2005 Volume 49 Pages 1339-1344
The Naruse River mouth showed stable topography at least for these 46 years. However, sand bar on the lefthand side of the river mouth has been declining in recent years. The behavior of the morphology of the river mouth after the flushing of the sand bar has never been observed. In this paper, characteristic morphological change at the Naruse River mouth is shown with the use of aerial photographs and morphological maps. In order to determine the main factor of morphological change, empirical orthogonal functions are applied. It is concluded that the decline of the sand bar has occurred by the construction of the headlands. Furthermore, the mechanism of the sand bar intrusion into the river is explained by wave overtopping over the left-hand side sand bar at the river mouth.
