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dc.contributor.authorSHARPE, RICHARD
dc.contributor.authorBROOKS, ANDREW
dc.contributor.authorOLLEY, JON
dc.contributor.authorHUGHES, LAWRENCE
dc.contributor.authorKEMP, JUSTINE
dc.date.accessioned2021-03-03T01:52:34Z
dc.date.available2021-03-03T01:52:34Z
dc.date.issued2019
dc.identifier.doi10.3850/38wc092019-1649
dc.identifier.urihttp://hdl.handle.net/10072/402749
dc.description.abstractA substantial body of literature exists on the influence of vegetation on flow resistance in rivers and floodplains. Research has shown that the quadratic drag force-velocity relationship used in boundary layer theory does not hold when flexible vegetation bends under the influence of drag. As such, a small number of drag force models that aim to account for reconfiguration of tree foliage have been developed. Drag force measurements for testing and parameterizing thesemodels are limited, especially for Australian riparian tree species. This paper presents work that is being undertaken to measure drag forces on Casuarina cunninghamiana (river she oak). The research aims to measure drag forces across a range of tree sizes and velocities to test published drag force models, and ultimately, to model flow resistance through monocultural stands of C. cunninghamiana. Initial experiments were undertaken on an estuary. A drag resistance frame was designed and constructed and attached to the side of a boat to measure drag forces. Since drag on rigid smooth cylinders is well established, initial experiments used rigid cylinders to test the experiment design. The results replicate expected drag coefficients for velocities greater than 1.0 m/s. At lower velocities, drag coefficients were high and substantial noise was encountered due to lateral vibration of the frame. This suggests that the drag resistance frame requires adaption to overcome vibrations that may have been amplified by resonance. Methods for estimating tree area and flexural rigidity are also presented. Near field LiDAR survey and photographic survey were used to estimate the frontal area of a sample tree. The relationship between pulling force and tree deflection for an in-situ tree was also recorded. The results suggest that, for the velocities tested in the drag experiments, drag forces on the sample tree would cause substantial bending of the tree stems. It is expected that the reconfigured tree frontal area will influence the drag force-velocity relationship, which will be investigated in future experiments measuring drag forces on trees.
dc.description.peerreviewedYes
dc.publisherThe International Association for Hydro-Environment Engineering and Research (IAHR)
dc.relation.ispartofconferencename38th IAHR World Congress
dc.relation.ispartofconferencetitleProceedings of the 38th IAHR World Congress (Panama)
dc.relation.ispartofdatefrom2019-01-01
dc.relation.ispartofdateto2019-01-06
dc.relation.ispartoflocationPanama City, Panama
dc.relation.ispartofpagefrom5537
dc.relation.ispartofpageto5545
dc.subject.fieldofresearchEcological applications
dc.subject.fieldofresearchPhysical oceanography
dc.subject.fieldofresearchcode4102
dc.subject.fieldofresearchcode370803
dc.titleMeasuring Drag Forces on Casuarina Cunninghamiana in Experimental and Field Settings
dc.typeConference output
dc.type.descriptionE1 - Conferences
dcterms.bibliographicCitationSHARPE, R; BROOKS, A; OLLEY, JON; HUGHES, L; KEMP, J, Measuring Drag Forces on Casuarina Cunninghamiana in Experimental and Field Settings, Proceedings of the 38th IAHR World Congress (Panama), 2019
dc.date.updated2021-03-03T01:30:48Z
gro.hasfulltextNo Full Text
gro.griffith.authorKemp, Justine
gro.griffith.authorBrooks, Andrew P.


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