The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow River.Since the 1950s,progressive soil and water conservation measur...The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow River.Since the 1950s,progressive soil and water conservation measures have been implemented—in particular,large-scale ecological restoration has been ongoing since 1999—resulting in a significant reduction of the sediment load.However,the mechanism of the sediment transport dynamics is not fully understood due to multiple and complicated influencing factors including climate change and human activities(e.g.,ecological restoration).A challenging question,then,arises:Is the current low sediment level a“new normal”in this era and in the future?To address this question,we selected a typical loess hilly region where considerable ecological restoration has been implemented,and which is regarded as the site of the first and most representative Grainfor-Green program in the Loess Plateau.We investigated the evolution of discharge–sediment relationships in the past decades(1960–2010)and their association with the soil and water conservation measures in this area.The results showed that there was a distinct change in the regression parameters of the commonly used annual discharge–sediment regression equation—a continuously increasing trend of parameter b and a decreasing trend of parameter a,accompanying the ecological restoration.The increase in exponent b(i.e.,a steeper slope)implies a potential lower sediment load resulting from low discharge and a potential higher sediment load resulting from large discharge.This finding may question the new normal of a low sediment level and implies the potential risk of a large sediment load during extremely wet years.展开更多
In a river, sediment discharge, which goes through erosion, transport, and deposition by flowing water, is important data for river projects. The transport of river sediment occurs depending on the conveyance of a cha...In a river, sediment discharge, which goes through erosion, transport, and deposition by flowing water, is important data for river projects. The transport of river sediment occurs depending on the conveyance of a channel as the basin sediment discharge, which has been introduced to the river via the outflow of the basin by the erosion of fertile topsoil or ground surface due to rainfall in the target basin, and the sediment eroded within the channel is mixed together. River sediment is a major factor for river formation and ecological habitat, and is a field that is difficult to analyze or predict. For the abandoned channel restoration of the Mangyeong River, this study aimed to develop a discharge-suspended sediment load rating curve by collecting suspended load and bed material at the Bong-dong gauging station, which is a test section. The developed discharge-suspended sediment load rating curve was proposed based on the existing discharge data and the measured sediment load. The measured data and the rating curve will be used as the major data for stability and habitat restoration during channel restoration.展开更多
基金funded by the Shaanxi Key Research and Development Program of China(2018ZDXM-GY-030)the National Thousand Youth Talent Program of China,the Hundred Youth Talent Program of Shaanxi Province,the Fundamental Research Funds for the Central Universities(xjj2018204)+3 种基金the Young Talent Support Plan of Xi’an Jiaotong University,the National Natural Science Foundation of China(31741020)the Postdoctoral Science Foundation of China(2016M592777)We are grateful to the editors and the reviewers for their constructive comments and suggestions to improve this paperWe also thank the HPCC Platform in Xi’an Jiaotong University for computing equipment and computer maintenance.
文摘The Chinese Loess Plateau is the most seriously eroded area in the world and contributes the vast majority of the sediment that goes into the Yellow River.Since the 1950s,progressive soil and water conservation measures have been implemented—in particular,large-scale ecological restoration has been ongoing since 1999—resulting in a significant reduction of the sediment load.However,the mechanism of the sediment transport dynamics is not fully understood due to multiple and complicated influencing factors including climate change and human activities(e.g.,ecological restoration).A challenging question,then,arises:Is the current low sediment level a“new normal”in this era and in the future?To address this question,we selected a typical loess hilly region where considerable ecological restoration has been implemented,and which is regarded as the site of the first and most representative Grainfor-Green program in the Loess Plateau.We investigated the evolution of discharge–sediment relationships in the past decades(1960–2010)and their association with the soil and water conservation measures in this area.The results showed that there was a distinct change in the regression parameters of the commonly used annual discharge–sediment regression equation—a continuously increasing trend of parameter b and a decreasing trend of parameter a,accompanying the ecological restoration.The increase in exponent b(i.e.,a steeper slope)implies a potential lower sediment load resulting from low discharge and a potential higher sediment load resulting from large discharge.This finding may question the new normal of a low sediment level and implies the potential risk of a large sediment load during extremely wet years.
文摘In a river, sediment discharge, which goes through erosion, transport, and deposition by flowing water, is important data for river projects. The transport of river sediment occurs depending on the conveyance of a channel as the basin sediment discharge, which has been introduced to the river via the outflow of the basin by the erosion of fertile topsoil or ground surface due to rainfall in the target basin, and the sediment eroded within the channel is mixed together. River sediment is a major factor for river formation and ecological habitat, and is a field that is difficult to analyze or predict. For the abandoned channel restoration of the Mangyeong River, this study aimed to develop a discharge-suspended sediment load rating curve by collecting suspended load and bed material at the Bong-dong gauging station, which is a test section. The developed discharge-suspended sediment load rating curve was proposed based on the existing discharge data and the measured sediment load. The measured data and the rating curve will be used as the major data for stability and habitat restoration during channel restoration.
