High-Resolution Simulation of Hydraulic Structures in a Typhoon Induced Urban Flood Event

2020 ◽  
Author(s):  
Yunsong Cui ◽  
Qiuhua Liang ◽  
Gang Wang ◽  
Jian Zeng ◽  
Jinchun Hu
Keyword(s):  
High Resolution ◽  
Flood Risk ◽  
Flood Event ◽  
Hydraulic Structures ◽  
Urban Flood ◽  
Flood Modelling ◽  
Flood Model ◽  
Fully Coupled ◽  
Urban Flood Modelling ◽  
Urban Flood Risk

<p>Due to climate change and rapid urbanization, urban flooding has become one of the major natural hazards threatening the safety of people and their properties and affecting the overall sustainability of cities across the globe, especially developing countries such as China. Flood modelling has now provided an indispensable tool to support urban flood risk assessment and management, and inform the planning of cities that are more resilient to flooding.</p><p>Hydraulic structures, e.g. regulation gates and pumping stations, play an important role in urban flood risk management. However, direct simulation of these hydraulic structures is not a current practice in 2D urban flood modelling. This work presents and applies a robust numerical approach to directly simulate the effects of hydraulic structures in a 2D high-resolution urban flood model. An additional computational module is developed and fully coupled to a GPU-accelerated finite volume shock-capturing urban flood model to directly simulate the highly transient flood waves through hydraulic structures. The improved flood model is applied to  reproduce a flood event induced by Typhoon “Lekima” in 2019 in Yuhuan, Zhejiang Province, China. At 3m resolution, the model is able to simulate the complete process of the flood event in nearly 3.5 times faster than real time, demonstrating the efficiency and robustness of the new fully coupled model for high-resolution food modelling in cities. Further simulations are performed to systemically investigate the effect of hydraulic structures and different operational regulations on flood dynamics and associated risks, demonstrating the importance of directly considering hydraulic structures and their operations in 2D high-resolution urban flood modelling.</p><p></p>

scholarly journals An integrated framework for high-resolution urban flood modelling considering multiple information sources and urban features

2018 ◽  
Vol 107 ◽  
pp. 85-95 ◽  
Author(s):  
Yuntao Wang ◽  
Albert S. Chen ◽  
Guangtao Fu ◽  
Slobodan Djordjević ◽  
Chi Zhang ◽  
...  
Keyword(s):  
High Resolution ◽  
Information Sources ◽  
Urban Flood ◽  
Flood Modelling ◽  
Integrated Framework ◽  
Urban Flood Modelling

scholarly journals Simulation of Hydraulic Structures in 2D High-Resolution Urban Flood Modeling

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2139 ◽  
Author(s):  
Yunsong Cui ◽  
Qiuhua Liang ◽  
Gang Wang ◽  
Jiaheng Zhao ◽  
Jinchun Hu ◽  
...  
Keyword(s):  
High Resolution ◽  
Source Term ◽  
Numerical Approach ◽  
Flood Routing ◽  
Water Model ◽  
Hydraulic Structures ◽  
Flood Modeling ◽  
Urban Flood ◽  
Flood Model ◽  
Coupling Approach

Urban flooding as a result of inadequate drainage capacity, failure of flood defenses, etc. is usually featured with highly transient hydrodynamics. Reliable and efficient prediction and forecasting of these urban flash floods is still a great technical challenge. Meanwhile, in urban environments, the flooding hydrodynamics and process may be influenced by flow regulation and flood protection hydraulic infrastructure systems, such as sluice gates, which should be effectively taken into account in an urban flood model. However, direct simulation of hydraulic structures is not a current practice in 2D urban flood modeling. This work aims to develop a robust numerical approach to directly simulate the effects of gate structures in a 2D high-resolution urban flood model. A new modeling component is developed and fully coupled to a finite volume Godunov-type shock-capturing shallow water model, to directly simulate the highly transient flood waves through hydraulic structures. Different coupling approaches, i.e., flux term coupling and source term coupling, are implemented and compared. A numerical experiment conducted for an analytical dam-break test indicates that the flux term coupling approach may lead to more accurate results, with the calculated RMSE against water level 28%–38% less than that produced by the source term coupling approach. The flux term coupling approach is therefore adopted to improve the current urban flood model, and it is further tested by reproducing the laboratory experiments of flood routing in a flume with partially open sluice gates, conducted in the hydraulic laboratory at the Zhejiang Institute of Hydraulics and Estuary, China. The numerical results are compared favorably with experimental measurements, with a maximum RMSE of 0.0851 for all the individual tests. The satisfactory results demonstrate that the flood model implemented with the flux coupling approach is able to accurately simulate the flow through hydraulic structures, with enhanced predictive capability for urban flood modeling.

scholarly journals TOWARDS A HIGH-RESOLUTION DRONE-BASED 3D MAPPING DATASET TO OPTIMISE FLOOD HAZARD MODELLING

2019 ◽  
Vol XLII-2/W13 ◽  
pp. 181-187 ◽  
Author(s):  
D. Backes ◽  
G. Schumann ◽  
F. N. Teferele ◽  
J. Boehm
Keyword(s):  
High Resolution ◽  
Input Data ◽  
Urban Expansion ◽  
3D Mapping ◽  
Mapping Data ◽  
Data Set ◽  
Urban Flood ◽  
Rainfall Events ◽  
Flood Modelling ◽  
Urban Flood Modelling

<p><strong>Abstract.</strong> The occurrence of urban flooding following strong rainfall events may increase as a result of climate change. Urban expansion, aging infrastructure and an increasing number of impervious surfaces are further exacerbating flooding. To increase resilience and support flood mitigation, bespoke accurate flood modelling and reliable prediction is required. However, flooding in urban areas is most challenging. State-of-the-art flood inundation modelling is still often based on relatively low-resolution 2.5&amp;thinsp;D bare earth models with 2&amp;ndash;5&amp;thinsp;m GSD. Current systems suffer from a lack of precise input data and numerical instabilities and lack of other important data, such as drainage networks. Especially, the quality and resolution of the topographic input data represents a major source of uncertainty in urban flood modelling. A benchmark study is needed that defines the accuracy requirements for highly detailed urban flood modelling and to improve our understanding of important threshold processes and limitations of current methods and 3D mapping data alike.</p><p>This paper presents the first steps in establishing a new, innovative multiscale data set suitable to benchmark urban flood modelling. The final data set will consist of high-resolution 3D mapping data acquired from different airborne platforms, focusing on the use of drones (optical and LiDAR). The case study includes residential as well as rural areas in Dudelange/Luxembourg, which have been prone to localized flash flooding following strong rainfall events in recent years. The project also represents a cross disciplinary collaboration between the geospatial and flood modelling community. In this paper, we introduce the first steps to build up a new benchmark data set together with some initial flood modelling results. More detailed investigations will follow in the next phases of this project.</p>

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