River bed degradation measurement by degradation sensor during a flood of the Hime River

Abstract

There was a possibility that series of riverbed aggradation and degradation occurred at some breaking points of embankments of the Hime River in the 1995's disaster. But such kind of riverbed fluctuation during the flood we could not observe only with the field survey before and after the flood. Because of this, a new measurement method has been needed to measure the stream traverse for such kind of riverbed fluctuation.
The degradation sensor was newly developed by Public Works Research Institute, Ministry of Construction, and installed Yamamoto observation point at the Hime river. The sensor succeed in the measuring the of riverbed degradation at the first half of flood on September 15, 1999. And surveyed riverbed level after the flood was as almost same level with that of before flood. So it become clear that series of riverbed aggradation and degradation occurred at this point. We simulated the measured riverbed degradation by using an one-dimensional riverbed fluctuate calculation. It shows that the sensor is useful to measure the riverbed degradation during flood.