr^(-1))and the tropical region(10 t ha^(-1)yr^(-1)).Similarly,the results of morphometric analysis showed that the studied watershed has S-shaped hypsometric curve,an indication for maturity stage of landscape development.The studied watershed is also characterized by a non-circular shaped drainage with rugged and dissected topography that contributes to high flash flood,peak discharge and incidence of soil loss.The result of both models signified that S3 and S4 are highly susceptible to soil erosion.Therefore,these two sub watersheds need priority for soil and water conservation(SWC)measures.Furthermore,the study demonstrated the importance of the integration of different models in the identification of soil erosion prone areas and prioritization for the proper implementation of SWC measures.展开更多
The area of land that is affected by soil erosion in the Yangtze River has been reduced by 146,000 km~2(accounting for 27%of the entire Yangtze River)since 2000.However,the contributions of different tributaries to th...The area of land that is affected by soil erosion in the Yangtze River has been reduced by 146,000 km~2(accounting for 27%of the entire Yangtze River)since 2000.However,the contributions of different tributaries to this soil erosion decline and the underlying causes have not been determined.Here we quantify the soil erosion decline in the Yangtze River and the impacts of the Grain-for-Green Programme(GFGP)and climate change using the RUSLE model and statistical methods.The results were as follows:(1)After the implementation of the GFGP,soil erosion decreased in ten sub-basins excluding the Dongting Lake catchment;(2)Soil erosion was mainly affected by the GFGP and the rainfall erosivity.Specifically,the contributions of the GFGP and rainfall erosivity to soil erosion decline are estimated to be 70.12%and 29.88%,respectively.(3)“Scenario#9”means the combination of slope(15°-25°)of retired farmland converted to shrub land and slope(>25°)of retired farmland converted to grassland.Considering scenario feasibility and management targets,Scenario#9 was the most appropriate land use scenario for the Yangtze River.This study offers insights into managing and reducing soil erosion in the future.展开更多
In China, many scenic and tourism areas are suffering from the urbanization that results from physical development of tourism projects, leading to the removal of the vegetative cover, the creation of areas impermeable...In China, many scenic and tourism areas are suffering from the urbanization that results from physical development of tourism projects, leading to the removal of the vegetative cover, the creation of areas impermeable to water, in-stream modifications, and other problems. In this paper, the risk of soil erosion and its ecological risks in the West Lake Scenic Spots （WLSS） area were quantitatively evaluated by integrating the revised universal soil loss equation （RUSLE） with a digital elevation model （DEM） and geographical information system （GIS） software. The standard RUSLE factors were modified to account for local climatic and topographic characteristics reflected in the DEM maps, and for the soil types and vegetation cover types. An interface was created between the Areinfo software and RUSLE so that the level of soil erosion and its ecological risk in the WLSS area could be mapped immediately once the model factors were defined for the area. The results from an analysis using the Areinfo-RUSLE interface showed that the risk value in 93 % of the expanding western part of the WLSS area was moderate or more severe and the soil erosion risk in this area was thus large compared with that in the rest of the area. This paper mainly aimed to increase the awareness of the soil erosion risk in urbanizing areas and suggest that the local governments should consider the probable ecological risk resulting from soil erosion when enlarging and developing tourism areas.展开更多
In this study,two adjacent gauged catchments on the Chinese Loess Plateau were selected,in which one catchment was afforested and one was restored with natural vegetation in 1954.The distributions of soil erosion rate...In this study,two adjacent gauged catchments on the Chinese Loess Plateau were selected,in which one catchment was afforested and one was restored with natural vegetation in 1954.The distributions of soil erosion rates were estimated between 2010 and 2020 with a high spatial resolution of 2 m in the paired catchments based on the Revised Universal Soil Loss Equation model(RUSLE)and Geographic Information Systems(GIS).The results showed that the simulated soil erosion rates in 2010-2020 averaged 12.58 and 8.56 t ha^(-1)a^(-1)for the grassland and forestland catchment,respectively.Moreover,areas with high soil erosion rates(>80t ha^(-1)a^(-1))were mainly distributed in the topography with steep slope gradients(>45°).Comparisons between simulated soil erosion rates and observed annual sediment loads indicated that the simulation results of the grassland catchment were lower than the observed values,while it was reversed in the forestland catchment.We conclude that the RUSLE model cannot simulate the gravity erosion induced by extreme rainfall events.For the forestland catchment,insufficient streamflow and dense vegetation coverage are crucial factors resulting in hindering the movement of sediments.展开更多
Soil erosion is a prominent environmental problem in karst regions.Exploring the spatiotemporal variability of soil erosion and the factors that influence soil erosion is of great significance for regional soil erosio...Soil erosion is a prominent environmental problem in karst regions.Exploring the spatiotemporal variability of soil erosion and the factors that influence soil erosion is of great significance for regional soil erosion prevention and control.However,the mechanisms influencing the characteristic features of the karst basins,such as bedrock exposure and lithology,still need to be further explored.This study used GIS technology,the Revised Universal Soil Loss Equation model,Getis–Ord Gi*,and partial least squares regression(PLSR)to identify the dominant factors influencing soil erosion and the spatiotemporal variability of soil erosion in 31 sub-basins of the Dabang River Basin(DRB),a typical karst area of Southwest China,from 2010 to 2020.The results indicated that soil erosion in the DRB from 2010 to 2020 was generally decreasing,the mean soil erosion in the DRB in 2010,2015 and 2020 was 18.46,16.51 and 15.29 t ha^(-1)a^(-1),respectively.During the study period,the area of slight erosion increased by 26.39%(706.54 km^(2)),while severe erosion enlarged by 26.36 km^(2).Spatially,the DRB was primarily affected by medium and slight soil erosion.The hot spot areas of soil erosion(key control areas)were mainly concentrated in the central and southern parts of the basin,decreasing each year,and the area of soil erosion hot pots has decreased from 43.22%to 20.60%.PLSR decoupling results show that elevation,bedrock exposure,land use type,interbedded limestone and clastic rock,and vegetation coverage were identified as the key variables affecting soil erosion,explaining 52.8%of soil erosion variability,with a high value of the Variable Importance on Projection(VIP)more than 1.These results can be used as a reference for comprehensive control of soil erosion and water loss in the basin.展开更多
Soil erosion is mainly affected by the rainfall characteristics and land cover conditions,and soil erosion modelling is important for evaluating land degradation status.The revised Universal Soil Loss Equation(RUSLE)h...Soil erosion is mainly affected by the rainfall characteristics and land cover conditions,and soil erosion modelling is important for evaluating land degradation status.The revised Universal Soil Loss Equation(RUSLE)have been widely used to simulate soil loss rate.Previous studies usually considered the general rainfall characteristics and direct effect of runoff with the event rainfall erosivity factor(R_(e))to produce event soil loss(A_(e)),whereas the fluctuation of rainfall intensity within the natural rainfall profile has rarely been considered.In this study,the relative amplitude of rainfall intensity(R_(am))was proposed to generalize the features of rainfall intensity fluctuation under natural rainfall,and it was incorporated in a new R_(e)(R_(e)=R_(am)EI_(30))to develop the RUSLE model considering the fluctuation of rainfall intensity(RUSLE-F).The simulation performance of RUSLE-F model was compared with RUSLE-M1 model(R_(e)=EI_(30))and RUSLE-M2 model(R_(e)=Q_(R)EI_(30))using observations in field plots of grassland,orchard and shrubland during 2011–2016 in a loess hilly catchment of China.The results indicated that the relationship between A_(e) and R_(am)EI_(30) was well described by a power function with higher R2 values(0.82–0.96)compared to Q_(R)EI_(30)(0.80–0.88)and EI_(30)(0.24–0.28).The RUSLE-F model much improved the accuracy in simulating A_(e) with higher NSE(0.55–0.79 vs−0.11∼0.54)and lower RMSE(0.82–1.67 vs 1.04–2.49)than RUSLE-M1 model.Furthermore,the RUSLE-F model had better simulation performance than RUSLE-M2 model under grassland and orchard,and more importantly the rainfall data in the RUSLE-F model can be easily obtained compared to the measurements or estimations of runoff data required by the RUSLE-M2 model.This study highlighted the paramount importance of rainfall intensity fluctuation in event soil loss prediction,and the RUSLE-F model contributed to the further development of USLE/RUSLE family of models.展开更多
Geohazards are a recurrent issue in the Kerio River catchment of Kenya, which usually results in life and property loss. This research focuses on mapping geo-hazard risk zones of the region. The risk zones were develo...Geohazards are a recurrent issue in the Kerio River catchment of Kenya, which usually results in life and property loss. This research focuses on mapping geo-hazard risk zones of the region. The risk zones were developed from a combination of land use land cover maps, agroecological zones maps and soil erosion maps using the Analytical Hierarchy Process method of multi-criteria analysis. The final results depict the geohazard risk maps which show the susceptibility of different areas in the catchment (classified as risk zones) to hazards. The zones range from no risk zones to very high-risk zones. The results showed that the lowlands are most susceptible to hazards as they were classified as high-risk zones. These risk zone areas have impacts on the socio-economic development hence negatively impacting livelihoods in the area.展开更多
Land along the Bomboré River in the rural commune of Mogtédo in Burkina Faso is experiencing degradation. The explanatory causes of this degradation constitute the subject of this study. To do this, a survey...Land along the Bomboré River in the rural commune of Mogtédo in Burkina Faso is experiencing degradation. The explanatory causes of this degradation constitute the subject of this study. To do this, a survey was conducted among agricultural producers deployed along the watercourse. Soil profiles were described and samples were taken to analyze pH, soil organic carbon, soil organic matter, total nitrogen, and texture. The RUSLE model approach based on landstat8 OLI/TIRS and SRTM satellite images dated December 17, 2021 with fairly good radiometric, spatial, and spectral resolution was used to calculate the land loss rate. In terms of results, the potentially irrigable areas that spread out on both sides of the banks of the river cover 209.23 ha with a perimeter of 6.16 km. The number of irrigators is 26 producers and they grow 17.92 ha of vegetables. Soil analyzes indicate the presence of a moderate acid on the vertisol with a pH between 5.57 and 5.86. On the depth 0 - 30 cm of the horizon, the color of the horizons ranges from 5YR4/2 on the talweg and on the right bank to 7.5YR3/2 on the left bank and presents no risk of salinity because the electrical conductivity measured is less than 1dS/cm. The diagnosis of hydromechanical equipment shows that producers use 46 motor pumps for irrigation, of which 15 motor pumps run on gasoline and 31 motor pumps on butane gas with a ratio of 1.7 motor pumps per producer. The number of Polyvinyl Chloride (PVC) pipes used by producers in combination with a motor pump gives an average of 44 per farmer. In terms of mineral fertilization, the gross doses used by producers are 415.53 kg/ha of NPK and 201.55 kg/ha of urea, while the quantities of phytosanitary products are 3.99 l/ha of pesticides and 1.42 l/ha of herbicides. Agricultural activities emit about 222,436.66 kgCO<sub>2</sub>eq into the atmosphere, whose emissions from motor pumps represent 84.52% of these total emissions. The land loss estimate gives an average rate of 2.30 t/ha/year of land loss. This loss is due to the effects of poor agricultural practices, water erosion, and the drainage channels and gullies created by the anarchic installation of dwellings around the edges of the river. This study calls for more monitoring actions to sustainably safeguard the soil and water resources of this river which contribute to the survival of more than 73,214 inhabitants.展开更多
Water erosion is a natural fact in the cycle of shaping the earth’s landforms and the most evident form of land degradation on a planetary scale </span></span><a href="#R20"><span style...Water erosion is a natural fact in the cycle of shaping the earth’s landforms and the most evident form of land degradation on a planetary scale </span></span><a href="#R20"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">(Roose & De Noni, 2004;</span></span></span><span><span></span></span></a><span><span><span style="font-family:"color:#538135;"> </span></span></span><a href="#R08"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Dautrebande & Sohier, 2006;</span></span></span><span><span></span></span></a><span><span><span style="font-family:"color:#538135;"> </span></span></span><a href="#R25"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Toumi et al., 2013;</span></span></span><span><span></span></span></a><span><span><span style="font-family:"color:#538135;"> </span></span></span><a href="#R03"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Azaiez, 2020a)</span></span></span><span><span></span></span></a><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. Its effects have largely affected the rural landscape. Although it is the result of an ancient and primeval climatic and tectonic forcing, man’s footprint in its intensification remains a reality. A real awareness of this problem on the part of scientists is reflected in the many studies on understanding the risks. Experiments have been carried out, equations and models have been developed with the aim of preserving the soil. The watershed of wadi El Badalah, the subject of this study, is not excluded from this risk. The present research is a new comparative contribution to the quantification of soil loss based on four empirical models (Universal Soil Loss Equation USLE, Revised Universal Soil Loss Equation RUSLE, Modified Universal Soil Loss Equation MUSLE and the adjusted model). The main objective of this research project is to test several empirical models of quantification of soil loss, extensively tested on a global scale, to discuss the potential of each model in order to choose the most appropriate for the El Badalah basin. The method is based on geotechnical and geophysical investigations. It consists of determining the anomalies of the subsoil based on the difference in density and the resistivity of the heterogeneous constituents of the subsoil. This is in order to look for sectors potentially favorable to infiltration at the expense of runoff.展开更多
Over the past six decades,the implementation of soil and water conservation measures has significantly reduced soil erosion and sediment yield on the Loess Plateau,China.However,while the overall reduction is well-doc...Over the past six decades,the implementation of soil and water conservation measures has significantly reduced soil erosion and sediment yield on the Loess Plateau,China.However,while the overall reduction is well-documented,the dynamic interplay between soil erosion potential and sediment connectivity,specifically how they spatially covary under land use/cover changes,remains insufficiently understood.To address this gap,this study established a model framework by integrating the revised universal soil loss equation(RUSLE),index of connectivity(IC),and sediment delivery ratio(SDR)to evaluate the spatio-temporal variations in soil erosion and sediment yield in the Hantaichuan Watershed,northern Loess Plateau,China,from 1995 to 2020 and to estimate the effects of land use/cover changes and check dam construction on sediment yield.The results revealed that the soil erosion in the Hantaichuan Watershed decreased by 43.90% from 1995 to 2020 and the sediment yield decreased by 69.28% under the combination of land use/cover changes and check dam construction.The IC and soil erosion(IC-SE)map revealed both the coupling and decoupling covariation relationships between sediment connectivity and soil erosion.By 2020,areas with high connectivity and high erosion(I-E)covered only 18.67% of the watershed,while contributed more than 40.00% to the total erosion.The I-E zones were mainly located in the central part of the watershed where aeolian sands derived from the Hobq Desert are concentrated and were identified as critical areas for soil and water conservation.This study provides support for priority management of watershed conservation measures as well as a valuable reference for future studies.展开更多
Soil erosion poses a great threat to the sustainability of the ecological environment and the harmonious development of human well-being.The revised universal soil loss equation(RUSLE)was used to quantify soil erosion...Soil erosion poses a great threat to the sustainability of the ecological environment and the harmonious development of human well-being.The revised universal soil loss equation(RUSLE)was used to quantify soil erosion in the Three-River Headwaters region(TRH),Qinghai,China from 2000 to 2015.The possible effects of an ecosystem restoration project on soil erosion were explored against the background of climatic changes in the study area.The model was validated with on-ground observations and showed a satisfactory performance,with a multiple correlation coefficient of 0.62 from the linear regression between the estimations and observations.The soil erosion modulus in 2010–2015 increased 6.2%,but decreased 1.2%compared with those in the periods of 2000–2005 and 2005–2010,respectively.Based on the method of overlay analysis,the interannual change of the estimated soil erosion was dominated by climate(about 64%),specifically by precipitation,rather than by vegetation coverage(about 34%).Despite some uncertainties in the model and data,this study quantified the relative contribution of ecological restoration under global climatic change;meanwhile the complexity,labor-intensiveness and long-range character of ecological restoration projects have to be recognized.On-ground observations over the long-term,further parameterization,and data inputs with higher quality are necessary and essential for decreasing the uncertainties in the estimations.展开更多
文摘Soil erosion in the Hare watershed led to significant land degradation,water pollution,and reduced agricultural productivity.Despite its effects,very few researchers have used combined morphometric and RUSLE model techniques to quantify soil erosion and thereby prioritize impacted areas.This work used an automated GIS-based tool(SWPT)to prioritize crucial areas based on topohydrological and morphometric factors and predict soil loss in sub-watersheds using the RUSLE model.Land use/cover data were obtained from Landsat imagery,while slope and morphometric information were extracted from digital elevation data with a resolution of 12.5 m.Soil erodibility was determined using Ethiopian soil maps,and rainfall erosivity was computed using meteorological data.An average annual soil loss of 49 t ha-1 yr-1 was observed in the Hare watershed.Sub-watershed 11 was found to be the most affected,with an average annual soil loss of 85.12 t ha-1 yr-1and a compound parameter value(CPV)of 0.059.Subwatershed 17 has the least amount of soil loss,with 3.67t ha-1 yr-1 and a CPV of 1.32.The study emphasizes the usefulness of integrating RUSLE and morphometric analysis for soil and water conservation planning,suggesting a variety of modeling tools in data-sparse locations to quantify and prioritize erosion-prone areas.
基金supported by the National Natural Science Foundation of China(42377354)the Natural Science Foundation of Hubei province(2024AFB951)the Chunhui Plan Cooperation Research Project of the Chinese Ministry of Education(202200199).
文摘Soil erosion has been recognized as a critical environmental issue worldwide.While previous studies have primarily focused on watershed-scale soil erosion vulnerability from a natural factor perspective,there is a notable gap in understanding the intricate interplay between natural and socio-economic factors,especially in the context of spatial heterogeneity and nonlinear impacts of human-land interactions.To address this,our study evaluates the soil erosion vulnerability at a provincial scale,taking Hubei Province as a case study to explore the combined effects of natural and socio-economic factors.We developed an evaluation index system based on 15 indicators of soil erosion vulnerability:exposure,sensitivity,and adaptability.In addition,the combination weighting method was applied to determine index weights,and the spatial interaction was analyzed using spatial autocorrelation,geographical temporally weighted regression and geographical detector.The results showed an overall decreasing soil erosion intensity in Hubei Province during 2000 and 2020.The soil erosion vulnerability increased before 2000 and then.The areas with high soil erosion vulnerability were mainly confined in the central and southern regions of Hubei Province(Xiantao,Tianmen,Qianjiang and Ezhou)with obvious spatial aggregation that intensified over time.Natural factors(habitat quality index)had negative impacts on soil erosion vulnerability,whereas socio-economic factors(population density)showed substantial spatial variability in their influences.There was a positive correlation between soil erosion vulnerability and erosion intensity,with the correlation coefficients ranging from-0.41 and 0.93.The increase of slope was found to enhance the positive correlation between soil erosion vulnerability and intensity.
基金Chinese Academy of Sciences (CAS)The World Academy of Science (TWAS) for providing financial support
文摘Droughts and soil erosion are among the most prominent climatic driven hazards in drylands,leading to detrimental environmental impacts,such as degraded lands,deteriorated ecosystem services and biodiversity,and increased greenhouse gas emissions.In response to the current lack of studies combining drought conditions and soil erosion processes,in this study,we developed a comprehensive Geographic Information System(GIS)-based approach to assess soil erosion and droughts,thereby revealing the relationship between soil erosion and droughts under an arid climate.The vegetation condition index(VCI)and temperature condition index(TCI)derived respectively from the enhanced vegetation index(EVI)MOD13A2 and land surface temperature(LST)MOD11A2 products were combined to generate the vegetation health index(VHI).The VHI has been conceived as an efficient tool to monitor droughts in the Negueb watershed,southeastern Tunisia.The revised universal soil loss equation(RUSLE)model was applied to quantitatively estimate soil erosion.The relationship between soil erosion and droughts was investigated through Pearson correlation.Results exhibited that the Negueb watershed experienced recurrent mild to extreme drought during 2000–2016.The average soil erosion rate was determined to be 1.8 t/(hm2•a).The mountainous western part of the watershed was the most vulnerable not only to soil erosion but also to droughts.The slope length and steepness factor was shown to be the most significant controlling parameter driving soil erosion.The relationship between droughts and soil erosion had a positive correlation(r=0.3);however,the correlation was highly varied spatially across the watershed.Drought was linked to soil erosion in the Negueb watershed.The current study provides insight for natural disaster risk assessment,land managers,and stake-holders to apply appropriate management measures to promote sustainable development goals in fragile environments.
文摘Soil erosion and the subsequent sedimentation are serious environmental problems.Improper land management coupled with intense rainfall has complicated the problem in the Ethiopian highlands.Consequently,soil loss costs a profound amount of the national GDP and deters land productivity.Quantifying soil loss and prioritizing areas for conservation is imperative for proper planning and resource management.Therefore,this study aimed at estimating the mean annual soil loss rate of Gilgel Abay watershed which has critical implications on Lake Tana and Abbay River(Upper Blue Nile River),using RUSLE and morphometric analysis methods.Datasets including rainfall,soil,Digital Elevation Model and land use/land cover were used to generate important parameters required for the soil loss estimation.Data collected through field observation,consultation with experts and document analysis were used for validation purposes.The results of the study reveal that the watershed experienced an average soil loss rate of 39.8 t ha^(-1)yr^(-1).Subsequently,nearly 25%(37,038 ha)of the watershed is threatened by moderate to very severe soil loss.Among the four sub watersheds,sub watershed 3(S3)and sub watershed 4(S4),which consist of about 65%(105,000 ha)of the total area of the study watershed,experienced an annual soil loss rate of over 30 t ha^(-1)yr^(-1).The amount of soil loss that the study watershed has experienced is above the soil loss tolerance level of Ethiopia(2-18 t ha^(-1)yr^(-1))and the tropical region(10 t ha^(-1)yr^(-1)).Similarly,the results of morphometric analysis showed that the studied watershed has S-shaped hypsometric curve,an indication for maturity stage of landscape development.The studied watershed is also characterized by a non-circular shaped drainage with rugged and dissected topography that contributes to high flash flood,peak discharge and incidence of soil loss.The result of both models signified that S3 and S4 are highly susceptible to soil erosion.Therefore,these two sub watersheds need priority for soil and water conservation(SWC)measures.Furthermore,the study demonstrated the importance of the integration of different models in the identification of soil erosion prone areas and prioritization for the proper implementation of SWC measures.
基金National Natural Science Foundation of China,No.42101259,No.42371101,No.42301455Qin Chuangyuan Cites High-level Innovation or Entrepreneurship Talent Project,No.QCYRCXM-2023-066+2 种基金Fifth Batch Special Funding(Pre-Station)from China Postdoctoral Science Foundation,No.2023TQ0207Fundamental Research Funds for the Central Universities,No.GK202304024,No.1110011297,No.1112010355Teaching Reform Project of Shaanxi University,No.23GGYS-JG06。
文摘The area of land that is affected by soil erosion in the Yangtze River has been reduced by 146,000 km~2(accounting for 27%of the entire Yangtze River)since 2000.However,the contributions of different tributaries to this soil erosion decline and the underlying causes have not been determined.Here we quantify the soil erosion decline in the Yangtze River and the impacts of the Grain-for-Green Programme(GFGP)and climate change using the RUSLE model and statistical methods.The results were as follows:(1)After the implementation of the GFGP,soil erosion decreased in ten sub-basins excluding the Dongting Lake catchment;(2)Soil erosion was mainly affected by the GFGP and the rainfall erosivity.Specifically,the contributions of the GFGP and rainfall erosivity to soil erosion decline are estimated to be 70.12%and 29.88%,respectively.(3)“Scenario#9”means the combination of slope(15°-25°)of retired farmland converted to shrub land and slope(>25°)of retired farmland converted to grassland.Considering scenario feasibility and management targets,Scenario#9 was the most appropriate land use scenario for the Yangtze River.This study offers insights into managing and reducing soil erosion in the future.
基金financial support from the National Natural Science Foundation of China(No.40201021)the Zhejiang Natural Science Foundation of China(M403040).
文摘In China, many scenic and tourism areas are suffering from the urbanization that results from physical development of tourism projects, leading to the removal of the vegetative cover, the creation of areas impermeable to water, in-stream modifications, and other problems. In this paper, the risk of soil erosion and its ecological risks in the West Lake Scenic Spots （WLSS） area were quantitatively evaluated by integrating the revised universal soil loss equation （RUSLE） with a digital elevation model （DEM） and geographical information system （GIS） software. The standard RUSLE factors were modified to account for local climatic and topographic characteristics reflected in the DEM maps, and for the soil types and vegetation cover types. An interface was created between the Areinfo software and RUSLE so that the level of soil erosion and its ecological risk in the WLSS area could be mapped immediately once the model factors were defined for the area. The results from an analysis using the Areinfo-RUSLE interface showed that the risk value in 93 % of the expanding western part of the WLSS area was moderate or more severe and the soil erosion risk in this area was thus large compared with that in the rest of the area. This paper mainly aimed to increase the awareness of the soil erosion risk in urbanizing areas and suggest that the local governments should consider the probable ecological risk resulting from soil erosion when enlarging and developing tourism areas.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB40000000)the National Natural Science Foundation of China(Grant No.41790444)。
文摘In this study,two adjacent gauged catchments on the Chinese Loess Plateau were selected,in which one catchment was afforested and one was restored with natural vegetation in 1954.The distributions of soil erosion rates were estimated between 2010 and 2020 with a high spatial resolution of 2 m in the paired catchments based on the Revised Universal Soil Loss Equation model(RUSLE)and Geographic Information Systems(GIS).The results showed that the simulated soil erosion rates in 2010-2020 averaged 12.58 and 8.56 t ha^(-1)a^(-1)for the grassland and forestland catchment,respectively.Moreover,areas with high soil erosion rates(>80t ha^(-1)a^(-1))were mainly distributed in the topography with steep slope gradients(>45°).Comparisons between simulated soil erosion rates and observed annual sediment loads indicated that the simulation results of the grassland catchment were lower than the observed values,while it was reversed in the forestland catchment.We conclude that the RUSLE model cannot simulate the gravity erosion induced by extreme rainfall events.For the forestland catchment,insufficient streamflow and dense vegetation coverage are crucial factors resulting in hindering the movement of sediments.
基金supported by National Natural Science Foundation of China(32060372,32360421)Guizhou Science and Technology Department(Qian Ke He Ji Chu ZK-[2023]Key 029Qiankehe Zhicheng[2021]Yiban462)。
文摘Soil erosion is a prominent environmental problem in karst regions.Exploring the spatiotemporal variability of soil erosion and the factors that influence soil erosion is of great significance for regional soil erosion prevention and control.However,the mechanisms influencing the characteristic features of the karst basins,such as bedrock exposure and lithology,still need to be further explored.This study used GIS technology,the Revised Universal Soil Loss Equation model,Getis–Ord Gi*,and partial least squares regression(PLSR)to identify the dominant factors influencing soil erosion and the spatiotemporal variability of soil erosion in 31 sub-basins of the Dabang River Basin(DRB),a typical karst area of Southwest China,from 2010 to 2020.The results indicated that soil erosion in the DRB from 2010 to 2020 was generally decreasing,the mean soil erosion in the DRB in 2010,2015 and 2020 was 18.46,16.51 and 15.29 t ha^(-1)a^(-1),respectively.During the study period,the area of slight erosion increased by 26.39%(706.54 km^(2)),while severe erosion enlarged by 26.36 km^(2).Spatially,the DRB was primarily affected by medium and slight soil erosion.The hot spot areas of soil erosion(key control areas)were mainly concentrated in the central and southern parts of the basin,decreasing each year,and the area of soil erosion hot pots has decreased from 43.22%to 20.60%.PLSR decoupling results show that elevation,bedrock exposure,land use type,interbedded limestone and clastic rock,and vegetation coverage were identified as the key variables affecting soil erosion,explaining 52.8%of soil erosion variability,with a high value of the Variable Importance on Projection(VIP)more than 1.These results can be used as a reference for comprehensive control of soil erosion and water loss in the basin.
基金supported by the National Natural Science Foundation of China(nos.U2243231,42041004 and 42201126)the Doctoral Foundation of Tianjin Normal University(no.52XB1910)the Youth Innovation Promotion Association CAS(no.Y202013)。
文摘Soil erosion is mainly affected by the rainfall characteristics and land cover conditions,and soil erosion modelling is important for evaluating land degradation status.The revised Universal Soil Loss Equation(RUSLE)have been widely used to simulate soil loss rate.Previous studies usually considered the general rainfall characteristics and direct effect of runoff with the event rainfall erosivity factor(R_(e))to produce event soil loss(A_(e)),whereas the fluctuation of rainfall intensity within the natural rainfall profile has rarely been considered.In this study,the relative amplitude of rainfall intensity(R_(am))was proposed to generalize the features of rainfall intensity fluctuation under natural rainfall,and it was incorporated in a new R_(e)(R_(e)=R_(am)EI_(30))to develop the RUSLE model considering the fluctuation of rainfall intensity(RUSLE-F).The simulation performance of RUSLE-F model was compared with RUSLE-M1 model(R_(e)=EI_(30))and RUSLE-M2 model(R_(e)=Q_(R)EI_(30))using observations in field plots of grassland,orchard and shrubland during 2011–2016 in a loess hilly catchment of China.The results indicated that the relationship between A_(e) and R_(am)EI_(30) was well described by a power function with higher R2 values(0.82–0.96)compared to Q_(R)EI_(30)(0.80–0.88)and EI_(30)(0.24–0.28).The RUSLE-F model much improved the accuracy in simulating A_(e) with higher NSE(0.55–0.79 vs−0.11∼0.54)and lower RMSE(0.82–1.67 vs 1.04–2.49)than RUSLE-M1 model.Furthermore,the RUSLE-F model had better simulation performance than RUSLE-M2 model under grassland and orchard,and more importantly the rainfall data in the RUSLE-F model can be easily obtained compared to the measurements or estimations of runoff data required by the RUSLE-M2 model.This study highlighted the paramount importance of rainfall intensity fluctuation in event soil loss prediction,and the RUSLE-F model contributed to the further development of USLE/RUSLE family of models.
文摘Geohazards are a recurrent issue in the Kerio River catchment of Kenya, which usually results in life and property loss. This research focuses on mapping geo-hazard risk zones of the region. The risk zones were developed from a combination of land use land cover maps, agroecological zones maps and soil erosion maps using the Analytical Hierarchy Process method of multi-criteria analysis. The final results depict the geohazard risk maps which show the susceptibility of different areas in the catchment (classified as risk zones) to hazards. The zones range from no risk zones to very high-risk zones. The results showed that the lowlands are most susceptible to hazards as they were classified as high-risk zones. These risk zone areas have impacts on the socio-economic development hence negatively impacting livelihoods in the area.
文摘Land along the Bomboré River in the rural commune of Mogtédo in Burkina Faso is experiencing degradation. The explanatory causes of this degradation constitute the subject of this study. To do this, a survey was conducted among agricultural producers deployed along the watercourse. Soil profiles were described and samples were taken to analyze pH, soil organic carbon, soil organic matter, total nitrogen, and texture. The RUSLE model approach based on landstat8 OLI/TIRS and SRTM satellite images dated December 17, 2021 with fairly good radiometric, spatial, and spectral resolution was used to calculate the land loss rate. In terms of results, the potentially irrigable areas that spread out on both sides of the banks of the river cover 209.23 ha with a perimeter of 6.16 km. The number of irrigators is 26 producers and they grow 17.92 ha of vegetables. Soil analyzes indicate the presence of a moderate acid on the vertisol with a pH between 5.57 and 5.86. On the depth 0 - 30 cm of the horizon, the color of the horizons ranges from 5YR4/2 on the talweg and on the right bank to 7.5YR3/2 on the left bank and presents no risk of salinity because the electrical conductivity measured is less than 1dS/cm. The diagnosis of hydromechanical equipment shows that producers use 46 motor pumps for irrigation, of which 15 motor pumps run on gasoline and 31 motor pumps on butane gas with a ratio of 1.7 motor pumps per producer. The number of Polyvinyl Chloride (PVC) pipes used by producers in combination with a motor pump gives an average of 44 per farmer. In terms of mineral fertilization, the gross doses used by producers are 415.53 kg/ha of NPK and 201.55 kg/ha of urea, while the quantities of phytosanitary products are 3.99 l/ha of pesticides and 1.42 l/ha of herbicides. Agricultural activities emit about 222,436.66 kgCO<sub>2</sub>eq into the atmosphere, whose emissions from motor pumps represent 84.52% of these total emissions. The land loss estimate gives an average rate of 2.30 t/ha/year of land loss. This loss is due to the effects of poor agricultural practices, water erosion, and the drainage channels and gullies created by the anarchic installation of dwellings around the edges of the river. This study calls for more monitoring actions to sustainably safeguard the soil and water resources of this river which contribute to the survival of more than 73,214 inhabitants.
文摘Water erosion is a natural fact in the cycle of shaping the earth’s landforms and the most evident form of land degradation on a planetary scale </span></span><a href="#R20"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">(Roose & De Noni, 2004;</span></span></span><span><span></span></span></a><span><span><span style="font-family:"color:#538135;"> </span></span></span><a href="#R08"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Dautrebande & Sohier, 2006;</span></span></span><span><span></span></span></a><span><span><span style="font-family:"color:#538135;"> </span></span></span><a href="#R25"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Toumi et al., 2013;</span></span></span><span><span></span></span></a><span><span><span style="font-family:"color:#538135;"> </span></span></span><a href="#R03"><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">Azaiez, 2020a)</span></span></span><span><span></span></span></a><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">. Its effects have largely affected the rural landscape. Although it is the result of an ancient and primeval climatic and tectonic forcing, man’s footprint in its intensification remains a reality. A real awareness of this problem on the part of scientists is reflected in the many studies on understanding the risks. Experiments have been carried out, equations and models have been developed with the aim of preserving the soil. The watershed of wadi El Badalah, the subject of this study, is not excluded from this risk. The present research is a new comparative contribution to the quantification of soil loss based on four empirical models (Universal Soil Loss Equation USLE, Revised Universal Soil Loss Equation RUSLE, Modified Universal Soil Loss Equation MUSLE and the adjusted model). The main objective of this research project is to test several empirical models of quantification of soil loss, extensively tested on a global scale, to discuss the potential of each model in order to choose the most appropriate for the El Badalah basin. The method is based on geotechnical and geophysical investigations. It consists of determining the anomalies of the subsoil based on the difference in density and the resistivity of the heterogeneous constituents of the subsoil. This is in order to look for sectors potentially favorable to infiltration at the expense of runoff.
基金supported by the National Natural Science Foundation of China(42077076,42177323)the National Natural Science Foundation of China and Yellow River Water Science Research Joint Fund(U2243211).
文摘Over the past six decades,the implementation of soil and water conservation measures has significantly reduced soil erosion and sediment yield on the Loess Plateau,China.However,while the overall reduction is well-documented,the dynamic interplay between soil erosion potential and sediment connectivity,specifically how they spatially covary under land use/cover changes,remains insufficiently understood.To address this gap,this study established a model framework by integrating the revised universal soil loss equation(RUSLE),index of connectivity(IC),and sediment delivery ratio(SDR)to evaluate the spatio-temporal variations in soil erosion and sediment yield in the Hantaichuan Watershed,northern Loess Plateau,China,from 1995 to 2020 and to estimate the effects of land use/cover changes and check dam construction on sediment yield.The results revealed that the soil erosion in the Hantaichuan Watershed decreased by 43.90% from 1995 to 2020 and the sediment yield decreased by 69.28% under the combination of land use/cover changes and check dam construction.The IC and soil erosion(IC-SE)map revealed both the coupling and decoupling covariation relationships between sediment connectivity and soil erosion.By 2020,areas with high connectivity and high erosion(I-E)covered only 18.67% of the watershed,while contributed more than 40.00% to the total erosion.The I-E zones were mainly located in the central part of the watershed where aeolian sands derived from the Hobq Desert are concentrated and were identified as critical areas for soil and water conservation.This study provides support for priority management of watershed conservation measures as well as a valuable reference for future studies.
基金National Key Research and Development Program of China(2016YFC0500203)Science and Technology Program of Qinghai Province(2018-ZJ-T09,2017-SF-A6)
文摘Soil erosion poses a great threat to the sustainability of the ecological environment and the harmonious development of human well-being.The revised universal soil loss equation(RUSLE)was used to quantify soil erosion in the Three-River Headwaters region(TRH),Qinghai,China from 2000 to 2015.The possible effects of an ecosystem restoration project on soil erosion were explored against the background of climatic changes in the study area.The model was validated with on-ground observations and showed a satisfactory performance,with a multiple correlation coefficient of 0.62 from the linear regression between the estimations and observations.The soil erosion modulus in 2010–2015 increased 6.2%,but decreased 1.2%compared with those in the periods of 2000–2005 and 2005–2010,respectively.Based on the method of overlay analysis,the interannual change of the estimated soil erosion was dominated by climate(about 64%),specifically by precipitation,rather than by vegetation coverage(about 34%).Despite some uncertainties in the model and data,this study quantified the relative contribution of ecological restoration under global climatic change;meanwhile the complexity,labor-intensiveness and long-range character of ecological restoration projects have to be recognized.On-ground observations over the long-term,further parameterization,and data inputs with higher quality are necessary and essential for decreasing the uncertainties in the estimations.
