THE INFLUENCE OF SUBSURFACE FLOW TO THE RIVERBANK EROSION

Abstract

The water level of a river in the monsoon region decreases largely in the dry season. It is known that riverbank erosion occurs in the low water level, and it is considered that the subsurface flow influences it. We obtained particle diameters and hydraulic conductivities from some samples by field survey in the Mekong River side. Critical velocity and circular slip surface are used for analysis of riverbank erosion process. It is found that some places have effects on subsurface flow to riverbank erosion according to particle kinds distribution. This distribution is estimated by numerical simulation of subsurface flow. Finally, we defect the influence areas from river mouth.