PLANIMETRIC ESTIMATION OF FLOW DEPTH USING VELOCITY FIELDS

Abstract

 In the planning and design of rivers, it is necessary to know the flow rate during floods and the depth of the foundation depth at which the structure can maintain stability during floods. For this purpose, it is essential to understand the riverbed fluctuations during floods, but methods for quantifying the phenomena in flowing water during floods have not yet been established. Surface velocity is one of the hydraulic quantities that can be obtained even in turbid water during floods. Theoretically, the Mass-Consistent model can be applied to calculate the flow depth from the known surface velocity, and the river bed can be determined through the flow depth. In this study, we developed a method for estimating two-dimensional stream depth based on a continuity equation using a planar velocity distribution as an input value. Numerical experiments have shown that the method can be estimated the flow depth distribution in a flow simulating sandbars, and that the estimation accuracy improves when the weight coefficient is used as a spatial variable. The noise in the input values is tolerated to the same degree as the amplitude of the flow depth.