潮汐影響のある河川の水深計測について

抄録

In South East Asia, there are many rivers that are suitable for transportation. However, at the end of rainy season, a large amount of sedimentation arises in the river. It causes frequent accidents such as groundings. Therefore, those rivers need to be dredged for the safety navigation. For this purpose, it is very important to measure the water depth timely and easily. However, it is still difficult to measure water depth in wide area. The authors have proposed a simple method. The measurement of water depth of the river using Kinematic GPS (K-GPS) and sounder is investigated. However, the tidal effect should be taking into an account for the precise measurement. The tide level of each measurement point was estimated by linear interpolation from tide tables. Substituting thus estimated tide level from the measured surface altitude of the river surface by K-GPS, river chart datum of each point was estimated. Thus estimated chart datum on downstream-bound and upstream-bound coincide well, and the proposed method of eliminating tide was verified. Therefore it is able to obtain the river water depth combining the tide information and measured sounder data.