Particle-image velocimetry for whole-field measurement of ice velocities

Particle-image velocimetry (PIV) is introduced herein as a useful experimental and field technique for determining and mapping whole fields of ice and water velocities. The technique, which is becoming extensively used in other applications of fluid mechanics, lends itself very well for this purpose. The primary requirements to use the technique are a suitable series of images of moving ice, or model ice in a hydraulic model, a computer equipped with a frame-grabber, and the pertinent software. The images may comprise direct video images, a series of photographs, or radar-generated records of moving ice. The present paper briefly describes the principles underlying PIV and shows how PIV can be adapted for use in hydraulic-model studies of ice-movement problems. The technique is demonstrated for a hydraulic model study of ice movement through a confluence of two rivers. The technique's utility suggests that it also could be a useful adjunct for remote sensing of ice movement on rivers, in coastal regions, or on oceans. (C) 1997 Elsevier Science B.V.