In order to understand the process of surface erosion and acquire basic data of conditions on hillslope without vegetation, a sprinkling experiment is conducted on a bare slope in Mt.Tanakami in the central part of Ja...In order to understand the process of surface erosion and acquire basic data of conditions on hillslope without vegetation, a sprinkling experiment is conducted on a bare slope in Mt.Tanakami in the central part of Japan. Based on the measurements of runoff, mean soil erosion depth, and sediment yield, etc., the results suggest the following characteristics in the process of surface erosion in the experimental area. (1) The occurrence of sediment discharge is interrupted; (2) Surface runoff is a saturated overland flow; (3) The mean soil erosion depth is thick compared with other areas in Mt.Tanakami; (4) Sediment discharge process is detachment-limited.展开更多
The existing^(210)Pb_(ex)mass balance models for the assessment of cultivated soil erosion are based on an assumption that^(210)Pb_(ex)is quite evenly mixed within the plough layer.However,the amount of^(210)Pb_(ex)di...The existing^(210)Pb_(ex)mass balance models for the assessment of cultivated soil erosion are based on an assumption that^(210)Pb_(ex)is quite evenly mixed within the plough layer.However,the amount of^(210)Pb_(ex)distributed in the soils below the plough depth,like a downward tail in the lower part of the^(210)Pb_(ex)profile,has been largely ignored.In fact,after the initial cultivation of undisturbed soils,^(210)Pb_(ex)will diffuse downward from plough layer to the plough pan layer due to the concentration gradient.Assuming^(210)Pb_(ex)inventory is constant,the depth distribution in the two layers of the cultivated soils will achieve a steady state after continuous cultivation for 10.37 years,when^(210)Pb_(ex)is evenly distributed in the soils of the plough layer with an exponential concentration decline with depth in the soils of the plough pan layer,and the^(210)Pb_(ex)concentration at any depth will be invariable with time.The work reported in this paper attempts to explain the formation of the^(210)Pb_(ex)tail in the soil profile below the plough depth by theoretical derivation of the^(210)Pb_(ex)depth distribution process in the two layers of the cultivated soils,propose a^(210)Pb_(ex)mass balance model considering^(210)Pb_(ex)diffusion based on the existing model,and discuss the influence of the^(210)Pb_(ex)tail to the existing model.展开更多
The study area is one of the areas in the South-South region of Nigeria that has been ravaged by erosion.This has led to loss of infrastructures and impact on the livelihood of the inhabitants of the study area.In thi...The study area is one of the areas in the South-South region of Nigeria that has been ravaged by erosion.This has led to loss of infrastructures and impact on the livelihood of the inhabitants of the study area.In this study,the physio-chemical of soil in Agbor and its neighboring communities were assessed in eleven different locations.A total of eleven soil samples,consisting of 5 samples each at a depth of 0–200 cm were taken in accordance with the clarification of different horizons.The samples were air-dried,crushed and sieved in 2mm mesh sieve then subjected to analysis for both physical and chemical properties in the laboratory.The physiochemical analysis results showed that pH value ranges from 5.0 to 6.3 indicating very strongly acidic to strongly acidic.Bulk density ranged from 1.29 to1.35 indicating a slight increase due to the presence of sand fraction.And low level of porosity which ranged from 49.4 to 50.9.The low level obtained from Total Organic Matter(TOM)indicates intense rainfall and constant leaching.The low Ca,Mg,K+and Na+values indicate intense rainfall and leaching problems.The values obtained from Al3+,H+,EA and P revealed a slight increase and cause of acidity nature across eleven soil test sites.The properties showed by all soils revealed that they are vulnerable to weathering,leaching,easy removal by runoff and low resistivity.展开更多
In order to understand the process of surface erosion and its changing characteristics, a sprinkling experiment is conducted on a bare slope in Mt. Tanakami. Based on the measurements and analysis of runoff, mean soil...In order to understand the process of surface erosion and its changing characteristics, a sprinkling experiment is conducted on a bare slope in Mt. Tanakami. Based on the measurements and analysis of runoff, mean soil erosion depth sediment yield and semiment transport, etc., the characteristics in the process of surface erosion in the experimental area are as follows: the occurrence of sediment discharge is interrupted, with a saturated overland-flow surface runoff; the mean erosion depth is 0.086 2 cm, which is thicker compared with other areas in Mt. Tanakmi; sediment yield is 431. 283 m3·km?2, whose process is detachment-limited, and the type of sediment transport is a sediment flow. Key words runoff - soil erosion depth - sediment yield - sediment transport - Mt. Tanakami CLC number S 157 Biography: ZHAO Wei (1975-), female, Ph. D candidate, Lecturer, now is working in College of Earth Sciences, Jilin University, research dircetion: physical geography, environmental planning and management展开更多
Labile organic carbon(LOC)is a fraction of soil organic carbon(SOC)with rapid turnover time and is affected by soil fertilization.This investigation characterized the SOC content,LOC content and LOC distribution in th...Labile organic carbon(LOC)is a fraction of soil organic carbon(SOC)with rapid turnover time and is affected by soil fertilization.This investigation characterized the SOC content,LOC content and LOC distribution in the treatment plots of surface soil erosion at five levels(0-,5-,10-,20-and 30-cm erosion).The soil had received contrasting fertilizer treatments(i.e.,chemical fertilizer or chemical fertilizer+manure)for 6 years.This study demonstrated that both SOC and various LOC fractions contents were higher in the plots with fertilizer+manure than in those with fertilizer alone under the same erosion conditions.The SOC and LOC contents decreased as the erosion depth increased.Light fraction organic carbon,particulate organic carbon,easily oxidizable organic carbon(KMnO4-oxydizable organic carbon),and microbial biomass carbon were 27%–57%,37%–47%,20%–25%,and 29%–33%higher respectively in the fertilizer+manure plots,than in the fertilizer alone plots.Positive correlations(p<0.05)between SOC content and different fractions contents were observed in all plots except the correlation between total SOC content and water-soluble organic carbon content in the different fertilization treatments.Obviously,fertilizer+manure treatments would be conducive to the accumulation of LOC and SOC in the Black soil of Northeast China.展开更多
The study of wind erosion processes is of great importance to the prevention and control of soil wind erosion.In this study,three structurally intact soil samples were collected from the steppe of Inner Mongolia Auton...The study of wind erosion processes is of great importance to the prevention and control of soil wind erosion.In this study,three structurally intact soil samples were collected from the steppe of Inner Mongolia Autonomous Region,China and placed in a wind tunnel where they were subjected to six different wind speeds(10,15,17,20,25,and 30 m/s)to simulate wind erosion in the wind tunnel.After each test,the soil surfaces were scanned by a 3D laser scanner to create a high-resolution Digital Elevation Model(DEM),and the changes in wind erosion mass and microtopography were quantified.Based on this,we performed further analysis of wind erosion-controlling factors.The study results showed that the average measurement error between the 3D laser scanning method and weighing method was 6.23%for the three undisturbed soil samples.With increasing wind speed,the microtopography on the undisturbed soil surface first became smooth,and then fine stripes and pits gradually developed.In the initial stage of wind erosion processes,the ability of the soil to resist wind erosion was mainly affected by the soil hardness.In the late stage of wind erosion processes,the degree of soil erosion was mainly affected by soil organic matter and CaCO_(3)content.The results of this study are expected to provide a theoretical basis for soil wind erosion control and promote the application of 3D laser scanners in wind erosion monitoring.展开更多
The negative effect of soil erosion and soil compaction is well documented for the purpose of optimum rangeland functioning, while the impact of rangeland degradation on effective soil depth is seldom quantified. The ...The negative effect of soil erosion and soil compaction is well documented for the purpose of optimum rangeland functioning, while the impact of rangeland degradation on effective soil depth is seldom quantified. The aim of this study was to quantify the response of vegetation cover and soil properties, particularly effective soil depth and soil texture to rangeland degradation. Forty-one farms were sampled in the arid and semi-arid climate of South Africa. Within these farms, data was collected over a vegetation degradation gradient. Results showed a significant decline in relative basal cover (94% ± 15% to 39% ± 17%) and soil depth (90% ± 14% to 73% ± 24%) as rangeland degraded. Soil texture changes over the degradation gradients vary for different homogeneous vegetation types. Indications regarding the loss of a functioning rangeland ecosystem were also demonstrated, using objective long-term relations between rangeland conditions and grazing capacity. The study highlights the importance of sustainable rangeland management practices to reduce the loss in effective soil depth and to ensure the sustainable utilization of the rangeland ecosystem. These results can probably extrapolate to other arid and semi-arid rangelands worldwide.展开更多
文摘In order to understand the process of surface erosion and acquire basic data of conditions on hillslope without vegetation, a sprinkling experiment is conducted on a bare slope in Mt.Tanakami in the central part of Japan. Based on the measurements of runoff, mean soil erosion depth, and sediment yield, etc., the results suggest the following characteristics in the process of surface erosion in the experimental area. (1) The occurrence of sediment discharge is interrupted; (2) Surface runoff is a saturated overland flow; (3) The mean soil erosion depth is thick compared with other areas in Mt.Tanakami; (4) Sediment discharge process is detachment-limited.
基金Supported by National Natural Science Foundation of China(Nos.41102224 and 41101259)
文摘The existing^(210)Pb_(ex)mass balance models for the assessment of cultivated soil erosion are based on an assumption that^(210)Pb_(ex)is quite evenly mixed within the plough layer.However,the amount of^(210)Pb_(ex)distributed in the soils below the plough depth,like a downward tail in the lower part of the^(210)Pb_(ex)profile,has been largely ignored.In fact,after the initial cultivation of undisturbed soils,^(210)Pb_(ex)will diffuse downward from plough layer to the plough pan layer due to the concentration gradient.Assuming^(210)Pb_(ex)inventory is constant,the depth distribution in the two layers of the cultivated soils will achieve a steady state after continuous cultivation for 10.37 years,when^(210)Pb_(ex)is evenly distributed in the soils of the plough layer with an exponential concentration decline with depth in the soils of the plough pan layer,and the^(210)Pb_(ex)concentration at any depth will be invariable with time.The work reported in this paper attempts to explain the formation of the^(210)Pb_(ex)tail in the soil profile below the plough depth by theoretical derivation of the^(210)Pb_(ex)depth distribution process in the two layers of the cultivated soils,propose a^(210)Pb_(ex)mass balance model considering^(210)Pb_(ex)diffusion based on the existing model,and discuss the influence of the^(210)Pb_(ex)tail to the existing model.
文摘The study area is one of the areas in the South-South region of Nigeria that has been ravaged by erosion.This has led to loss of infrastructures and impact on the livelihood of the inhabitants of the study area.In this study,the physio-chemical of soil in Agbor and its neighboring communities were assessed in eleven different locations.A total of eleven soil samples,consisting of 5 samples each at a depth of 0–200 cm were taken in accordance with the clarification of different horizons.The samples were air-dried,crushed and sieved in 2mm mesh sieve then subjected to analysis for both physical and chemical properties in the laboratory.The physiochemical analysis results showed that pH value ranges from 5.0 to 6.3 indicating very strongly acidic to strongly acidic.Bulk density ranged from 1.29 to1.35 indicating a slight increase due to the presence of sand fraction.And low level of porosity which ranged from 49.4 to 50.9.The low level obtained from Total Organic Matter(TOM)indicates intense rainfall and constant leaching.The low Ca,Mg,K+and Na+values indicate intense rainfall and leaching problems.The values obtained from Al3+,H+,EA and P revealed a slight increase and cause of acidity nature across eleven soil test sites.The properties showed by all soils revealed that they are vulnerable to weathering,leaching,easy removal by runoff and low resistivity.
文摘In order to understand the process of surface erosion and its changing characteristics, a sprinkling experiment is conducted on a bare slope in Mt. Tanakami. Based on the measurements and analysis of runoff, mean soil erosion depth sediment yield and semiment transport, etc., the characteristics in the process of surface erosion in the experimental area are as follows: the occurrence of sediment discharge is interrupted, with a saturated overland-flow surface runoff; the mean erosion depth is 0.086 2 cm, which is thicker compared with other areas in Mt. Tanakmi; sediment yield is 431. 283 m3·km?2, whose process is detachment-limited, and the type of sediment transport is a sediment flow. Key words runoff - soil erosion depth - sediment yield - sediment transport - Mt. Tanakami CLC number S 157 Biography: ZHAO Wei (1975-), female, Ph. D candidate, Lecturer, now is working in College of Earth Sciences, Jilin University, research dircetion: physical geography, environmental planning and management
基金Under the auspices of National Natural Science Foundation of China(No.41271313,41172229,41071171)Harbin Bureau of Science and Technology for Outstanding Scientist(No.2010FXYN044)
文摘Labile organic carbon(LOC)is a fraction of soil organic carbon(SOC)with rapid turnover time and is affected by soil fertilization.This investigation characterized the SOC content,LOC content and LOC distribution in the treatment plots of surface soil erosion at five levels(0-,5-,10-,20-and 30-cm erosion).The soil had received contrasting fertilizer treatments(i.e.,chemical fertilizer or chemical fertilizer+manure)for 6 years.This study demonstrated that both SOC and various LOC fractions contents were higher in the plots with fertilizer+manure than in those with fertilizer alone under the same erosion conditions.The SOC and LOC contents decreased as the erosion depth increased.Light fraction organic carbon,particulate organic carbon,easily oxidizable organic carbon(KMnO4-oxydizable organic carbon),and microbial biomass carbon were 27%–57%,37%–47%,20%–25%,and 29%–33%higher respectively in the fertilizer+manure plots,than in the fertilizer alone plots.Positive correlations(p<0.05)between SOC content and different fractions contents were observed in all plots except the correlation between total SOC content and water-soluble organic carbon content in the different fertilization treatments.Obviously,fertilizer+manure treatments would be conducive to the accumulation of LOC and SOC in the Black soil of Northeast China.
基金supported by National Natural Science Foundation of China(41871010)The Second Comprehensive Scientific Expedition to the Qinghai-Tibet Plateau of China(2019QZKK0906)。
文摘The study of wind erosion processes is of great importance to the prevention and control of soil wind erosion.In this study,three structurally intact soil samples were collected from the steppe of Inner Mongolia Autonomous Region,China and placed in a wind tunnel where they were subjected to six different wind speeds(10,15,17,20,25,and 30 m/s)to simulate wind erosion in the wind tunnel.After each test,the soil surfaces were scanned by a 3D laser scanner to create a high-resolution Digital Elevation Model(DEM),and the changes in wind erosion mass and microtopography were quantified.Based on this,we performed further analysis of wind erosion-controlling factors.The study results showed that the average measurement error between the 3D laser scanning method and weighing method was 6.23%for the three undisturbed soil samples.With increasing wind speed,the microtopography on the undisturbed soil surface first became smooth,and then fine stripes and pits gradually developed.In the initial stage of wind erosion processes,the ability of the soil to resist wind erosion was mainly affected by the soil hardness.In the late stage of wind erosion processes,the degree of soil erosion was mainly affected by soil organic matter and CaCO_(3)content.The results of this study are expected to provide a theoretical basis for soil wind erosion control and promote the application of 3D laser scanners in wind erosion monitoring.
文摘The negative effect of soil erosion and soil compaction is well documented for the purpose of optimum rangeland functioning, while the impact of rangeland degradation on effective soil depth is seldom quantified. The aim of this study was to quantify the response of vegetation cover and soil properties, particularly effective soil depth and soil texture to rangeland degradation. Forty-one farms were sampled in the arid and semi-arid climate of South Africa. Within these farms, data was collected over a vegetation degradation gradient. Results showed a significant decline in relative basal cover (94% ± 15% to 39% ± 17%) and soil depth (90% ± 14% to 73% ± 24%) as rangeland degraded. Soil texture changes over the degradation gradients vary for different homogeneous vegetation types. Indications regarding the loss of a functioning rangeland ecosystem were also demonstrated, using objective long-term relations between rangeland conditions and grazing capacity. The study highlights the importance of sustainable rangeland management practices to reduce the loss in effective soil depth and to ensure the sustainable utilization of the rangeland ecosystem. These results can probably extrapolate to other arid and semi-arid rangelands worldwide.
