Incorporating Network Scale River Bathymetry to Improve Characterization of Fluvial Processes in Flood Modeling

Abstract

River bathymetry is critical for simulating fluvial hydrodynamics accurately in flood inundation mapping. Several studies have investigated the impact of poor bathymetric representation on one-dimensional and two-dimensional flow models and concluded that river bathymetry affects hydraulic attributes significantly. Specifically, inaccurate estimation of channel storage capacity may lead to errors in predicting the depth and extent of inundation. Similarly, errors in estimating longitudinal slope affect the magnitude of streamflow and erroneous thalweg representation can contribute to poor estimation of shear and velocity (

Incorporating Network Scale River Bathymetry to Improve Characterization of Fluvial Processes in Flood Modeling

“…This section gives a brief explanation of the procedure followed by SPRING to estimate river geometry for individual reaches. For more details, please refer to Dey (2016) or Merwade, (2004).…”

“…(a) The input data sets; (b) estimating meandering thalweg from the radius of curvature of river centerline using Equation ; (c) estimating asymmetric cross‐sections using Equations and ; and (d) creating a mesh to generate 3D representation of individual reaches. Note: Part of the figure is adapted from Dey (2016).…”

“…Specifically, inaccurate estimation of channel storage capacity may lead to errors in predicting the depth and extent of inundation. Similarly, errors in estimating longitudinal slope affect the magnitude of streamflow and erroneous thalweg representation can contribute to poor estimation of shear and velocity (Cook & Merwade, 2009; Dey, 2016; Dey et al., 2019; Grimaldi et al., 2018; Saleh et al., 2012). However, these studies have only focused on the influence of river bathymetry on hydrodynamic simulations, usually along a single reach, and not the entire river network.…”

GPU‐Accelerated Urban Flood Modeling Using a Nonuniform Structured Grid and a Super Grid Scale River Channel

“…In fact, no technology exists for obtaining accurate and detailed measurements of the entire bottom surface for all types of rivers in a flood study (National Research Council, 2009), and bathymetric LiDAR and photogrammetry are limited to shallow and clear river reaches only. Though the GPS‐equipped boat‐mounted surveying techniques which utilize echo sounders are more convenient, a minimum water depth that the boat can access is required, and measurements are only taken along the path of the boat (Dey, 2016). Given the challenges of field surveys and remote sensing, conceptual models that can estimate bathymetry from readily available input parameters have become quite popular.…”