High-resolution modeling of meander neck cutoffs: laboratory and field scales

Frontiers in Earth Science

Earth Science

Zhi Li¹  Bangshuai Han²  Theodore A. Endreny³  Jorge D. Abad⁴  Eliseo Carrisoza⁵  Alejandro Mendoza⁵  Ramon Dominguez⁵ 

[1] Department of Civil and Environmental Engineering, The Grainger College of Engineering, University of Illinois Urbana-Champaign, Urbana, IL, United States;Department of Environment, Geology, and Natural Resources, Ball State University, Muncie, IN, United States;Department of Environmental Resources Engineering, SUNY-ESF, Syracuse, NY, United States;Department of Research, Education and Development, RED YAKU, Lima, Peru;Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico, Ciudad de México, Mexico;

关键词: meandering river;    neck cutoff;    numerical modeling;    bed morphodynamics;    Ucayali River frontiers;   

DOI  :  10.3389/feart.2023.1208782

 received in 2023-04-19, accepted in 2023-08-29,  发布年份 2023

来源: Frontiers

【 摘 要 】

Meandering rivers are distinguished by their characteristic sinuosity, which is subject to modulation through channel cutoff, resulting in the formation of oxbow lakes within the abandoned meander loops. Throughout the evolutionary course of a river, these cutoffs establish a connection between the channel and floodplain systems, both crucial to maintaining the dynamic equilibrium of the river system. Nonetheless, the interactive dynamic between the channel and floodplain and its influence on the transient behavior of the channel’s morphodynamics during a cutoff event are frequently reduced to simplistic representations in computational models. This study introduces a comprehensive numerical model that elucidates the adaptive processes of bed and planform during and subsequent to the inception of cutoff and oxbow lakes. The model is assessed through its application to a laboratory scale cutoff, before being employed to a real-world meandering river, specifically the Ucayali River in Peru, in order to gain understanding into channel development and the intricate patterns of planform dynamics following cutoff events. The model is able to capture the main modes of planform migration, translation and expansion for the case of the bend in the Ucayali River. During the neck cutoff, the model simulates the progression of erosional and depositional waves traveling in upstream and downstream directions respectively, underscoring the importance of incorporating both hydrodynamic and morphodynamic factors in characterizing the river dynamics associated with meander cutoffs.

【 授权许可】

Unknown   
Copyright © 2023 Li, Mendoza, Abad, Endreny, Han, Carrisoza and Dominguez.