New 3-D flow interpolation method on moving ADCP data

Water Resources Research, 2011WR010867.

Ryota Tsubaki 1, Yoshihisa Kawahara 1, Yasunori Muto 2 and Ichiro Fujita 3

1 Department of Civil and Environmental Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima 739-8527, Japan

2 Department of Civil and Environmental Engineering, University of Tokushima, Tokushima, Japan.

3 Department of Civil Engineering, Kobe University, Rokkodai, Nada-Ku, Kobe 657-8501, Japan

email: Ryota Tsubaki (rtsubaki@hiroshima-u.ac.jp)

Abstract

A simple but accurate interpolation procedure for obtaining the three-dimensional distribution of three-component velocity data, from moving acoustic Doppler current profiler (ADCP) observation data is proposed. For understanding actual flow structure within a river with complex bathymetry, the three-dimensional mean velocity field provides a basic picture of the flow. For obtaining the three-dimensional distribution of three-component velocity data, anisotropic gridding was introduced in order to remove the random component of measured velocity data caused by the turbulence of the flow and measurement error. A continuity correction based on the pressure equation was used to reduce both random and systematic errors. The accuracy of the developed method was evaluated using three-dimensional flow simulation data from a detached-eddy simulation (DES). By using the procedure developed, the complex flow structure surrounding the spur-dikes section in the Uji River was successfully visualized and explored. The proposed method shows superiorities in both accuracy and consistency for the interpolated velocity field, as compared to the Kriging and Inverse-Distance Weighted (IDW) methods.

Keywords

ADCP • river flow • interpolation • 3-D flow

Paper