Authors: Reihaneh Zarrabi, Riley McDermott, and Sagy Cohen; University of Alabama; Mohammad Erfani – University of South Carolina
Title: Bankfull Channel Geometry Estimation over the Continental United States (CONUS)
Abstract: The river, a dynamic component of the earth’s nature, can play a significant role in the lives of humans, flora, and fauna. The evolution of river geometry (such as width and depth) under different flow conditions can, in general, have a significant impact on how water and sediment are transported along the channel, which primarily causes flood events to occur, the river ecosystem to alter, and the water quality to change downstream. The research into estimating channel geometry started when Leopold and Maddock proposed a set of power-law equations to predict the hydraulic geometry attributes based on flow discharge (Leopold and Maddock, 1953). A similar methodology, which is known as Regional Hydraulic Geometry Curves, is proposed by Dunne and Leopold to estimate the hydraulics attributes based on drainage area (Dunne and Leopold, 1978). Both highlighted methods are limited by insufficient dataset size and quality, spatial and temporal variability, and lack of consideration of catchment and reach characteristics. This research enhances a large dataset’s quality by removing outlier and noisy observations that may have been reported incorrectly or from locations other than streams. Then, additional filtrations are added to extract a subset of a dataset that includes specific hydraulics geometry attributes for each site that most closely represents the bankfull condition. Afterward, the development of multi-regression models is then done on the extracted subset to overcome the limitations of the existing estimate models and identify the hydrological and catchment features that can influence the estimation of channel geometry at bankfull conditions. Having been created, the models are evaluated and validated. The derived models can be taken into account to estimate the bankfull hydraulics properties of channels over the Continental United States (CONUS), which may be used for generating flood inundation mapping that can be useful in terms of planning and mitigating flood risks.