Large‐scale particle image velocimetry for measurements in riverine environments

Abstract

[1] Large-scale particle image velocimetry (LSPIV) is a nonintrusive approach to measure velocities at the free surface of a water body. The raw LSPIV results are instantaneous water surface velocity fields, spanning flow areas up to hundreds of square meters. Measurements conducted in typical conditions in conjunction with appropriate selections of parameters for image processing resulted in mean velocity errors of less than 3.5%. The current article reviews the background of LSPIV and the work of three research teams spanning over a decade. Implementation examples using various LSPIV configurations are then described to illustrate the capability of the technique to characterize spatially distributed two-and three-dimensional flow kinematic features that can be related to important morphologic and hydrodynamic aspects of natural rivers. Finally, results and a critique of research methods are discussed to encourage LSPIV use and to improve its capabilities to collect field data needed to better understand complex geomorphic, hydrologic, and ecologic river processes and interactions under normal and extreme conditions. Citation: Muste, M., I. Fujita, and A. Hauet (2008), Large-scale particle image velocimetry for measurements in riverine environments, Water Resour. Res., 44, W00D19,

Application of an Automated Discharge Imaging System and LSPIV during Typhoon Events in Taiwan

“…In the literature, Polatel [30] found that the velocity index ranges from 0.789 to 0.928 based on a series of laboratory experiments. Besides, Muste et al [10] reported that the velocity index is dependent on the vertical profile of velocity affected by flow aspect ratio, Froude and Reynolds number, micro and macro bed roughness, and relative submergence of large-scale roughness elements. Le Coz et al [20] utilized LSPIV approach to measure flash floods, giving a velocity index of 0.90 based upon available gauging data.…”

“…In recent years, non-intrusive approaches based on radar (e.g., [5]) and/or imaging systems (e.g., [6][7][8][9][10][11][12][13][14][15][16]) have been increasingly applied, providing a safer alternative for measuring flood discharge. Without the needs of human-operated physical sampling and data acquisition, surface velocities are characterized from continuous images of observed (seeded fluid) flows mainly using two types of algorithms, i.e., particle tracers and imagine analyses (e.g., [17]).…”

Validation of large-scale particle image velocimetry to acquire free-surface flow fields in vegetated rivers

“…To obtain a larger amount of data, three consecutive time series were recorded from a fixed position leading to a total of 60 images. This drawback of the camera could be circumvented by using a (high frame rate) video camera instead of a photo camera (Bradley et al 2002;Meselhe et al 2004;Muste et al 2008). During the image recording, the parameters controlling the visualization and illumination of the seeding particles are critical (Stanislas & Monnier 1997).…”

“…To correct the perspective distortion due to the angle between the optical axis of the camera and the plane of the image, orthorectification is required (Creutin et al 2003;Muste et al 2008). In this case, image orthorectification was avoided by placing the optical axis perpendicular to the field of view.…”

Applied the Large Scale Particle Image Velocimetry Technique for Measurement the Velocity of Gravity Currents in the Laboratory

“…New technologies have been developed for discharge and surface velocity measurements due to concerns about flow conditions, costs, accuracy, inaccessible locations, measuring time and the safety of conventional methods. One emerging technology is large-scale particle image velocimetry (LSPIV), which has several advantages over conventional measurement techniques; namely, LSPIV is safer, non-intrusive and provides continuous measurements [5].…”