Abstract
We propose analytical methods using satellite data to regress effluent axis with the weighted least squares method, and estimate the influence of river effluent on the ambient sea through the distance along the axis in arange between the river mouth and the downstream boundary of diffusion area. As examples the effluents from the Shingu river are analysed and show that the diffusion area estimated through water temperature may differ from that through water turbidity, especially when the discharge rate at the mouth is small. It is considered that turbidity distribution is under the influence of suspended soil particles washed out at the sand bar or beach near the mouth. The salinity is also one of indispensible parameters demonstrating the behaviors of density currents such as the river effluent, and we estimate it through the ratio of TM-band 1 to band 3.
