平面2次元流解析とアジョイント法に基づいた点観測の水位情報に対する縦断水面形時間変化の同化手法の検討

抄録

It is important to monitor and estimate the change in the water surface profiles along banks over time precisely, to reduce the flood damage. In this paper, we present the assimilation method the water surface profiles by using the adjoint method into the two dimensional shallow water flow model, and applied the method to two floods in 2011 and 2015 in a reach of Tone River between 133km and 152km.

The shape and elevation of the river and vegetation are measured from a helicopter with Airborne LiDAR Bathymetry (ALB) to make a numerical river model. The rate of flow, roughness coefficients, and permeability coefficients of trees are estimated automatically in the adjoint model. In about 10 times of iterations, the validity of data assimilation of water surface profiles is shown in the computation results.