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Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake
Changes in river channel erosion or deposition affect the geomorphic evolution, aquatic ecosystems, and river regulation strategies. Fluvial processes are determined by the flow, sediment and boundary conditions, and it has long been expected that increasing sediment supply will induce aggradation....
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5114544/ https://www.ncbi.nlm.nih.gov/pubmed/27857220 http://dx.doi.org/10.1038/srep37108 |
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author | Fan, Niannian Nie, Ruihua Wang, Qiang Liu, Xingnian |
author_facet | Fan, Niannian Nie, Ruihua Wang, Qiang Liu, Xingnian |
author_sort | Fan, Niannian |
collection | PubMed |
description | Changes in river channel erosion or deposition affect the geomorphic evolution, aquatic ecosystems, and river regulation strategies. Fluvial processes are determined by the flow, sediment and boundary conditions, and it has long been expected that increasing sediment supply will induce aggradation. Here, based on thorough field surveys, we show the unexpected undercutting of the piedmont rivers influenced by the 2008 Wenchuan (Ms 8.0) Earthquake. The rivers flow from the Longmen Mountain with significant topographic relief to the flat Chengdu plain. In the upstreams, sediment supply increased because of the landslides triggered by the earthquake, causing deposition in the upstream mountain reaches. However, the downstream plain reaches suffered undercutting instead of deposition, and among those rivers, Shiting River was the most seriously affected, with the largest undercutting depth exceeding 20 m. The reasons for this unexpected undercutting are proposed herein and relate to both natural and anthropogenic causes. In addition, we also demonstrate, at least for certain conditions, such as rivers flowing from large-gradient mountain regions to low-gradient plain regions, that upstream sediment pulses may induce aggradation in upstream and degradation in downstream, causing the longitudinal profile to steepen to accommodate the increasing sediment flux. |
format | Online Article Text |
id | pubmed-5114544 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-51145442016-11-25 Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake Fan, Niannian Nie, Ruihua Wang, Qiang Liu, Xingnian Sci Rep Article Changes in river channel erosion or deposition affect the geomorphic evolution, aquatic ecosystems, and river regulation strategies. Fluvial processes are determined by the flow, sediment and boundary conditions, and it has long been expected that increasing sediment supply will induce aggradation. Here, based on thorough field surveys, we show the unexpected undercutting of the piedmont rivers influenced by the 2008 Wenchuan (Ms 8.0) Earthquake. The rivers flow from the Longmen Mountain with significant topographic relief to the flat Chengdu plain. In the upstreams, sediment supply increased because of the landslides triggered by the earthquake, causing deposition in the upstream mountain reaches. However, the downstream plain reaches suffered undercutting instead of deposition, and among those rivers, Shiting River was the most seriously affected, with the largest undercutting depth exceeding 20 m. The reasons for this unexpected undercutting are proposed herein and relate to both natural and anthropogenic causes. In addition, we also demonstrate, at least for certain conditions, such as rivers flowing from large-gradient mountain regions to low-gradient plain regions, that upstream sediment pulses may induce aggradation in upstream and degradation in downstream, causing the longitudinal profile to steepen to accommodate the increasing sediment flux. Nature Publishing Group 2016-11-18 /pmc/articles/PMC5114544/ /pubmed/27857220 http://dx.doi.org/10.1038/srep37108 Text en Copyright © 2016, The Author(s) http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Article Fan, Niannian Nie, Ruihua Wang, Qiang Liu, Xingnian Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake |
title | Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake |
title_full | Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake |
title_fullStr | Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake |
title_full_unstemmed | Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake |
title_short | Dramatic undercutting of piedmont rivers after the 2008 Wenchuan Ms 8.0 Earthquake |
title_sort | dramatic undercutting of piedmont rivers after the 2008 wenchuan ms 8.0 earthquake |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5114544/ https://www.ncbi.nlm.nih.gov/pubmed/27857220 http://dx.doi.org/10.1038/srep37108 |
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