Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake
Abstract Background Strong earthquakes are among the prime triggering factors of landslides, which may block rivers, forming landslide dams. Some of these dams may pose serious threats to people and property due to upstream inundation and downstream dam-breach flooding. Evaluating the stability and...
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| Format: | Article |
| Language: | English |
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SpringerOpen
2017-04-01
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| Series: | Geoenvironmental Disasters |
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| Online Access: | http://link.springer.com/article/10.1186/s40677-017-0079-8 |
| _version_ | 1818910402428272640 |
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| author | Xuanmei Fan Qiang Xu Cees J. van Westen Runqiu Huang Ran Tang |
| author_facet | Xuanmei Fan Qiang Xu Cees J. van Westen Runqiu Huang Ran Tang |
| author_sort | Xuanmei Fan |
| collection | DOAJ |
| description | Abstract Background Strong earthquakes are among the prime triggering factors of landslides, which may block rivers, forming landslide dams. Some of these dams may pose serious threats to people and property due to upstream inundation and downstream dam-breach flooding. Evaluating the stability and potential hazard of landslide dams is significant for the mitigation measures, but remains challenging. The 2008 Wenchuan earthquake (M w 7.9) in China triggered numerous landslides over a broad area, some of which dammed rivers, posing severe threats to downstream settlements. Our previous study created one of the most complete landslide dam inventories including detailed geomorphic parameters of 828 landslide dams induced by the Wenchuan earthquake. This paper presents the study of a number of representative landslide dams associated with the 2008 Wenchuan earthquake. Results The coseismic landslides were classified into rock/debris avalanches, debris flows, rock/debris slides and rock falls. According to dam composition material and sedimentological features, landslide dams were categorized into three types: dams mainly composed of large boulders and blocks; dams composed of unconsolidated fine debris; and dams with partly intact rock strata at the base topped by large boulders and blocks or soil with rock fragments, showing two-layered or three-layered depositional structure. This classification is linked to the typology of damming landslides and considered to be a preliminary indicator of dam stability. In addition, dam stability also largely depends on valley morphometry as well as landslide runout distance and mechanism. The post-earthquake debris flow damming events induced by subsequent rainfalls are also introduced. It was found that there is still a large amount of loose sediment remaining on the slope, which may continue promoting heavy debris flows and dams in the coming years or decades. Conclusions The classification of landslide dams proposed in this study can be used as a preliminary indicator of dam stability. More reliable assessment requires a geotechnical approach taking into account a variety of dynamic loading scenarios, and also relies on knowledge about the accurate dam and barrier-lake geometry. There is still a large amount of loose sediment remaining on the slopes, which may be reactivated and remobilized during the heavy post-earthquake rainstorms. Therefore, predicting the post-earthquake debris flows and evaluating their potential for damming rivers are still of great concern and remain as a main challenge. |
| first_indexed | 2024-12-19T22:42:14Z |
| format | Article |
| id | doaj.art-e626827aaa134b15a689eb64ce59ba4d |
| institution | Directory Open Access Journal |
| issn | 2197-8670 |
| language | English |
| last_indexed | 2024-12-19T22:42:14Z |
| publishDate | 2017-04-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Geoenvironmental Disasters |
| spelling | doaj.art-e626827aaa134b15a689eb64ce59ba4d2022-12-21T20:03:02ZengSpringerOpenGeoenvironmental Disasters2197-86702017-04-014111510.1186/s40677-017-0079-8Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquakeXuanmei Fan0Qiang Xu1Cees J. van Westen2Runqiu Huang3Ran Tang4The State Key Laboratory of Geohazards Prevention and Geoenvironment Protection, Chengdu University of TechnologyThe State Key Laboratory of Geohazards Prevention and Geoenvironment Protection, Chengdu University of TechnologyFaculty of Geo-Information Science and Earth Observation (ITC), University of TwenteThe State Key Laboratory of Geohazards Prevention and Geoenvironment Protection, Chengdu University of TechnologyThe State Key Laboratory of Geohazards Prevention and Geoenvironment Protection, Chengdu University of TechnologyAbstract Background Strong earthquakes are among the prime triggering factors of landslides, which may block rivers, forming landslide dams. Some of these dams may pose serious threats to people and property due to upstream inundation and downstream dam-breach flooding. Evaluating the stability and potential hazard of landslide dams is significant for the mitigation measures, but remains challenging. The 2008 Wenchuan earthquake (M w 7.9) in China triggered numerous landslides over a broad area, some of which dammed rivers, posing severe threats to downstream settlements. Our previous study created one of the most complete landslide dam inventories including detailed geomorphic parameters of 828 landslide dams induced by the Wenchuan earthquake. This paper presents the study of a number of representative landslide dams associated with the 2008 Wenchuan earthquake. Results The coseismic landslides were classified into rock/debris avalanches, debris flows, rock/debris slides and rock falls. According to dam composition material and sedimentological features, landslide dams were categorized into three types: dams mainly composed of large boulders and blocks; dams composed of unconsolidated fine debris; and dams with partly intact rock strata at the base topped by large boulders and blocks or soil with rock fragments, showing two-layered or three-layered depositional structure. This classification is linked to the typology of damming landslides and considered to be a preliminary indicator of dam stability. In addition, dam stability also largely depends on valley morphometry as well as landslide runout distance and mechanism. The post-earthquake debris flow damming events induced by subsequent rainfalls are also introduced. It was found that there is still a large amount of loose sediment remaining on the slope, which may continue promoting heavy debris flows and dams in the coming years or decades. Conclusions The classification of landslide dams proposed in this study can be used as a preliminary indicator of dam stability. More reliable assessment requires a geotechnical approach taking into account a variety of dynamic loading scenarios, and also relies on knowledge about the accurate dam and barrier-lake geometry. There is still a large amount of loose sediment remaining on the slopes, which may be reactivated and remobilized during the heavy post-earthquake rainstorms. Therefore, predicting the post-earthquake debris flows and evaluating their potential for damming rivers are still of great concern and remain as a main challenge.http://link.springer.com/article/10.1186/s40677-017-0079-8LandslideLandslide damWenchuan earthquakeStabilityClassification |
| spellingShingle | Xuanmei Fan Qiang Xu Cees J. van Westen Runqiu Huang Ran Tang Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake Geoenvironmental Disasters Landslide Landslide dam Wenchuan earthquake Stability Classification |
| title | Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake |
| title_full | Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake |
| title_fullStr | Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake |
| title_full_unstemmed | Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake |
| title_short | Characteristics and classification of landslide dams associated with the 2008 Wenchuan earthquake |
| title_sort | characteristics and classification of landslide dams associated with the 2008 wenchuan earthquake |
| topic | Landslide Landslide dam Wenchuan earthquake Stability Classification |
| url | http://link.springer.com/article/10.1186/s40677-017-0079-8 |
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