Uncertainty propagation in aeolian processes: From threshold shear velocity to sand transport rate.
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| Title: | Uncertainty propagation in aeolian processes: From threshold shear velocity to sand transport rate. |
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| Authors: | Raffaele, Lorenzo1,2 lorenzo.raffaele@polito.it, Bruno, Luca1,2, Wiggs, Giles F.S.2,3 |
| Source: | Geomorphology. Jan2018, Vol. 301, p28-38. 11p. |
| Subjects: | Wind erosion, Atmospheric transport, Sand dunes, Shear (Mechanics), Theory of wave motion |
| Abstract: | The accurate estimation of aeolian saltation events is a fundamental requirement in the modelling of wind erosion, dust emission, dune movement and aeolian hazard prediction. A large number of semi-empirical sand transport rate models exist, with many relying on a single value for a shear velocity threshold above which saltation is initiated. However, measuring and modelling the sand transport rate suffers from the effects of a number of epistemic and aleatory uncertainties which make the identification of a single threshold value for shear velocity problematic. This paper focuses on the uncertainty propagation evident in calculations that use a threshold shear velocity to estimate sand transport rate. Probability density functions of threshold shear velocity are provided from the authors' previous studies. Grain diameter and shear velocity are considered as deterministically varying parameters. Several sand transport rate statistical metrics are estimated via the Monte Carlo approach adopting four different sand transport models. The sand transport rate estimation in probabilistic terms allows us to assess the amplification/reduction in the uncertainty and to provide a deeper insight into established transport rate models. We find that if the wind speed is close to the erosion threshold, every tested model amplifies the variability of the resulting estimated sand transport rate, especially in the case of coarse sand. If the wind speed is large, the adopted models present substantial differences in uncertainty. An interpretation of these differences is given by conditioning the sand transport rate models to the type of erosion threshold adopted, the fluid or impact threshold. [ABSTRACT FROM AUTHOR] |
| Copyright of Geomorphology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 126478796 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Uncertainty propagation in aeolian processes: From threshold shear velocity to sand transport rate. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Raffaele%2C+Lorenzo%22">Raffaele, Lorenzo</searchLink><relatesTo>1,2</relatesTo><i> lorenzo.raffaele@polito.it</i><br /><searchLink fieldCode="AR" term="%22Bruno%2C+Luca%22">Bruno, Luca</searchLink><relatesTo>1,2</relatesTo><br /><searchLink fieldCode="AR" term="%22Wiggs%2C+Giles+F%2ES%2E%22">Wiggs, Giles F.S.</searchLink><relatesTo>2,3</relatesTo> – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Geomorphology%22">Geomorphology</searchLink>. Jan2018, Vol. 301, p28-38. 11p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Wind+erosion%22">Wind erosion</searchLink><br /><searchLink fieldCode="DE" term="%22Atmospheric+transport%22">Atmospheric transport</searchLink><br /><searchLink fieldCode="DE" term="%22Sand+dunes%22">Sand dunes</searchLink><br /><searchLink fieldCode="DE" term="%22Shear+%28Mechanics%29%22">Shear (Mechanics)</searchLink><br /><searchLink fieldCode="DE" term="%22Theory+of+wave+motion%22">Theory of wave motion</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: The accurate estimation of aeolian saltation events is a fundamental requirement in the modelling of wind erosion, dust emission, dune movement and aeolian hazard prediction. A large number of semi-empirical sand transport rate models exist, with many relying on a single value for a shear velocity threshold above which saltation is initiated. However, measuring and modelling the sand transport rate suffers from the effects of a number of epistemic and aleatory uncertainties which make the identification of a single threshold value for shear velocity problematic. This paper focuses on the uncertainty propagation evident in calculations that use a threshold shear velocity to estimate sand transport rate. Probability density functions of threshold shear velocity are provided from the authors' previous studies. Grain diameter and shear velocity are considered as deterministically varying parameters. Several sand transport rate statistical metrics are estimated via the Monte Carlo approach adopting four different sand transport models. The sand transport rate estimation in probabilistic terms allows us to assess the amplification/reduction in the uncertainty and to provide a deeper insight into established transport rate models. We find that if the wind speed is close to the erosion threshold, every tested model amplifies the variability of the resulting estimated sand transport rate, especially in the case of coarse sand. If the wind speed is large, the adopted models present substantial differences in uncertainty. An interpretation of these differences is given by conditioning the sand transport rate models to the type of erosion threshold adopted, the fluid or impact threshold. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of Geomorphology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.geomorph.2017.10.028 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 11 StartPage: 28 Subjects: – SubjectFull: Wind erosion Type: general – SubjectFull: Atmospheric transport Type: general – SubjectFull: Sand dunes Type: general – SubjectFull: Shear (Mechanics) Type: general – SubjectFull: Theory of wave motion Type: general Titles: – TitleFull: Uncertainty propagation in aeolian processes: From threshold shear velocity to sand transport rate. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Raffaele, Lorenzo – PersonEntity: Name: NameFull: Bruno, Luca – PersonEntity: Name: NameFull: Wiggs, Giles F.S. IsPartOfRelationships: – BibEntity: Dates: – D: 15 M: 01 Text: Jan2018 Type: published Y: 2018 Identifiers: – Type: issn-print Value: 0169555X Numbering: – Type: volume Value: 301 Titles: – TitleFull: Geomorphology Type: main |
| ResultId | 1 |
