Comparison of 1D/1D and 1D/2D Coupled (Sewer/Surface) Hydraulic Models for Urban Flood Simulation

• Published in: Journal of hydraulic engineering (New York, N.Y.) Vol. 135; no. 6; pp. 495 - 504
• Main Authors: Leandro, Jorge, Chen, Albert S, Djordjević, Slobodan, Savić, Dragan A
• Format: Journal Article
• Language: English
• Published: American Society of Civil Engineers 01-06-2009
• Subjects: TECHNICAL PAPERS
• ISSN: 0733-9429; 1943-7900; 1943-7900
• DOI: 10.1061/(ASCE)HY.1943-7900.0000037

Recent developments in flood modeling have led to the concept of coupled (sewer/surface) hydraulic models. In this paper two coupled models are examined; a one-dimensional (1D) sewer model coupled with a 1D surface network model (1D/1D) and a 1D sewer model coupled with a two-dimensional (2D) surface flow model (1D/2D). Flow over the terrain is better modeled by 2D models, whereas in confined channels 1D models provide a good approximation with less computational effort. This paper presents a comparison of the simulation results of 1D/1D model and a 1D/2D model. The methodology adopted for setting up the models is outlined and explained in detail as well as the 1D/1D modeling techniques used for reproducing the 1D/2D model results. The surface flow comparison clarifies the limitations of the 1D/1D model and indicates that the definition of the surface pathways, the linking elements sewer/surface, and inclusion of virtual manholes are key factors for setting up a more accurate 1D/1D model.