Abstract
Heavy rain disasters in the Kinu River occurred in September 2015 caused a major disaster such as a collapsed house near the embankment due to the embankment destruction and the overflows resulting therefrom. Since the levee breach occurred during the day, the overflowing flow from the broken levee was recorded by a media helicopter. In this study, an image analysis system was developed to extract quantitative flow information from helicopter video images in which the shooting position and angles change one after another. In the analysis, the images after stabilized were orthorectified, and image flow velocity measuring methods were appropriately applied. As a result, the time change of water entering from the broken levee and the total water volume during the disaster were estimated. In addition, the two-dimensional surface velocity distribution was analyzed to show the spreading of inundated flow.
