2008 Volume 52 Pages 1315-1320
The longitudinal distribution of salinity near riverbed and the measuring method of water exchange through the riverbed in a tidal river were investigated. The profile observation results proved the existence of the patch of saline water mass on riverbed. Based on laboratory experiments, the relation between the electrical conductivity of bed material and the salinity of pore water was influenced by fine fraction content and groundwater level at the riverbed. The estimation method of discharge through riverbed surface was successfully established and it was verified by the agreement of calculated salinity with the observed salinity of pore water. The calculation results provided the fact that water exchange through riverbed surface is of the order of 10-3 cm/s. The tidal water exchange was occurred in about 30 cm depth layer from riverbed surface.
