Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast Range
Although accurate root cohesion model estimates are essential to quantify the effect of vegetation roots on shallow slope stability, few means exist to independently validate such model outputs. One validation approach for cohesion estimates is back-calculation of apparent root cohesion at a landsli...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-09-01
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| Series: | GeoHazards |
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| Online Access: | https://www.mdpi.com/2624-795X/3/3/22 |
| _version_ | 1797487917800620032 |
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| author | Collin Cronkite-Ratcliff Kevin M. Schmidt Charlotte Wirion |
| author_facet | Collin Cronkite-Ratcliff Kevin M. Schmidt Charlotte Wirion |
| author_sort | Collin Cronkite-Ratcliff |
| collection | DOAJ |
| description | Although accurate root cohesion model estimates are essential to quantify the effect of vegetation roots on shallow slope stability, few means exist to independently validate such model outputs. One validation approach for cohesion estimates is back-calculation of apparent root cohesion at a landslide site with well-documented failure conditions. The catchment named CB1, near Coos Bay, Oregon, USA, which experienced a shallow landslide in 1996, is a prime locality for cohesion model validation, as an abundance of data and observations from the site generated broad insights related to hillslope hydrology and slope stability. However, previously published root cohesion values at CB1 used the Wu and Waldron model (WWM), which assumes simultaneous root failure and therefore likely overestimates root cohesion. Reassessing published cohesion estimates from this site is warranted, as more recently developed models include the fiber bundle model (FBM), which simulates progressive failure with load redistribution, and the root bundle model-Weibull (RBMw), which accounts for differential strain loading. We applied the WWM, FBM, and RBMw at CB1 using post-failure root data from five vegetation species. At CB1, the FBM and RBMw predict values that are less than 30% of the WWM-estimated values. All three models show that root cohesion has substantial spatial heterogeneity. Most parts of the landslide scarp have little root cohesion, with areas of high cohesion concentrated near plant roots. These findings underscore the importance of using physically realistic models and considering lateral and vertical spatial heterogeneity of root cohesion in shallow landslide initiation and provide a necessary step towards independently assessing root cohesion model validity. |
| first_indexed | 2024-03-09T23:55:37Z |
| format | Article |
| id | doaj.art-8ef83a672b1e4f14a7245785be7a4b77 |
| institution | Directory Open Access Journal |
| issn | 2624-795X |
| language | English |
| last_indexed | 2024-03-09T23:55:37Z |
| publishDate | 2022-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | GeoHazards |
| spelling | doaj.art-8ef83a672b1e4f14a7245785be7a4b772023-11-23T16:26:27ZengMDPI AGGeoHazards2624-795X2022-09-013342845110.3390/geohazards3030022Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast RangeCollin Cronkite-Ratcliff0Kevin M. Schmidt1Charlotte Wirion2U.S. Geological Survey, Moffett Field, CA 94035, USAU.S. Geological Survey, Moffett Field, CA 94035, USAETH Zurich, 8092 Zürich, SwitzerlandAlthough accurate root cohesion model estimates are essential to quantify the effect of vegetation roots on shallow slope stability, few means exist to independently validate such model outputs. One validation approach for cohesion estimates is back-calculation of apparent root cohesion at a landslide site with well-documented failure conditions. The catchment named CB1, near Coos Bay, Oregon, USA, which experienced a shallow landslide in 1996, is a prime locality for cohesion model validation, as an abundance of data and observations from the site generated broad insights related to hillslope hydrology and slope stability. However, previously published root cohesion values at CB1 used the Wu and Waldron model (WWM), which assumes simultaneous root failure and therefore likely overestimates root cohesion. Reassessing published cohesion estimates from this site is warranted, as more recently developed models include the fiber bundle model (FBM), which simulates progressive failure with load redistribution, and the root bundle model-Weibull (RBMw), which accounts for differential strain loading. We applied the WWM, FBM, and RBMw at CB1 using post-failure root data from five vegetation species. At CB1, the FBM and RBMw predict values that are less than 30% of the WWM-estimated values. All three models show that root cohesion has substantial spatial heterogeneity. Most parts of the landslide scarp have little root cohesion, with areas of high cohesion concentrated near plant roots. These findings underscore the importance of using physically realistic models and considering lateral and vertical spatial heterogeneity of root cohesion in shallow landslide initiation and provide a necessary step towards independently assessing root cohesion model validity.https://www.mdpi.com/2624-795X/3/3/22root reinforcementshallow landslidesslope stability |
| spellingShingle | Collin Cronkite-Ratcliff Kevin M. Schmidt Charlotte Wirion Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast Range GeoHazards root reinforcement shallow landslides slope stability |
| title | Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast Range |
| title_full | Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast Range |
| title_fullStr | Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast Range |
| title_full_unstemmed | Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast Range |
| title_short | Comparing Root Cohesion Estimates from Three Models at a Shallow Landslide in the Oregon Coast Range |
| title_sort | comparing root cohesion estimates from three models at a shallow landslide in the oregon coast range |
| topic | root reinforcement shallow landslides slope stability |
| url | https://www.mdpi.com/2624-795X/3/3/22 |
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