The Experts below are selected from a list of 131337 Experts worldwide ranked by ideXlab platform
Yu Liu - One of the best experts on this subject based on the ideXlab platform.
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A sedimentological connectivity approach for assessing on-site and off-site Soil Erosion control services
Ecological Indicators, 2020Co-Authors: Yu Liu, Liang ZhaoAbstract:Abstract Soil Erosion, a widely-occurring phenomenon in the terrestrial environment, affects land productivity and infrastructure security negatively both on-site and off-site. Therefore, Soil Erosion control services (SECS) are one of the most fundamental ecosystem services for human well-being. Although previous SECS assessments elaborated the benefits from preventing on-site Soil Erosion and Soil loss comprehensively, the off-site benefits remain vague. They are usually estimated only through multiplying the capacity of on-site Soil Erosion prevention by land-use-based, and spatially consistent, allocation coefficients. The corresponding overestimation, item omission, and inability to represent the spatial heterogeneity of SECS may lead to great uncertainties. In addition, the SECS decay with travel distance is not well represented, because of a neglect of the cascading nature of SECS formation and its delivery. Here, to address these deficiencies, a cascade framework for SECS assessment is developed that incorporates the concept of sedimentological connectivity over the landscape. This approach quantifies both the on-site Soil Erosion prevention and mitigation of sediment delivery over the landscape, based on an understanding of the cascading nature of Soil Erosion and sediment delivery, by referring to the framework of WATEM/SEDEM that potentially reveals the sedimentological connectivity over landscape. A monetized valuation of SECS delivered to local communities was derived by employing a land-use based replacement cost technique, which takes cultivated land units as a SECS receiver and conveyer. The approach was applied in a loess catchment located in the middle Yellow River basin, China as a case study. For this watershed, with an area of 54.2 km2, the gross Soil Erosion reduction was up to 156.93 × 104 t; the reduction of sediment input was 11.28 × 104 t; and the reduction in gross sediment export is up to 181.34 × 104 t. The monetized SECS value delivered to utilized land units was 910.13 × 104 CNY. The approach described provides a tool that specifically addresses the SECSs directly useful to humans, contributes to quantifying the Soil Erosion control services provided by the landscape, and improves the reliability of SECS evaluation.
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hydrological responses and Soil Erosion potential of abandoned cropland in the loess plateau china
Geomorphology, 2012Co-Authors: Yu Liu, Zhi Wang, Guangyao GaoAbstract:Recent changes in hydrological processes and Soil Erosion in the Loess Plateau, China, are immediate responses to cropland abandonment for revegetation, which lead to a long-term decrease in runoff generation and Soil Erosion. However, detailed hydrological responses and Soil Erosion changes have not been clearly evaluated. In this study, two issues were focused on the plot scale. The first issue relates to changes in vegetation cover and Soil properties during the early stages of revegetation. Given the occurrence of Soil compaction, it was hypothesized that runoff increased during this period and the Soil Erosion did not significantly decline, even though vegetation increased. The second issue is the effect of scale on runoff and Soil Erosion. Three plot groups of three vegetation types and two restoration stages were established for comparative experiments. The results from these experiments confirmed that the Soil compaction occurred during revegetation in this region. Greater runoff was produced in plot group that experienced both a longer restoration time and with higher vegetation cover (such as Groups 2 and 3 in this study) than that with a shorter restoration time and lower vegetation cover (Group 1). In addition, the total Soil loss rates of all plot groups were rather low and did not significantly differ from each other. This indicates that a reduction in runoff generation and Soil Erosion, as a result of revegetation, was limited in the early stages of restoration following the cropland abandonment. With increasing plot area, the runoff coefficient decreased for the plot group with a longer revegetation time (Groups 2 and 3), but gently increased for the one with a shorter restoration time (Group 1). In Groups 2 and 3, Soil loss rate decreased when plot area enlarged. In Group 1, it decreased before a plot area threshold of 18 m(2) was exceeded. However, the increase occurred when plot area crossed the threshold value. In conclusion, the high vegetation cover alone did not lead to reduction in the runoff coefficient during the early stages of revegetation. When evaluating hydrological and Soil Erosion responses to revegetation, the Soil compaction processes should be considered. Additionally, the effect of scale on runoff and Soil Erosion was found to be dependent on restoration extent, and thus on restoration time. (C) 2011 Elsevier BY. All rights reserved.
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assessing the Soil Erosion control service of ecosystems change in the loess plateau of china
Ecological Complexity, 2011Co-Authors: Yu Liu, Yua ZengAbstract:Abstract Soil Erosion in terrestrial ecosystems, as an important global environmental problem, significantly impacts on environmental quality and social economy. By protecting Soil from wind and water Erosion, terrestrial ecosystems supply human beings with Soil Erosion control service, one of the fundamental ecosystem services that ensure human welfare. The Loess Plateau was one of the regions in the world that suffered from severe Soil Erosion. In the past decades, restoration projects were implemented to improve Soil Erosion control in the region. The Grain-to-Green project, converting slope croplands into forest or grasslands, launched in 1999 was the most massive one. It is needed to assess the change of Soil Erosion control service brought about by the project. This study evaluated the land cover changes from 2000 to 2008 by satellite image interpretation. Universal Soil Loss Equation (USLE) was employed for the Soil Erosion control assessment for the same period with localized parameters. Soil retention calculated as potential Soil Erosion (Erosion without vegetation cover) minus actual Soil Erosion was applied as indicator for Soil Erosion control service. The results indicate that ecosystem Soil Erosion control service has been improved from 2000 to 2008 as a result of vegetation restoration. Average Soil retention rate (the ratio of Soil retention to potential Soil loss in percentage) was up to 63.3% during 2000–2008. Soil loss rate in 34% of the entire plateau decreased, 48% unchanged and 18% slightly increased. Areas suffering from intense Erosion shrank and light Erosion areas expanded. Zones with slope gradient of 8°–35° were the main contribution area of Soil loss. On average, these zones produced 82% of the total Soil loss with 45.5% of the total area in the Loess Plateau. Correspondingly, Soil Erosion control capacity was significantly improved in these zones. Soil loss rate decreased from 5000 t km −2 yr −1 to 3600 t km −2 yr −1 , 6900 t km −2 yr −1 to 4700 t km −2 yr −1 , and 8500 t km −2 yr −1 to 5500 t km −2 yr −1 in the zones with slope gradient of 8°–15°, 15°–25°, and 25°–35° respectively. However, the mean Soil Erosion rate in areas with slope gradient over 8° was still larger than 3600 t km −2 yr −1 , which is far beyond the tolerable Erosion rate of 1000 t km −2 yr −1 . Thus, Soil Erosion is still one of the top environmental problems that need more ecological restoration efforts.
Lin Zhen - One of the best experts on this subject based on the ideXlab platform.
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Soil Erosion control practices in the Chinese Loess Plateau: A systematic review
Environmental Development, 2020Co-Authors: Xin Wen, Lin ZhenAbstract:Abstract Soil Erosion control practices have been extensively conducted in the Chinese Loess Plateau, which is one of the most severe Soil Erosion regions in the world. Nevertheless, a comprehensive overview of the effectiveness of these Erosion control practices in this region is lacking. Thus, this systematic review examined the use of Erosion control practices in the Chinese Loess Plateau. The key question addressed in this paper is: how Soil Erosion control practices have been used in the Chinese Loess Plateau? The assessment was based on (1) the categories of Erosion control practice, (2) the spatial scales conducted by each Erosion control practice, and (3) the cost-effectiveness of each Erosion control practice. One hundred peer-reviewed papers were selected, and our results highlighted: (1) 57% of the studies, 32% of the studies, and 11% of the studies evaluated the effectiveness or impacts of ecological restoration programs, engineering techniques, and Soil management techniques on Soil Erosion, respectively, but multiple Erosion control practices evaluation received a little attention. (2) The watershed scale assessment dominated the published studies (65% of the reviewed papers), followed by plot scale assessments (35% of the reviewed papers), but the cross-scale evaluation has received little attention. (3) Soil Erosion control practices have enhanced most of the Soil-related ecosystem services but partially damaged water-related ecosystem services. These control practices caused trade-offs between Soil Erosion control and water provision and synergies between Soil Erosion control and water use efficiency, water regulation, and crop production. These synergy and trade-off relationships among Soil Erosion control practices and ecosystem services might be changed as time passes. Then, three recommendations are suggested for future studies: (1) a combination of Erosion control practice assessment needs to be developed, (2) a cross-scale assessment needs to be examined, and (3) a rational balance between Soil and water conservation needs to be considered.
Peng Gao - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Soil Erosion models used to study the Chinese Loess Plateau
Earth-Science Reviews, 2017Co-Authors: Joseph Holden, Guangju Zhao, Fei Wang, Peng Gao, Brian Irvine, Wenyi SunAbstract:Abstract The Loess Plateau suffers from severe Soil Erosion that leads to a series of ecological and economic problems such as reduced land productivity, exacerbated rural poverty, decreased biodiversity and sedimentation of the riverbed in the lower reaches of the Yellow River. Soil Erosion models are commonly used on the Loess Plateau to help target sustainable land management strategies to control Soil Erosion. In this study, we compared eleven Soil Erosion models that were previously used on the Loess Plateau. We studied their prediction accuracy, process representation, data and calibration requirements, and potential application in scenario studies. The selected models consisted of a broad range of model types, structures and scales. The comparison showed that process-based and empirical models did not necessarily yield more accurate results over one another for the Loess Plateau. Among the process-based models, Si’ model, WEPP and MMF had the highest prediction accuracy. However, some of the selected models were tested with total sediment load while others were tested with suspended sediment load (i.e. bedload is not included), which is subject to several drawbacks. Research questions that each of the models can address on the Loess Plateau were suggested. Further improvement of Soil Erosion models for the Loess Plateau should concentrate on enhancing the quality of data for model implementation and testing, incorporating key processes into process-based models according to their aims and scales, comparing models that address the same research questions, and implementing internal and spatial model testing.
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Soil Erosion conservation and eco environment changes in the loess plateau of china
Land Degradation & Development, 2013Co-Authors: Guangju Zhao, Fei Wang, Peng GaoAbstract:As one of the best-known areas in the world, the Loess Plateau, has long been suffering from serious Soil Erosion. The present paper reviewed the historical variation of climate, vegetation cover, and environment changes in order to understand the causes of severe Soil Erosion. Documentary evidence indicated that climate changes and vegetation cover were the dominant natural factors influencing the Soil Erosion rates during the Holocene. Intensive human activities consisting of warfare, population growth, deforestation, and Soil and water conservation measures were responsible for the changes of Soil Erosion during the anthropogenic period. Spatial and temporal changes of specific sediment yields presented significant decrease within the last several decades, which resulted from decreasing rainfall, large scale Soil and water conservation measures, agricultural irrigation, and reservoir construction. Different phase of Soil conservation measures demonstrated the development of policies and techniques on Soil Erosion control. Effective strategies of Soil and water conservation, consisting of terracing, afforestation, natural rehabilitation, and check-dams construction, were carried out on the Loess Plateau during the past six decades. The progress of Soil conservation measures confirmed that the check-dams systems might be suitable for Loess hilly Plateau, and natural vegetation rehabilitation is the best way for Soil Erosion control and should be implemented in other regions with emphasis of improving the quality of conservation measures based on natural rehabilitation. Copyright © 2013 John Wiley & Sons, Ltd.
Guangju Zhao - One of the best experts on this subject based on the ideXlab platform.
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Comparison of Soil Erosion models used to study the Chinese Loess Plateau
Earth-Science Reviews, 2017Co-Authors: Joseph Holden, Guangju Zhao, Fei Wang, Peng Gao, Brian Irvine, Wenyi SunAbstract:Abstract The Loess Plateau suffers from severe Soil Erosion that leads to a series of ecological and economic problems such as reduced land productivity, exacerbated rural poverty, decreased biodiversity and sedimentation of the riverbed in the lower reaches of the Yellow River. Soil Erosion models are commonly used on the Loess Plateau to help target sustainable land management strategies to control Soil Erosion. In this study, we compared eleven Soil Erosion models that were previously used on the Loess Plateau. We studied their prediction accuracy, process representation, data and calibration requirements, and potential application in scenario studies. The selected models consisted of a broad range of model types, structures and scales. The comparison showed that process-based and empirical models did not necessarily yield more accurate results over one another for the Loess Plateau. Among the process-based models, Si’ model, WEPP and MMF had the highest prediction accuracy. However, some of the selected models were tested with total sediment load while others were tested with suspended sediment load (i.e. bedload is not included), which is subject to several drawbacks. Research questions that each of the models can address on the Loess Plateau were suggested. Further improvement of Soil Erosion models for the Loess Plateau should concentrate on enhancing the quality of data for model implementation and testing, incorporating key processes into process-based models according to their aims and scales, comparing models that address the same research questions, and implementing internal and spatial model testing.
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Soil Erosion conservation and eco environment changes in the loess plateau of china
Land Degradation & Development, 2013Co-Authors: Guangju Zhao, Fei Wang, Peng GaoAbstract:As one of the best-known areas in the world, the Loess Plateau, has long been suffering from serious Soil Erosion. The present paper reviewed the historical variation of climate, vegetation cover, and environment changes in order to understand the causes of severe Soil Erosion. Documentary evidence indicated that climate changes and vegetation cover were the dominant natural factors influencing the Soil Erosion rates during the Holocene. Intensive human activities consisting of warfare, population growth, deforestation, and Soil and water conservation measures were responsible for the changes of Soil Erosion during the anthropogenic period. Spatial and temporal changes of specific sediment yields presented significant decrease within the last several decades, which resulted from decreasing rainfall, large scale Soil and water conservation measures, agricultural irrigation, and reservoir construction. Different phase of Soil conservation measures demonstrated the development of policies and techniques on Soil Erosion control. Effective strategies of Soil and water conservation, consisting of terracing, afforestation, natural rehabilitation, and check-dams construction, were carried out on the Loess Plateau during the past six decades. The progress of Soil conservation measures confirmed that the check-dams systems might be suitable for Loess hilly Plateau, and natural vegetation rehabilitation is the best way for Soil Erosion control and should be implemented in other regions with emphasis of improving the quality of conservation measures based on natural rehabilitation. Copyright © 2013 John Wiley & Sons, Ltd.
Xin Wen - One of the best experts on this subject based on the ideXlab platform.
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Soil Erosion control practices in the Chinese Loess Plateau: A systematic review
Environmental Development, 2020Co-Authors: Xin Wen, Lin ZhenAbstract:Abstract Soil Erosion control practices have been extensively conducted in the Chinese Loess Plateau, which is one of the most severe Soil Erosion regions in the world. Nevertheless, a comprehensive overview of the effectiveness of these Erosion control practices in this region is lacking. Thus, this systematic review examined the use of Erosion control practices in the Chinese Loess Plateau. The key question addressed in this paper is: how Soil Erosion control practices have been used in the Chinese Loess Plateau? The assessment was based on (1) the categories of Erosion control practice, (2) the spatial scales conducted by each Erosion control practice, and (3) the cost-effectiveness of each Erosion control practice. One hundred peer-reviewed papers were selected, and our results highlighted: (1) 57% of the studies, 32% of the studies, and 11% of the studies evaluated the effectiveness or impacts of ecological restoration programs, engineering techniques, and Soil management techniques on Soil Erosion, respectively, but multiple Erosion control practices evaluation received a little attention. (2) The watershed scale assessment dominated the published studies (65% of the reviewed papers), followed by plot scale assessments (35% of the reviewed papers), but the cross-scale evaluation has received little attention. (3) Soil Erosion control practices have enhanced most of the Soil-related ecosystem services but partially damaged water-related ecosystem services. These control practices caused trade-offs between Soil Erosion control and water provision and synergies between Soil Erosion control and water use efficiency, water regulation, and crop production. These synergy and trade-off relationships among Soil Erosion control practices and ecosystem services might be changed as time passes. Then, three recommendations are suggested for future studies: (1) a combination of Erosion control practice assessment needs to be developed, (2) a cross-scale assessment needs to be examined, and (3) a rational balance between Soil and water conservation needs to be considered.
