基礎水理・数値解析

[II-118] Points to Consider in 1D Hydraulic Analysis of Rivers with Repeated Joint and Tributary

〇Tadashi Higashide¹, Tsuneaki Shimonaru¹, Akio Yasui¹, Masayuki Sugiura¹, Masahiro Tamai² (1.NIPPON INSIEK, 2.Osaka Sangyo University)

Keywords:joint and tributary, iRIC, HEC-RAS

For the hydraulic analysis of a tributary, the continuity condition of the water level at the tributary point is used. However, the result may be different from 2D analysis. Therefore, a hydraulic analysis of the tributary was conducted using a plane 2D analysis model and compared with 1D analysis. As a result, there was a water level difference at the confluence. Especially, when the tributary is on the downstream of a large-curved river, the water level of the tributary on outer bank tends to be high. With 1D analysis, it is essential to analyze the diversion point considering the water level difference between the right and left banks.