Application of a 1D model for overland flow simulations on 2D complex domains

Authors: ZHANG, YAOXIN - University Of Mississippi; AL-HAMDAN, MOHAMMAD - University Of Mississippi; Bingner, Ronald - Ron; CHAO, XIAOBO - University Of Mississippi; Langendoen, Eddy; O'Reilly, Andrew - Andy; Vieira, Dalmo

Submitted to: Advances in Water Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/22/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Two-dimensional (2D) models are more time-consuming than one-dimensional (1D) models, although they can provide more accurate results. This study proposes a 1D model to act as a surrogate to a 2D modeling approach for rainfall induced flow in order to improve computing efficiency. This 1D model can provide comparable results but with much higher efficiency. To validate the above hypothesis, the Center for Computational Hydroscience and Engineering 1D model, CCHE1D, was used to simulate rainfall-induced flow. A 2D example case was used at both laboratory and field scales to validate and demonstrate the capability of the 1D model for flow simulations on 2D complex domains. The comparisons of the simulation results of the 1D model and the 2D models, demonstrated that the developed 1D model is capable of simulating rainfall-induced flow on 2D domains with high efficiency and comparable accuracy. The 1D model was applied satisfactorily to USDA-ARS Goodwin Creek Experimental Watershed in north-central Mississippi. The study numerically validated the proposed hypothesis, as well as the effectiveness of the generation algorithm of channel networks, through 2D examples and application in both laboratory-scale and field scale by comparing a 1D model and a 2D model. The 1D model will provide a valuable tool in assessing complex systems using simpler computational approaches.

Technical Abstract: Two-dimensional (2D) models for overland flow on 2D complex domains are computationally expensive, often limiting their application for practical problems such as rainfall-induced flooding and soil erosion. To address this issue, a surrogate one-dimensional (1D) model is tested to show whether higher computing efficiency with comparable accuracy to a 2D model can be attained. Numerical simulations are presented using a 1D dynamic wave model for overland flow on two-dimensional (2D) complex domains. This is the second part of the study designed to demonstrate the utility of 1D models under these conditions when applied using a 1D channel network that (1) geometrically covers the whole domain without overlapping and interception, and (2) hydrologically follows the steepest slopes. Several benchmark cases on 2D domains in both laboratory and field scales with complex geometry are used to compare the 1D and 2D model simulations. These numerical simulations demonstrated that by mimicking 2D computational meshes using 1D channel networks, the 1D model is capable of efficiently simulating overland flow on 2D complex domains using 1D channel networks generated by mimicking 2D computational meshes with accuracy comparable to 2D models.