河川表面のハイビジョンビデオ映像を用いた吉野川洪水流の流量・流速計測

抄録

In recent years, two non-intrusive river-surface flow measurement methods using video images, the large-scale particle image velocimetry (LSPIV) and the space time image velocimetry (STIV), have been developed by the authors and come to be used in actual river flow situations. These methods are useful because they can be applied to efficient utilization of ITV facilities installed near a river. However, due to the lack of spatial resolution of the conventional video system, measurement accuracy would become not enough when the river width is relatively large or the vertical viewing angle is small. Therefore, for improving the measurement accuracy, we utilized a hi-vision video camera with a resolution four times higher than that of the conventional one and made measurements of the flood occurred in the Yoshino River in 2005. In the analysis, the performance of the two methods was compared and it was confirmed that STIV is more efficient than LSPIV for flood discharge measurement.