2012 Volume 18 Pages 131-136
An estimation of bed share stress was conducted from the observation data of river bed wave figure on 1981 flood in the Ishikari River. Estimated stress values were compared with those obtained from the law of river bed resistance using widely thus far. It was revealed that estimated stress values were in the range of 1 to 3 and tended to be bigger than those from the hydraulic observation data. It was suggested that stress value from wave figure didn’t made an impact on hydraulic conditions in overall river course, thus values from hydraulic observation data were smaller than values obtained from wave figure. It was also suggested that estimation of roughness coefficient and reflecting it to river planning for disaster reduction should be safe side, consideringf figure dispersion and value range.
