Muste, M.M.MusteHauet, A.A.HauetFujita, I.I.FujitaLegout, C.C.LegoutHo, H.-C.H.-C.HoHAO-CHE HO2019-12-192019-12-19201403091708https://scholars.lib.ntu.edu.tw/handle/123456789/435956Irrespective of their spatial extent, free-surface shallow flows are challenging measurement environments for most instruments due to the relatively small depths and velocities typically associated with these flows. A promising candidate for enabling measurements in such conditions is Large-scale Particle Image Velocimetry (LSPIV). This technique uses a non-intrusive approach to measure two-dimensional surface velocity fields with high spatial and temporal resolutions. Although there are many publications documenting the successful use of LSPIV in various laboratory and field open-channel flow situations, its performance has not been equally substantiated for measurement in shallow flows. This paper aims at filling in this gap by demonstrating the capabilities of LSPIV to: (a) accurately evaluate complex flow patterns in shallow channel flows; and (b) estimate depth in shallow flows using exclusively LSPIV measurements. The demonstration is provided by LSPIV measurements in three shallow flow laboratory situations with flow depths ranging from 0.05 to 0.31. m. The obtained measurements illustrate the LSPIV flexibility and reliability in measuring velocities in shallow and low-velocity (near-zero) flows. Moreover, the technique is capable to evaluate and map velocity-derived quantities that are difficult to document with alternative measurement techniques (e.g. vorticity and shear stress distributions and mapping of large-scale structure in the body of water). © 2014 Elsevier Ltd.Free-surface flows; Image Velocimetry; Large-scale Particle Image Velocimetry; Overland flows; Shallow flowsFlow visualization; Open channel flow; Stream flow; Two dimensional; Velocimeters; Velocity; Velocity measurement; Free-surface flow; Image velocimetry; Overland flow; Particle image velocimetries; Shallow flow; Measurements; free surface flow; open channel flow; overland flow; shear stress; spatial resolution; vorticityreview10.1016/j.advwatres.2014.04.0042-s2.0-84901975878https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901975878&doi=10.1016%2fj.advwatres.2014.04.004&partnerID=40&md5=727120c747e03d3f5a4b838116aaf7da