INVESTIGATION INTO THE CHARACTERISTICS OF THE RIVER BED VARIATION AT YATTAJIMA AREA OF TONE RIVER WITH SEDIMENT TRANSPORT OF FINE BED MATERIALS IN THE FLOOD

Abstract

This paper discusses the cause of sediment deposition at Yattajima observatory in Tone River which occurred due to the flood in September 2011, by using the data of river channel deformation obtained by aerial photos and surveying. Meanwhile, the triggers and actual phenomenon of sediment transport is ver- ified by the horizontal 2-D river bed analysis.

By short and long-term river bed analysis, the water level, channel deformation, and the migration of sandbars during the flood could be reproduced. And it is clarified that the main cause of the sediment deposition is the decrease in main channel bed height at Nakanoshima section.