河口干潟と砂州の底質移動に及ぼす潮汐流の効果

抄録

Sediment transport phenomena at a tidal flat and a bar of a river mouth were discussed. Study site was the mouth of YOSHINO River, Shikoku Island in Japan. First, field observations were carried out to measure the amount of sediment transport during a tide. Secondly, tidal flow simulations were conducted to clarify space-time variation properties of friction velocity at the tidal flat. Finally, the amount of sediment transport was calculated by using the formulae based on bed load transport. Main results are as follows: 1) The sediment transport at a tidal flat not only changes spatially but also is greatly different according to a tidal range. 2) A friction velocity becomes large when a tidal flat has just dried up or flooded. 3) The transport rate of sediment which diameter is between 40 and 200 μm was able to estimate by using the bed load formulae.