FIELD OBSERVATIONS OF THE AUGUST 2003 FLOOD IN THE SARU RIVER BASIN

Abstract

Recent problems facing river management include a decrease in the water storage capacity of dam reservoirs due to sedimentation and a lack of continuity in sediment moment from the upper to lower reaches. To clarify the characteristics of substance transported during flooding, we made observations of and collected samples from the Saru River in Hokkaido, which has a reservoir in its middle reaches. In this area, a massive flood occurred between August 9 and 11, 2003. We also observed this particular flood. Since the scale of this flood was very large, we were unable to make observations throughout the duration of the flood. We were, however, able to conduct observations during the first half of the flood and at the end of the flood end. Here we report our observation results.