A large number of loose piles formed by mountain hazards are highly susceptible to hydraulic erosion under rainfall conditions.The use of ecological substrate materials for erosion control and ecological restoration o...A large number of loose piles formed by mountain hazards are highly susceptible to hydraulic erosion under rainfall conditions.The use of ecological substrate materials for erosion control and ecological restoration of gravel soil slopes has become a current research hotspot and the study difficulty.The post-earthquake slump accumulation gravel soil in Jiuzhaigou was selected as the research object,and the self-developed modified glutinous rice-based material was used to reinforce the gravel soil.The variable slope flume erosion test and rainfall simulation test were carried out to study the water erosion resistance of the material reconstructed soil under the influence of runoff erosion and raindrop splash erosion.The results show that:As the material content reached 12.5%,the reconstructed soil did not disintegrate after 24 hours of immersion,the internal friction angle was increased by 42.26%,and the cohesion was increased by 235.5%,which played a significant reinforcement effect.In the process of slope erosion,the soil rill erodibility parameter Kr was only 3‰ of the gravel soil control group,the critical shear force τ increased by 272%,and the soil erosion resistance was significantly improved.In the process of rainfall and rainfall on the slope,the runoff intensity of the reconstructed soil was stable,and the ability to resist runoff erosion and raindrop splash erosion was enhanced.The maximum value of soil loss rate on different slope slopes is 0.02-0.10 g·m^(-2)s^(-1),which is significantly lower than that of the control group and has better erosion reduction effect.展开更多
Wind and water erosion are among the most important causes of soil loss, and understanding their interactions is important for estimating soil quality and environmental impacts in regions where both types of erosion o...Wind and water erosion are among the most important causes of soil loss, and understanding their interactions is important for estimating soil quality and environmental impacts in regions where both types of erosion occur. We used a wind tunnel and simulated rainfall to study sediment yield, particle-size distribution and the fractal dimension of the sediment particles under wind and water erosion. The experiment was conducted with wind ero- sion firstly and water erosion thereafter, under three wind speeds (0, 11 and 14 m/s) and three rainfall intensities (60, 80 and 100 ram/h). The results showed that the sediment yield was positively correlated with wind speed and rain- fall intensity (P〈0.01). Wind erosion exacerbated water erosion and increased sediment yield by 7.25%-38.97% relative to the absence of wind erosion. Wind erosion changed the sediment particle distribution by influencing the micro-topography of the sloping land surface. The clay, silt and sand contents of eroded sediment were also posi- tively correlated with wind speed and rainfall intensity (P〈0.01). Wind erosion increased clay and silt contents by 0.35%-19.60% and 5.80%-21.10%, respectively, and decreased sand content by 2.40%-8.33%, relative to the absence of wind erosion. The effect of wind erosion on sediment particles became weaker with increasing rainfall intensities, which was consistent with the variation in sediment yield. However, particle-size distribution was not closely correlated with sediment yield (P〉0.05). The fractal dimension of the sediment particles was significantly different under different intensities of water erosion (P〈0.05), but no significant difference was found under wind and water erosion. The findings reported in this study implicated that both water and wind erosion should be controlled to reduce their intensifying effects, and the controlling of wind erosion could significantly reduce water erosion in this wind-water erosion crisscross region.展开更多
Soils in the hydro-fluctuation belts of the reservoirs are most highly influenced by the special hydro-conditions and reservoir operation,leading to unique soil erosion process and largely accelerate soil erosion inte...Soils in the hydro-fluctuation belts of the reservoirs are most highly influenced by the special hydro-conditions and reservoir operation,leading to unique soil erosion process and largely accelerate soil erosion intensity.The present study aimed to estimate soil erosion rate in the hydro-fluctuation belt of the Pubugou Reservoir,Southwest China,based on the framework of Universal Soil Loss Equation(USLE).An attempt has been made to modify the original USLE by including the reservoir water erosivity(W),a new factor into the model.Soil erosion rate from different land use types were quantitatively estimated,using the USLE and the modified USLE respectively.Field observation showed that soil erosion rate in dry farmland,bare land and grassland was 4700,44600 and 5050 t/km2,respectively.The erosion rate assessed by the modified USLE was closely related to that recorded from the field monitoring data.The findings of this study clearly highlight the importance of inclusion of the W factor to the original USLE model while assessing soil erosion in the reservoir hydro-fluctuation belt.展开更多
Complex erosion by wind and water, which is also called aeolian-fluvial interactions, is an important erosion process and landscape in arid and semiarid regions. The effectiveness of links between wind and water proce...Complex erosion by wind and water, which is also called aeolian-fluvial interactions, is an important erosion process and landscape in arid and semiarid regions. The effectiveness of links between wind and water process, spatial environmental transitions and temporal environmental change are the three main driving forces determining the geomorphologic significance of aeolian-fluvial interactions. As a complex interrelating and intercoupling system, complex erosion by wind and water has spatial- temporal variation features. The process of complex erosion by wind and water can be divided into palaeoenvironmental process and contemporary process. Early work in drylands has often been attributed to one of two schools advocating either an 'aeolianist' or a 'fluvialist' perspective, so it was not until the 1930s that the research on complex erosion by wind and water had been conducted. There are two obstacles restricting the research of complex erosion by wind and water. Firstly, how to transform in different temporal and spatial scales is still unsettled; and secondly, the research methodology is still immature. In the future, the mechanism and control of erosion, the complex soil erodibility in wind and water erosion will be the focus of research on complex erosion by wind and water.展开更多
Both tillage erosion and water erosion are severe erosional forms that occur widely on sloping agricultural land.However,previous studies have rarely considered the process of landform change due to continuous simulat...Both tillage erosion and water erosion are severe erosional forms that occur widely on sloping agricultural land.However,previous studies have rarely considered the process of landform change due to continuous simulation experiments of alternating tillage erosion and water erosion.To identify such changes,we applied a scouring experiment(at a 60 L min-1 water discharge rate based on precipitation data from the local meteorological station and the catchment area in the Yuanmou County,Yunnan Province,China)and a series of simulated tillage experiments where plots were consecutively tilled 5,10,and 15 times in rotation(representing 5 yr,10 yr,and 15 yr of tillage)at slope gradients of 5°,10°,and 20°.Close-range photogrammetry(CRP)employing an unmanned aerial vehicle(UAV)and a real-time kinematic global positioning system(RTK-GPS)was used to measure landform changes,and highresolution digital elevation models(DEMs)were generated to calculate net soil loss volumes.Additionally,the CRP was determined to be accurate and applicable through the use of erosion pins.The average tillage erosion rates were 69.85,131.45,and 155.34 t·hm-2·tillage pass-1,and the average water erosion rates were 1892.52,2961.76,and 4405.93 t·hm-2·h-1 for the 5°,10°,and 20°sloping farmland plots,respectively.The water erosion rates increased as tillage intensity increased,indicating that tillage erosion accelerates water erosion.Following these intensive tillage treatments,slope gradients gradually decreased,while the trend in slope gradients increased in runoff plots at the conclusion of the scouring experiment.Compared to the original plots(prior to our experiments),interactions between tillage and water erosion caused no obvious change in the landform structure of the runoff plots,while the height of all the runoff plots decreased.Our findings showed that both tillage erosion and water erosion caused a pseudo-steady-state landform evolutionary mechanism and resulted in thin soil layers on cultivated land composed of purple soil in China.展开更多
In semi-arid regions, complex erosion resulted from a combination of wind and water actions has led to a massive soil loss and a comprehensive understanding of its mechanism is the first step toward prevention of the ...In semi-arid regions, complex erosion resulted from a combination of wind and water actions has led to a massive soil loss and a comprehensive understanding of its mechanism is the first step toward prevention of the erosion. However, the mutual influences between wind erosion and water erosion have not been fully understood. This research used a wind tunnel and two rainfall simulators and simulated two rounds of alternations between wind erosion and water erosion(i.e., 1^(st) wind erosion–1^(st) water erosion and 2^(nd) wind erosion–2^(nd) water erosion) on three slopes(5°, 10°, and 15°) with six wind speeds(0, 9, 11, 13, 15, and 20 m/s) and five rainfall intensities(0, 30, 45, 60, and 75 mm/h). The objective was to analyze the influences of wind erosion on succeeding water erosion. Results showed that the effects of wind erosion on water erosion were not the same in the two rounds of tests. In the 1^(st) round of tests, wind erosion first restrained and then intensified water erosion mostly because the blocking effect of wind-sculpted micro-topography on surface flow was weakened with the increase in slope. In the 2^(nd) round of tests, wind erosion intensified water erosion on beds with no rills at gentle slopes and low rainfall intensities or with large-size rills at steep slopes and high rainfall intensities. Wind erosion restrained water erosion on beds with small rills at moderate slopes and moderate rainfall intensities. The effects were mainly related to the fine grain layer, rills and slope of the original bed in the 2^(nd) round of tests. The findings can deepen our understanding of complex erosion resulted from a combination of wind and water actions and provide scientific references to regional soil and water conservation.展开更多
To quantify water erosion rates and annual soil loss in mountainous areas,two different empirical models were used to estimate the effects of soil erosion in a small mountain basin,the Guerna Creek watershed,located i...To quantify water erosion rates and annual soil loss in mountainous areas,two different empirical models were used to estimate the effects of soil erosion in a small mountain basin,the Guerna Creek watershed,located in the Central Southern Alps(Northern Italy).These two models,Revised Universal Soil Loss Equation(RUSLE) and Erosion Potential Model(EPM),were implemented in a Geographical Information System,accounting for the geographical,geomorphological,and weather-climate parameters,which are fundamental to evaluating the intensity and variability of the erosive processes.Soil characterization was supported by laboratory analysis.The results(computed soil loss of 87 t/ha/year and 11.1 m^(3)/ha/year,using RUSLE equation and EPM method,respectively,and sediment yield of 7.5 m^(3)/ha/year using EPM method) were compared to other studies reported in the literature for different case studies with similar topographic and climatic features,as well as to those provided by the European Soil Data Centre(ESDAC).In both cases,the agreement was satisfactory,showing consistency of the adopted procedures to the parametrization of the physical processes.展开更多
The watershed of the Arbaa Ayacha River is an environment favorable to the development of the phenomena of water erosion as a result of its topographic features, lithological and climate. Therefore it has been the sub...The watershed of the Arbaa Ayacha River is an environment favorable to the development of the phenomena of water erosion as a result of its topographic features, lithological and climate. Therefore it has been the subject of evaluation of states erosive and of different causal factors of the risk of erosion by adaptation of cross-matrices based on directives PAP/RAC (Priority Actions Programme/Regional Activity Centre) [1]. This method is based on three approaches. The predictive approach provides a synthetic map of the distribution of the erosive states, with 51% of the basin subjected to high risks. The descriptive mapping of the various forms of erosion shows an enormous extension of stripping and sheet erosion (91%), superficial gullies and moderately deep gullies are growing in view of the gathering of runoffs from upstream to the downstream. The superposition of the results of both predictive and descriptive approaches gives a consolidated map PAP/RAC whose analysis shows that soils’ loss throughout the basin is proportional to the increase of the major factors of water erosion according to the level of importance: The topographical factor—soil types—slope-lithology following a positive linear relationship, while the order of the parameters that are negative linear relationship is density of vegetation cover-land cover [2]. This same map gives maximal losses corresponding mainly to friable lithologic natural areas of badlands at the center of the basin which correspond to Tensift’s terraces [3]. In the downstream basin, the combined effect of deep ravines and banks sapements promotes high risk while in the upstream, the localized solifluxions and gravity screens participate in serious losses.展开更多
Soil erosion is one of the most serious environmental issues constraining the sustainable development of human society and economies.Soil compound erosion is the result of the alternation or interaction between two or...Soil erosion is one of the most serious environmental issues constraining the sustainable development of human society and economies.Soil compound erosion is the result of the alternation or interaction between two or more erosion forces.In recent years,fluctuations and extreme changes in climatic factors(air temperature,precipitation,wind speed,etc.)have led to an increase in the intensity and extent of compound erosion,which is increasingly considered in soil erosion research.First,depending on the involvement of gravity,compound erosion process can be divided into compound erosion with and without gravity.We systematically summarized the research on the mechanisms and processes of alternating or interacting soil erosion forces(wind,water,and freeze-thaw)considering different combinations,combed the characteristics of compound erosion in three typical regions,namely,high-elevation areas,high-latitude areas,and dry and wet transition regions,and reviewed soil compound erosion research methods,such as station observations,simulation experiments,prediction models,and artificial neural networks.The soil erosion model of wind,water,and freeze-thaw interaction is the most significant method for quantifying and predicting compound erosion.Furthermore,it is proposed that there are several issues such as unclear internal mechanisms,lack of comprehensive prediction models,and insufficient scale conversion methods in soil compound erosion research.It is also suggested that future soil compound erosion mechanism research should prioritize the coupling of compound erosion forces and climate change.展开更多
As an important parameter in the soil erosion model, soil surface roughness(SSR) is used to quantitatively describe the micro-relief on agricultural land. SSR has been extensively studied both experimentally and the...As an important parameter in the soil erosion model, soil surface roughness(SSR) is used to quantitatively describe the micro-relief on agricultural land. SSR has been extensively studied both experimentally and theoretically; however, no studies have focused on understanding SSR on the Loess Plateau of China. This study investigated changes in SSR for three different tillage practices on the Loess Plateau of China and the effects of SSR on runoff and erosion yield during simulated rainfall. The tillage practices used were zero tillage(ZT), shallow hoeing(SH) and contour ploughing(CP). Two rainfall intensities were applied, and three stages of water erosion processes(splash erosion(I), sheet erosion(II) and rill erosion(III)) were analyzed for each rainfall intensity. The chain method was used to measure changes in SSR both initially and after each stage of rainfall. A splash board was used to measure the splash erosion at stage I. Runoff and sediment data were collected continuously at 2-min intervals during rainfall erosion stages II and III. We found that SSR of the tilled surfaces ranged from 1.0% to 21.9% under the three tillage practices, and the order of the initial SSR for the three treatments was ZT〈SH〈CP. For the ZT treatment, SSR increased slightly from stage I to III, whereas for the SH and CP treatments, SSR decreased by 44.5% and 61.5% after the three water erosion stages, respectively, and the greatest reduction in SSR occurred in stage I. Regression analysis showed that the changes in SSR with increasing cumulative rainfall could be described by a power function(R2〉0.49) for the ZT, SH and CP treatments. The runoff initiation time was longer in the SH and CP treatments than in the ZT treatment. There were no significant differences in the total runoff yields among the ZT, SH and CP treatments. Sediment loss was significantly smaller(P〈0.05) in the SH and CP treatments than in the ZT treatment.展开更多
Climate,land use and land cover(LULC)changes are among the primary driving forces of soil loss.Decoupling their effects can help in understanding the magnitude and trend of soil loss in response to human activities an...Climate,land use and land cover(LULC)changes are among the primary driving forces of soil loss.Decoupling their effects can help in understanding the magnitude and trend of soil loss in response to human activities and ecosystem management.Here,the RUSLE model was applied to estimate the spatial-temporal variations of soil loss rate in the Three Gorges Reservoir(TGR)area during 2001-2015,followed by a scenario design to decouple the effects of climate and LULC changes.The results showed that increasing rainfall generated as much as 2.90×10^(7)t soil loss in the TGR area.However,such effect was offset by changes in LULC particularly afforestation,which retained about 1.10×10^(7)t soil annually.Other human activities such as dam development and urbanization aggravated soil loss by as much as 1.40×10^(6)t annually.Because of land use policies that favor economic development,distinct spatial variances of soil loss were observed in TGR area.Soil loss in some counties located downstream of the TGR area(i.e.,close to the dam)was more influenced by dam development,but soil loss in the other counties was more influenced by urbanization.As climate change(i.e.,increasing rainfall)did not affect plant performance in TGR area,our findings suggested that ecological restoration was more beneficial to curb the amount of soil loss caused by urbanization and dam construction.展开更多
The Pisha sandstone-coverd area is among the regions that suffer from the most severe water loss and soil erosion in China and is the main source of coarse sand for the Yellow River. This study demonstrated a new eros...The Pisha sandstone-coverd area is among the regions that suffer from the most severe water loss and soil erosion in China and is the main source of coarse sand for the Yellow River. This study demonstrated a new erosion control method using W-OH solution, a type of hydrophilic polyurethane, to prevent the Pisha sandstone from water erosion. We evaluated the comprehensive effects of W-OH on water erosion resistance and vegetation-growth promotion through simulated scouring tests and field demonstrations on the Ordos Plateau of China. The results of simulated scouring tests show that the water erosion resistance of W-OH treated area was excellent and the cumulative sediment yield reduction reached more than 99%. In the field demonstrations, the vegetation coverage reached approximately 95% in the consolidation-green area, and there was almost no shallow trenches on the entire slope in the treated area. In comparison, the control area experienced severe erosion with deep erosion gullies appeared on the slope and the vegetation coverage was less than 30%. This study illustrated that W-OH treatment can protect the Pisha sandstone from erosion and provide the vegetation seeds a chance to grow. Once the vegetation matured, the effects of consolidation-growth mutual promotion can efficiently and effectively improve the water erosion resistance and ecological restoration.展开更多
Loess Plateau, an arid and semi arid region in Northwest China, is well known for its most serious soil erosion in terms of sediment yield each year. Soil erosion, which is intensified by agricultural activities, is...Loess Plateau, an arid and semi arid region in Northwest China, is well known for its most serious soil erosion in terms of sediment yield each year. Soil erosion, which is intensified by agricultural activities, is the major factor influencing sustainable agriculture development in this region. It reduces productivity by removing nutrients and especially reducing water availability that is essential for crop production in the area. It also brings about off site costs by demanding more efforts for maintenance of banks and dams along Yellow River through raising the riverbed with sediment. Climate is capricious and extreme weather conditions occur frequently, which impairs normal agricultural production with erosion and also decrease of water availability. Extensive way of farming still dominates on the Loess Plateau, which cannot produce satisfying economic results and needs to be improved or altered. Conventional agricultural production pattern needs to be reconsidered for husbandry has not been granted its due position. Agriculture is the backbone of economy. Poor agricultural production impedes economic development and vice versa, backward economy also influences the advancement of agriculture. Besides a large population, education status of farmers is another threshold that requires being resolved for a sustainable agriculture. Although conventional agriculture has been practiced there for more than 5000 years, now it cannot meet the demand for food and fiber by the increasing population and some of its farming practices are contributing to environmental degradation directly or indirectly and can sustain no longer. Agriculture on Loess Plateau needs to find its own way of sustainability. To work toward a sustainable agriculture, chances and challenges both indwell on Loess Plateau.展开更多
The soils of Benin in general and those of the department of Zou, in particular, are highly degraded. This study aimed to evaluate the effectiveness of sustainable land management practices on soil erodibility in two ...The soils of Benin in general and those of the department of Zou, in particular, are highly degraded. This study aimed to evaluate the effectiveness of sustainable land management practices on soil erodibility in two villages in the Plateau of Abomey. Soil samples were collected on plots under Sustainable Land Management (SLM) measures (direct seeding, maize residue management and soybean-cereal rotation) and on their adjacent control. The soil samples were prepared and analyzed in laboratory to determine variables such as soil permeability, organic matter content, and particle size. Soil erodibility was determined as proposed by Wischmeier & Smith. The effect of SLM practices was significant (0.02) on soil permeability. On plots under SLM measurements, soil permeability is higher with an average of 93.97 mm/h at Folly and 82.43 mm/h at Hanagbo. SLM measurements significantly (0.04) added organic matter to the soil. The average organic matter of the plots under SLM measures in Folly varies from 0.73% to 1.39% while it varies from 0.49% to 0.73% in the control plots. In Hanagbo, the average organic matter of the plots under SLM measures varies from 1.86% to 2.48% against 1.41% to 1.66% for the control plots. Regarding soil erodibility, it was found that the influence of SLM measures is significant in both villages. In villages, direct seeding and maize residue management significantly (0.008) reduced soil erodibility compared to their adjacent controls, while the soybean-cereal rotation measure increased soil erodibility compared to plot witnesses. The average soil erodibility of plots under SLM measures varies by 0.21 t⋅h/Mj⋅mm at 0.38 t⋅h/Mj⋅mm in the village of Hanagbo and 0.25 t⋅h/Mj⋅mm at 0.38 t⋅h/Mj⋅mm in the village of Folly. It varies from 0.24 t⋅h/Mj⋅mm at 0.28 t⋅h/Mj⋅mm for the control plots at Hanagbo and 0.31 t⋅h/Mj⋅mm at 0.37 t⋅h/Mj⋅mm in Folly. These practices can therefore be used for the sustainable use of agricultural land.展开更多
To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and quantified.It is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(...To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and quantified.It is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(2)at the basin scale,which encompasses the entire hydrological process.This study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin scale.Applying this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1980-2020 was 1.33×10^(8)t,displaying a decreasing trend followed by a slight increase.Only 12% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the basin.The average lateral soil organic carbon loss induced by erosion was 8.86×10^(11)g C in 1980 and 1.50×10^(11)g C in 2020,with a decline rate of 83%.A net land sink for atmospheric CO_(2)of 5.54×1011g C a^(-1)occurred during erosion,primarily through sediment burial and dynamic replacement.However,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon removal.Moreover,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long timeframes.Consequently,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.展开更多
Located in the inland arid area of Central Asia and northwest China,Xinjiang has recently received heightened concerns over soil water erosion,which is highly related with the sustainable utilization of barren soil an...Located in the inland arid area of Central Asia and northwest China,Xinjiang has recently received heightened concerns over soil water erosion,which is highly related with the sustainable utilization of barren soil and limited water resources.Data from the national soil erosion survey of China(1985-2011)and Xinjiang statistical yearbook(2000-2010)was used to analyze the trend,intensity,and serious soil water erosion regions.Results showed that the water erosion area in Xinjiang was 87.6103 km^(2) in 2011,mainly distributed in the Ili river valley and the northern and southern Tian Mountain.Soil erosion gradient was generally slight and the average erosion modulus was 2184 t/(km^(2) a).During the last 26 years,the water erosion area in Xinjiang decreased by 23.2%,whereas the intensity was still increasing.The driving factors from large to small impact included:population boom and human activities4vegetation degradation4rainfall and climate change4topography and soil erodibility4tectonics movement.Soil water erosion resulted in eco-environmental and socioeconomic losses,such as destroying farmland and grassland,triggering floods,sedimentation of reservoirs,damaging transportation and irrigation facilities,and aggravating poverty.A landscape ecological design approach is suggested for integrated control of soil erosion.Currently,an average of 2.07×10^(3) km^(2) of formerly eroded area is conserved each year.This study highlighted the importance and longevity of soil and water conservation efforts in Xinjiang,and offered some suggestions on ecological restoration and combating desertification in arid regions of Central Asia.&2015 International Research and Training Center on Erosion and Sedimentation and China Water and Power Press.Production and Hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).展开更多
Water erosion process induces differences to the nitrogen(N)functional microbial community structure,which is the driving force to key N processes at soil-water interface.However,how the soil N trans-formations associ...Water erosion process induces differences to the nitrogen(N)functional microbial community structure,which is the driving force to key N processes at soil-water interface.However,how the soil N trans-formations associated with water erosion is affected by microorganisms,and how the microbial respond,are still unclear.The objective of this study is to investigate the changes of microbial diversity and community structure of the N-cycle function microorganisms as affected by water erosion under application of organic manure and straw cover.On the basis of iso-nitrogen substitution,four treatments were set up:1)only chemical fertilizer with N 150 kg ha^(-1),P2O560 kg ha^(-1) and K2O 90 kg ha^(-1)(CK);the N was substituted 20%by 2)organic manure(OM);3)straw(SW);and 4)organic manure+straw(1:1)(OMSW).The results showed that applying organic manure and straw to sloping farmland can increase soil N contents,but reduce runoff depth,Kw,sediment yield and N loss,especially in the OMSW.Straw cover and straw+organic manure increased the diversity(Chao1)of nitrifier(AOB),and both diversity and uniformity(Shannon)of denitrifier(nirK/S)were increased in the OMSW.All erosion control mea-sures reduced N-fixing bacteria diversity and increased their uniformity,and the combined application of organic manure and straw cover was a better erosion control measure than the single application of them.Improved soil chemistry and erodibility were the main drives for the changes of N-functional microbial community structure and the appearance of dominant bacteria with different organic materials.展开更多
Loess water erosion constitutes a great threat to the safety of the West-to-East Gas Pipeline in China. Through aerial-photo interpretation and investigation of the typical region (Zichang (子长)-Yongping (水坪) ...Loess water erosion constitutes a great threat to the safety of the West-to-East Gas Pipeline in China. Through aerial-photo interpretation and investigation of the typical region (Zichang (子长)-Yongping (水坪) Section) where the loess water erosion problem is intensely developed, the influence of water erosion on the pipeline in the loess area can be manifested as the following 3 aspects: (1) surface and gully erosion causes the base overhead and pipeline exposure; (2) underground erosion forms caves, which may cause surface subsidence and foundation failure; (3) water erosion of loess may destroy the balance of slopes and cause geological hazards like landslide, collapse and debris flow. Presently, the controlling methods are mainly concrete or grouted rubble protection. These methods are not only high in cost but also have poor effect and poor durability. This article suggests a method of controlling the loess water erosion problem with soil solidified material. Then, related tests are conducted. The results of uniaxial compression, permeability, and anti-erosion ability tests indicate that the mechanical properties and anti-erosion ability of solidified loess were improved significantly.展开更多
Regionalization of soil and water conservation is a base for the planning of soil and water conservation in China. It can provide scientific basis for constructing healthy eco-environment and regional management and d...Regionalization of soil and water conservation is a base for the planning of soil and water conservation in China. It can provide scientific basis for constructing healthy eco-environment and regional management and development. It makes a brief review of related regionalization of study and makes clear the concept of regionalization of soil and water conservation. In this paper, based on synthetical analysis of the characteristics of eco-environments of China, the principles, indices and nomenclature of the regionalization of soil and water conservation are proposed. Through the construction of the regionalization of soil and water conservation collaboration platform and data reporting system, combined with existing soil and water conservation research, this paper uses the top-down and bottom-up and the combination of qualitative and quantitative methods to build soil and water conservation regionalization preliminary scheme, with 8 regions, 41 sub-regions and 117 sections divided in China.展开更多
基金jointly funded by the Sichuan Provincial Natural Science Foundation of China (Grant No.2023NSFSC0378)the Jiuzhaigou Lake Swamp and River Ecological Restoration Research Project (N5132112022000246)。
文摘A large number of loose piles formed by mountain hazards are highly susceptible to hydraulic erosion under rainfall conditions.The use of ecological substrate materials for erosion control and ecological restoration of gravel soil slopes has become a current research hotspot and the study difficulty.The post-earthquake slump accumulation gravel soil in Jiuzhaigou was selected as the research object,and the self-developed modified glutinous rice-based material was used to reinforce the gravel soil.The variable slope flume erosion test and rainfall simulation test were carried out to study the water erosion resistance of the material reconstructed soil under the influence of runoff erosion and raindrop splash erosion.The results show that:As the material content reached 12.5%,the reconstructed soil did not disintegrate after 24 hours of immersion,the internal friction angle was increased by 42.26%,and the cohesion was increased by 235.5%,which played a significant reinforcement effect.In the process of slope erosion,the soil rill erodibility parameter Kr was only 3‰ of the gravel soil control group,the critical shear force τ increased by 272%,and the soil erosion resistance was significantly improved.In the process of rainfall and rainfall on the slope,the runoff intensity of the reconstructed soil was stable,and the ability to resist runoff erosion and raindrop splash erosion was enhanced.The maximum value of soil loss rate on different slope slopes is 0.02-0.10 g·m^(-2)s^(-1),which is significantly lower than that of the control group and has better erosion reduction effect.
基金financially supported by the Special Program for Basic Research of the Ministry of Science and Technology, China (2014FY210100)the National Natural Science Foundation of China (41171422, 41271298)the West Light Foundation of the Chinese Academy of Sciences
文摘Wind and water erosion are among the most important causes of soil loss, and understanding their interactions is important for estimating soil quality and environmental impacts in regions where both types of erosion occur. We used a wind tunnel and simulated rainfall to study sediment yield, particle-size distribution and the fractal dimension of the sediment particles under wind and water erosion. The experiment was conducted with wind ero- sion firstly and water erosion thereafter, under three wind speeds (0, 11 and 14 m/s) and three rainfall intensities (60, 80 and 100 ram/h). The results showed that the sediment yield was positively correlated with wind speed and rain- fall intensity (P〈0.01). Wind erosion exacerbated water erosion and increased sediment yield by 7.25%-38.97% relative to the absence of wind erosion. Wind erosion changed the sediment particle distribution by influencing the micro-topography of the sloping land surface. The clay, silt and sand contents of eroded sediment were also posi- tively correlated with wind speed and rainfall intensity (P〈0.01). Wind erosion increased clay and silt contents by 0.35%-19.60% and 5.80%-21.10%, respectively, and decreased sand content by 2.40%-8.33%, relative to the absence of wind erosion. The effect of wind erosion on sediment particles became weaker with increasing rainfall intensities, which was consistent with the variation in sediment yield. However, particle-size distribution was not closely correlated with sediment yield (P〉0.05). The fractal dimension of the sediment particles was significantly different under different intensities of water erosion (P〈0.05), but no significant difference was found under wind and water erosion. The findings reported in this study implicated that both water and wind erosion should be controlled to reduce their intensifying effects, and the controlling of wind erosion could significantly reduce water erosion in this wind-water erosion crisscross region.
基金financially supported by the National Key Research and Development Program of China(Grant No.SQ2018YFD080041)the Sichuan Science and Technology Program(Grant No.2017SZ0188)。
文摘Soils in the hydro-fluctuation belts of the reservoirs are most highly influenced by the special hydro-conditions and reservoir operation,leading to unique soil erosion process and largely accelerate soil erosion intensity.The present study aimed to estimate soil erosion rate in the hydro-fluctuation belt of the Pubugou Reservoir,Southwest China,based on the framework of Universal Soil Loss Equation(USLE).An attempt has been made to modify the original USLE by including the reservoir water erosivity(W),a new factor into the model.Soil erosion rate from different land use types were quantitatively estimated,using the USLE and the modified USLE respectively.Field observation showed that soil erosion rate in dry farmland,bare land and grassland was 4700,44600 and 5050 t/km2,respectively.The erosion rate assessed by the modified USLE was closely related to that recorded from the field monitoring data.The findings of this study clearly highlight the importance of inclusion of the W factor to the original USLE model while assessing soil erosion in the reservoir hydro-fluctuation belt.
基金National Natural Science Foundation of China, No.30371191 The Ministry of Education of China, No.272008 Program for New Century Excellent Talents in University
文摘Complex erosion by wind and water, which is also called aeolian-fluvial interactions, is an important erosion process and landscape in arid and semiarid regions. The effectiveness of links between wind and water process, spatial environmental transitions and temporal environmental change are the three main driving forces determining the geomorphologic significance of aeolian-fluvial interactions. As a complex interrelating and intercoupling system, complex erosion by wind and water has spatial- temporal variation features. The process of complex erosion by wind and water can be divided into palaeoenvironmental process and contemporary process. Early work in drylands has often been attributed to one of two schools advocating either an 'aeolianist' or a 'fluvialist' perspective, so it was not until the 1930s that the research on complex erosion by wind and water had been conducted. There are two obstacles restricting the research of complex erosion by wind and water. Firstly, how to transform in different temporal and spatial scales is still unsettled; and secondly, the research methodology is still immature. In the future, the mechanism and control of erosion, the complex soil erodibility in wind and water erosion will be the focus of research on complex erosion by wind and water.
基金supported by the National Key Research and Development Program of China(2017YFC0505102)the National Natural Science Foundation of China(No.41401313)+2 种基金the Major Science and Technology Program for Water Pollution Control and Treatment(2017ZX07101001)the Applied Basic Research Program of Sichuan(2018JY0034)the Major Science and Technology Projects in Sichuan Province(2018SZDZX0034)。
文摘Both tillage erosion and water erosion are severe erosional forms that occur widely on sloping agricultural land.However,previous studies have rarely considered the process of landform change due to continuous simulation experiments of alternating tillage erosion and water erosion.To identify such changes,we applied a scouring experiment(at a 60 L min-1 water discharge rate based on precipitation data from the local meteorological station and the catchment area in the Yuanmou County,Yunnan Province,China)and a series of simulated tillage experiments where plots were consecutively tilled 5,10,and 15 times in rotation(representing 5 yr,10 yr,and 15 yr of tillage)at slope gradients of 5°,10°,and 20°.Close-range photogrammetry(CRP)employing an unmanned aerial vehicle(UAV)and a real-time kinematic global positioning system(RTK-GPS)was used to measure landform changes,and highresolution digital elevation models(DEMs)were generated to calculate net soil loss volumes.Additionally,the CRP was determined to be accurate and applicable through the use of erosion pins.The average tillage erosion rates were 69.85,131.45,and 155.34 t·hm-2·tillage pass-1,and the average water erosion rates were 1892.52,2961.76,and 4405.93 t·hm-2·h-1 for the 5°,10°,and 20°sloping farmland plots,respectively.The water erosion rates increased as tillage intensity increased,indicating that tillage erosion accelerates water erosion.Following these intensive tillage treatments,slope gradients gradually decreased,while the trend in slope gradients increased in runoff plots at the conclusion of the scouring experiment.Compared to the original plots(prior to our experiments),interactions between tillage and water erosion caused no obvious change in the landform structure of the runoff plots,while the height of all the runoff plots decreased.Our findings showed that both tillage erosion and water erosion caused a pseudo-steady-state landform evolutionary mechanism and resulted in thin soil layers on cultivated land composed of purple soil in China.
基金supported by the National Natural Science Foundation of China(41271286)the Innovative Research Group Project of the National Natural Science Foundation of China(413221001)
文摘In semi-arid regions, complex erosion resulted from a combination of wind and water actions has led to a massive soil loss and a comprehensive understanding of its mechanism is the first step toward prevention of the erosion. However, the mutual influences between wind erosion and water erosion have not been fully understood. This research used a wind tunnel and two rainfall simulators and simulated two rounds of alternations between wind erosion and water erosion(i.e., 1^(st) wind erosion–1^(st) water erosion and 2^(nd) wind erosion–2^(nd) water erosion) on three slopes(5°, 10°, and 15°) with six wind speeds(0, 9, 11, 13, 15, and 20 m/s) and five rainfall intensities(0, 30, 45, 60, and 75 mm/h). The objective was to analyze the influences of wind erosion on succeeding water erosion. Results showed that the effects of wind erosion on water erosion were not the same in the two rounds of tests. In the 1^(st) round of tests, wind erosion first restrained and then intensified water erosion mostly because the blocking effect of wind-sculpted micro-topography on surface flow was weakened with the increase in slope. In the 2^(nd) round of tests, wind erosion intensified water erosion on beds with no rills at gentle slopes and low rainfall intensities or with large-size rills at steep slopes and high rainfall intensities. Wind erosion restrained water erosion on beds with small rills at moderate slopes and moderate rainfall intensities. The effects were mainly related to the fine grain layer, rills and slope of the original bed in the 2^(nd) round of tests. The findings can deepen our understanding of complex erosion resulted from a combination of wind and water actions and provide scientific references to regional soil and water conservation.
基金supported by MC s.r.l.,by the university research project (University of Brescia) Health and Wealth 2015“URBAID (Rigenerazione urbana assistita e integrata)”by the call H2020-SwafS-2016-17 Science with and for Society (European project:“SciShops”: Enhancing the Responsible and Sustainable Expansion of the Science Shops Ecosystem in Europe)。
文摘To quantify water erosion rates and annual soil loss in mountainous areas,two different empirical models were used to estimate the effects of soil erosion in a small mountain basin,the Guerna Creek watershed,located in the Central Southern Alps(Northern Italy).These two models,Revised Universal Soil Loss Equation(RUSLE) and Erosion Potential Model(EPM),were implemented in a Geographical Information System,accounting for the geographical,geomorphological,and weather-climate parameters,which are fundamental to evaluating the intensity and variability of the erosive processes.Soil characterization was supported by laboratory analysis.The results(computed soil loss of 87 t/ha/year and 11.1 m^(3)/ha/year,using RUSLE equation and EPM method,respectively,and sediment yield of 7.5 m^(3)/ha/year using EPM method) were compared to other studies reported in the literature for different case studies with similar topographic and climatic features,as well as to those provided by the European Soil Data Centre(ESDAC).In both cases,the agreement was satisfactory,showing consistency of the adopted procedures to the parametrization of the physical processes.
文摘The watershed of the Arbaa Ayacha River is an environment favorable to the development of the phenomena of water erosion as a result of its topographic features, lithological and climate. Therefore it has been the subject of evaluation of states erosive and of different causal factors of the risk of erosion by adaptation of cross-matrices based on directives PAP/RAC (Priority Actions Programme/Regional Activity Centre) [1]. This method is based on three approaches. The predictive approach provides a synthetic map of the distribution of the erosive states, with 51% of the basin subjected to high risks. The descriptive mapping of the various forms of erosion shows an enormous extension of stripping and sheet erosion (91%), superficial gullies and moderately deep gullies are growing in view of the gathering of runoffs from upstream to the downstream. The superposition of the results of both predictive and descriptive approaches gives a consolidated map PAP/RAC whose analysis shows that soils’ loss throughout the basin is proportional to the increase of the major factors of water erosion according to the level of importance: The topographical factor—soil types—slope-lithology following a positive linear relationship, while the order of the parameters that are negative linear relationship is density of vegetation cover-land cover [2]. This same map gives maximal losses corresponding mainly to friable lithologic natural areas of badlands at the center of the basin which correspond to Tensift’s terraces [3]. In the downstream basin, the combined effect of deep ravines and banks sapements promotes high risk while in the upstream, the localized solifluxions and gravity screens participate in serious losses.
基金supported by the key research and development and transformation project of Qinghai Province,China(2022-SF-173)the Second Tibetan Plateau Scientific Expedition and Research Program,China(2019QZKK0606)the National Natural Science Foundation of China(42101027).
文摘Soil erosion is one of the most serious environmental issues constraining the sustainable development of human society and economies.Soil compound erosion is the result of the alternation or interaction between two or more erosion forces.In recent years,fluctuations and extreme changes in climatic factors(air temperature,precipitation,wind speed,etc.)have led to an increase in the intensity and extent of compound erosion,which is increasingly considered in soil erosion research.First,depending on the involvement of gravity,compound erosion process can be divided into compound erosion with and without gravity.We systematically summarized the research on the mechanisms and processes of alternating or interacting soil erosion forces(wind,water,and freeze-thaw)considering different combinations,combed the characteristics of compound erosion in three typical regions,namely,high-elevation areas,high-latitude areas,and dry and wet transition regions,and reviewed soil compound erosion research methods,such as station observations,simulation experiments,prediction models,and artificial neural networks.The soil erosion model of wind,water,and freeze-thaw interaction is the most significant method for quantifying and predicting compound erosion.Furthermore,it is proposed that there are several issues such as unclear internal mechanisms,lack of comprehensive prediction models,and insufficient scale conversion methods in soil compound erosion research.It is also suggested that future soil compound erosion mechanism research should prioritize the coupling of compound erosion forces and climate change.
基金supported by the National Natural Science Foundation of China (41271288, 41371273)
文摘As an important parameter in the soil erosion model, soil surface roughness(SSR) is used to quantitatively describe the micro-relief on agricultural land. SSR has been extensively studied both experimentally and theoretically; however, no studies have focused on understanding SSR on the Loess Plateau of China. This study investigated changes in SSR for three different tillage practices on the Loess Plateau of China and the effects of SSR on runoff and erosion yield during simulated rainfall. The tillage practices used were zero tillage(ZT), shallow hoeing(SH) and contour ploughing(CP). Two rainfall intensities were applied, and three stages of water erosion processes(splash erosion(I), sheet erosion(II) and rill erosion(III)) were analyzed for each rainfall intensity. The chain method was used to measure changes in SSR both initially and after each stage of rainfall. A splash board was used to measure the splash erosion at stage I. Runoff and sediment data were collected continuously at 2-min intervals during rainfall erosion stages II and III. We found that SSR of the tilled surfaces ranged from 1.0% to 21.9% under the three tillage practices, and the order of the initial SSR for the three treatments was ZT〈SH〈CP. For the ZT treatment, SSR increased slightly from stage I to III, whereas for the SH and CP treatments, SSR decreased by 44.5% and 61.5% after the three water erosion stages, respectively, and the greatest reduction in SSR occurred in stage I. Regression analysis showed that the changes in SSR with increasing cumulative rainfall could be described by a power function(R2〉0.49) for the ZT, SH and CP treatments. The runoff initiation time was longer in the SH and CP treatments than in the ZT treatment. There were no significant differences in the total runoff yields among the ZT, SH and CP treatments. Sediment loss was significantly smaller(P〈0.05) in the SH and CP treatments than in the ZT treatment.
基金the National Key R&D Program of China(Grant No.2017YFC0505603)the Special Fund for Basic Scientific Research of Central Colleges,China University of Geosciences,Wuhan.
文摘Climate,land use and land cover(LULC)changes are among the primary driving forces of soil loss.Decoupling their effects can help in understanding the magnitude and trend of soil loss in response to human activities and ecosystem management.Here,the RUSLE model was applied to estimate the spatial-temporal variations of soil loss rate in the Three Gorges Reservoir(TGR)area during 2001-2015,followed by a scenario design to decouple the effects of climate and LULC changes.The results showed that increasing rainfall generated as much as 2.90×10^(7)t soil loss in the TGR area.However,such effect was offset by changes in LULC particularly afforestation,which retained about 1.10×10^(7)t soil annually.Other human activities such as dam development and urbanization aggravated soil loss by as much as 1.40×10^(6)t annually.Because of land use policies that favor economic development,distinct spatial variances of soil loss were observed in TGR area.Soil loss in some counties located downstream of the TGR area(i.e.,close to the dam)was more influenced by dam development,but soil loss in the other counties was more influenced by urbanization.As climate change(i.e.,increasing rainfall)did not affect plant performance in TGR area,our findings suggested that ecological restoration was more beneficial to curb the amount of soil loss caused by urbanization and dam construction.
基金funded by the National Key Research and Development Program of China (2017YFC0504505)the National Key Technology Support Program of China during the Twelfth Five-year Plan Period (2013BAC05B02, 2013BAC05B04)
文摘The Pisha sandstone-coverd area is among the regions that suffer from the most severe water loss and soil erosion in China and is the main source of coarse sand for the Yellow River. This study demonstrated a new erosion control method using W-OH solution, a type of hydrophilic polyurethane, to prevent the Pisha sandstone from water erosion. We evaluated the comprehensive effects of W-OH on water erosion resistance and vegetation-growth promotion through simulated scouring tests and field demonstrations on the Ordos Plateau of China. The results of simulated scouring tests show that the water erosion resistance of W-OH treated area was excellent and the cumulative sediment yield reduction reached more than 99%. In the field demonstrations, the vegetation coverage reached approximately 95% in the consolidation-green area, and there was almost no shallow trenches on the entire slope in the treated area. In comparison, the control area experienced severe erosion with deep erosion gullies appeared on the slope and the vegetation coverage was less than 30%. This study illustrated that W-OH treatment can protect the Pisha sandstone from erosion and provide the vegetation seeds a chance to grow. Once the vegetation matured, the effects of consolidation-growth mutual promotion can efficiently and effectively improve the water erosion resistance and ecological restoration.
文摘Loess Plateau, an arid and semi arid region in Northwest China, is well known for its most serious soil erosion in terms of sediment yield each year. Soil erosion, which is intensified by agricultural activities, is the major factor influencing sustainable agriculture development in this region. It reduces productivity by removing nutrients and especially reducing water availability that is essential for crop production in the area. It also brings about off site costs by demanding more efforts for maintenance of banks and dams along Yellow River through raising the riverbed with sediment. Climate is capricious and extreme weather conditions occur frequently, which impairs normal agricultural production with erosion and also decrease of water availability. Extensive way of farming still dominates on the Loess Plateau, which cannot produce satisfying economic results and needs to be improved or altered. Conventional agricultural production pattern needs to be reconsidered for husbandry has not been granted its due position. Agriculture is the backbone of economy. Poor agricultural production impedes economic development and vice versa, backward economy also influences the advancement of agriculture. Besides a large population, education status of farmers is another threshold that requires being resolved for a sustainable agriculture. Although conventional agriculture has been practiced there for more than 5000 years, now it cannot meet the demand for food and fiber by the increasing population and some of its farming practices are contributing to environmental degradation directly or indirectly and can sustain no longer. Agriculture on Loess Plateau needs to find its own way of sustainability. To work toward a sustainable agriculture, chances and challenges both indwell on Loess Plateau.
文摘The soils of Benin in general and those of the department of Zou, in particular, are highly degraded. This study aimed to evaluate the effectiveness of sustainable land management practices on soil erodibility in two villages in the Plateau of Abomey. Soil samples were collected on plots under Sustainable Land Management (SLM) measures (direct seeding, maize residue management and soybean-cereal rotation) and on their adjacent control. The soil samples were prepared and analyzed in laboratory to determine variables such as soil permeability, organic matter content, and particle size. Soil erodibility was determined as proposed by Wischmeier & Smith. The effect of SLM practices was significant (0.02) on soil permeability. On plots under SLM measurements, soil permeability is higher with an average of 93.97 mm/h at Folly and 82.43 mm/h at Hanagbo. SLM measurements significantly (0.04) added organic matter to the soil. The average organic matter of the plots under SLM measures in Folly varies from 0.73% to 1.39% while it varies from 0.49% to 0.73% in the control plots. In Hanagbo, the average organic matter of the plots under SLM measures varies from 1.86% to 2.48% against 1.41% to 1.66% for the control plots. Regarding soil erodibility, it was found that the influence of SLM measures is significant in both villages. In villages, direct seeding and maize residue management significantly (0.008) reduced soil erodibility compared to their adjacent controls, while the soybean-cereal rotation measure increased soil erodibility compared to plot witnesses. The average soil erodibility of plots under SLM measures varies by 0.21 t⋅h/Mj⋅mm at 0.38 t⋅h/Mj⋅mm in the village of Hanagbo and 0.25 t⋅h/Mj⋅mm at 0.38 t⋅h/Mj⋅mm in the village of Folly. It varies from 0.24 t⋅h/Mj⋅mm at 0.28 t⋅h/Mj⋅mm for the control plots at Hanagbo and 0.31 t⋅h/Mj⋅mm at 0.37 t⋅h/Mj⋅mm in Folly. These practices can therefore be used for the sustainable use of agricultural land.
基金supported by The National Natural Science Foundation of China (Grant No. 40861013)Natural Science Foundation of Inner Mongolia (Grant No. 200508010708)
基金supported by the National Natural Science Foundation of China(Grant No.U19A2047)the Natural Science Foundation of Hunan Province(Grant No.2023JJ20030)。
文摘To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and quantified.It is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(2)at the basin scale,which encompasses the entire hydrological process.This study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin scale.Applying this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1980-2020 was 1.33×10^(8)t,displaying a decreasing trend followed by a slight increase.Only 12% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the basin.The average lateral soil organic carbon loss induced by erosion was 8.86×10^(11)g C in 1980 and 1.50×10^(11)g C in 2020,with a decline rate of 83%.A net land sink for atmospheric CO_(2)of 5.54×1011g C a^(-1)occurred during erosion,primarily through sediment burial and dynamic replacement.However,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon removal.Moreover,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long timeframes.Consequently,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.
基金supported by the National Science and Technology Support Plan(No.2014BAC15B03)the Recruitment Program of High Level Talents in Xinjiang,and the Young Talents Cultivation Program for Science and Technology Innovation in Xinjiang(No.2014731010).
文摘Located in the inland arid area of Central Asia and northwest China,Xinjiang has recently received heightened concerns over soil water erosion,which is highly related with the sustainable utilization of barren soil and limited water resources.Data from the national soil erosion survey of China(1985-2011)and Xinjiang statistical yearbook(2000-2010)was used to analyze the trend,intensity,and serious soil water erosion regions.Results showed that the water erosion area in Xinjiang was 87.6103 km^(2) in 2011,mainly distributed in the Ili river valley and the northern and southern Tian Mountain.Soil erosion gradient was generally slight and the average erosion modulus was 2184 t/(km^(2) a).During the last 26 years,the water erosion area in Xinjiang decreased by 23.2%,whereas the intensity was still increasing.The driving factors from large to small impact included:population boom and human activities4vegetation degradation4rainfall and climate change4topography and soil erodibility4tectonics movement.Soil water erosion resulted in eco-environmental and socioeconomic losses,such as destroying farmland and grassland,triggering floods,sedimentation of reservoirs,damaging transportation and irrigation facilities,and aggravating poverty.A landscape ecological design approach is suggested for integrated control of soil erosion.Currently,an average of 2.07×10^(3) km^(2) of formerly eroded area is conserved each year.This study highlighted the importance and longevity of soil and water conservation efforts in Xinjiang,and offered some suggestions on ecological restoration and combating desertification in arid regions of Central Asia.&2015 International Research and Training Center on Erosion and Sedimentation and China Water and Power Press.Production and Hosting by Elsevier B.V.This is an open access article under the CC BY-NC-ND license(http://creativecommons.org/licenses/by-nc-nd/4.0/).
基金Financial support for this study was provided by the National Nature Science Foundation of China(No.41977072)the Special Fund for Agro-scientific Research in the Public Interest(201503119)the Agricultural Science and Technology Innovation Program(ASTIP).
文摘Water erosion process induces differences to the nitrogen(N)functional microbial community structure,which is the driving force to key N processes at soil-water interface.However,how the soil N trans-formations associated with water erosion is affected by microorganisms,and how the microbial respond,are still unclear.The objective of this study is to investigate the changes of microbial diversity and community structure of the N-cycle function microorganisms as affected by water erosion under application of organic manure and straw cover.On the basis of iso-nitrogen substitution,four treatments were set up:1)only chemical fertilizer with N 150 kg ha^(-1),P2O560 kg ha^(-1) and K2O 90 kg ha^(-1)(CK);the N was substituted 20%by 2)organic manure(OM);3)straw(SW);and 4)organic manure+straw(1:1)(OMSW).The results showed that applying organic manure and straw to sloping farmland can increase soil N contents,but reduce runoff depth,Kw,sediment yield and N loss,especially in the OMSW.Straw cover and straw+organic manure increased the diversity(Chao1)of nitrifier(AOB),and both diversity and uniformity(Shannon)of denitrifier(nirK/S)were increased in the OMSW.All erosion control mea-sures reduced N-fixing bacteria diversity and increased their uniformity,and the combined application of organic manure and straw cover was a better erosion control measure than the single application of them.Improved soil chemistry and erodibility were the main drives for the changes of N-functional microbial community structure and the appearance of dominant bacteria with different organic materials.
基金supported by the National Natural Science Foundation of China (No. 40972185)
文摘Loess water erosion constitutes a great threat to the safety of the West-to-East Gas Pipeline in China. Through aerial-photo interpretation and investigation of the typical region (Zichang (子长)-Yongping (水坪) Section) where the loess water erosion problem is intensely developed, the influence of water erosion on the pipeline in the loess area can be manifested as the following 3 aspects: (1) surface and gully erosion causes the base overhead and pipeline exposure; (2) underground erosion forms caves, which may cause surface subsidence and foundation failure; (3) water erosion of loess may destroy the balance of slopes and cause geological hazards like landslide, collapse and debris flow. Presently, the controlling methods are mainly concrete or grouted rubble protection. These methods are not only high in cost but also have poor effect and poor durability. This article suggests a method of controlling the loess water erosion problem with soil solidified material. Then, related tests are conducted. The results of uniaxial compression, permeability, and anti-erosion ability tests indicate that the mechanical properties and anti-erosion ability of solidified loess were improved significantly.
基金National Forestry Public Welfare Industry Research of China,No.201004018Project of the Ministry of Water Resources
文摘Regionalization of soil and water conservation is a base for the planning of soil and water conservation in China. It can provide scientific basis for constructing healthy eco-environment and regional management and development. It makes a brief review of related regionalization of study and makes clear the concept of regionalization of soil and water conservation. In this paper, based on synthetical analysis of the characteristics of eco-environments of China, the principles, indices and nomenclature of the regionalization of soil and water conservation are proposed. Through the construction of the regionalization of soil and water conservation collaboration platform and data reporting system, combined with existing soil and water conservation research, this paper uses the top-down and bottom-up and the combination of qualitative and quantitative methods to build soil and water conservation regionalization preliminary scheme, with 8 regions, 41 sub-regions and 117 sections divided in China.