Hydrodynamic Interpolation Method of Submerged River Bed Topography for Laser Scanning Survey

Abstract

フェロー会員 工博 広島大学教授 大学院工学研究科(同上) 3 学生会員 広島大学工学部第四類(同上) 4 非会員 復建調査設計株式会社 空間情報システム部(〒732-005広島県広島市東区光町ニ丁目10-11)Recently 3D laser scanner systems have been widely and effectively used to measure the physical environment of river. However, it is still very difficult to obtain submerged river bed topography. To overcome this problem, this paper proposes a new and practical method to interpolate the submerged bed elevation to compensate for the weak points of laser systems. First, we obtain the detailed bed data in an experimental channel by a laser scanner system. The performance of a geometric interpolation method using bed elevation and its gradient at water edges is discussed. Then we show the significance of water surface profile in estimating river bed profile through the comparisons between the interpolated and the measured data. And we formulate a new hydrodynamic interpolation method of river bed topography under water surface using water surface profile. The hydrodynamically interpolated submerged bed river shape is found to show good agreement with the measured data.