Analysis of Hydraulic Characteristics in the River Mouth with Large Tidal Difference - ADCP Application

Abstract

Hydraulics of the river mouth with a tidal effect and saltwater intrusion is sometimes quite different from that of the river without them. The Han River, the largest one in Korea, has a very wide river mouth connected directly to the sea with a largest tidal difference, nearly a 10m at its maximum. This induces some interesting hydraulic phenomena such as the tidal bores of 1-2m high, large diurnal changes of water stage and velocity, uneven distribution of the flow velocity in the river cross section, and changes in the local flow velocity due to the mixing of freshwater with saltwater. Because of these, it is usually difficult to measure the flow field in the river mouth by using the ordinary methods. In this study, ADCP(Acoustic Doppler Current Profiler) has been used to measure the three-dimensional characteristics of the flow field in the mouth of the Han River. The ADCP used for this study is the one developed by RD Instrument Company.