NON-UNIFORM SUSPENDED-SEDIMENT TRANSPORT IN KUMAGAWA RIVER UNDER FLOODING CONDITIONS

Abstract

SS Flux, particle size distribution and organic matter ratio under flooding conditions were investigated in the Kumagawa River in which dam removal operating will be conducted for the first time in Japan. The results showed 99% of SS were categorized into silt or clay and median diameter of particles had a tendency to be smaller than that of other rivers. The results of non-uniform sediment rating curve (L=aQ^b) analysis indicated that the coefficient b were closely dependent on particle size. Total SS transports into the estuary were estimated 179*10⁴ ton from April, 2010 to July, 2012 and small silt (23.6~5.07µm) element had the best contribution.