Affiliations: Research Center for Urban Safety and Security, Kobe
University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan. Tel: +81-78-803-6439;
FAX: +81-78-803-6394; E-mail: [email protected] | Kinki Regional Bureau of the Ministry of Land,
Infrastructure and Transport, Osaka, Japan
Abstract: A new PIV method for measuring river surface flows using videotaped
images taken from a helicopter has heen developed. In this method, shifting of
background images while videotaping was effectively corrected using the known
coordinates of fixed points on the image. In low flow conditions, river surface
flows were visualized using rice crackers, while in flood flow conditions
surface ripples generated by the effects of near-surface turbulence and
pressure fluctuation were used as natural unseeded tracers. The performance of
the presented method was verified through its applications to the actual river
flow measurements.
Keywords: Unseeded visualization, Seeding, PIV, River flow, Flood, Helicopter