Area of Excellence

Supported by Innovation and Technology Fund (ITF) - Project ITS/030/00
Principal Investigators: Prof. JHW Lee and Dr. WP Wang, The University of Hong Kong

VISFLOOD is an interactive software tool for interactive design and analysis of drainage systems.

There are three components of the tool: 1) layout design; 2) water flow simulation; and 3) 3D visualization. In the layout design stage, an interface is provided for the user to design the topological structure and shape geometry, as well as elevation, of a drainage system consisting of a network of culverts and channels. This design information about the drainage system is then fed into a simulation package to produce the water levels, velocities and flows at different points and different time, given the rainfall and water intake parameters. Finally, the drainage system together with the simulated flow in the system are visualized via 3D interactive graphics for design evaluation or for communicating the design prototype to stake holders.

VISFLOOD 0.8 Beta (with the 2D flood propagation demo)

VISFLOOD 0.8 Beta User Manual (MS Windows Help format) which includes tutorials on the use of the software

Tai Hang Tung Storage Tank Scheme (THTSS)

The Tai Hang Tung Storage Scheme (THTSS) is an essential component of the West Kowloon Drainage Improvement - Stage 2 Project that is being implemented to solve the flooding problem in Mongkok, Hong Kong. Instead of digging up roads and widening/adding existing drains, an innovative and economic upstream storage scheme is devised. The plan calls for the construction of a 100,000 m³ underground storage tank below an existing football field. Under design conditions (maximum flow of 110 m³/s), part of the flood flow along the Tai Hang Tung Road culvert (approx. 8 m wide by 2.5 m high) and Tat Chee Road culvert will be intercepted by a system of side weirs. The storm water that overflows into the underground tank will be temporarily stored; the flow diversion/storage serves to attenuate the flood peaks and prevent downstream flooding.

A physical model is used to complement the dynamic wave model, and to study the detailed design of the side weir and junction arrangements. Both the numerical model results and physical model tests show that the THTSS can significantly improve the flood control capacity of the urban storm water drainage system. They also confirm the key features of the flood attenuation, including a predicted back flow from the Boundary Street Nullah into the Tai Hang Tung sewer and the side weir channel overflows. The water level at the flooding black spot is decreased by nearly 1 m.
　

THTSS - No Weir
(wmv format, 7.51MB)

THTSS - With Weir
(wmv format, 9.12MB)

2D Flood Propagation

To simulate the 2D overland flow due to the overflow from a river or open channel, a 2D diffusive wave model is dynamically coupled with the 1D channel flow modelling engine developed for VISFLOOD. This demonstration program uses a section of River Indus in the New Territories, Hong Kong to illustrate the water flow in the river and flood plain adjacent to the channel during a significant rain storm.

With the same navigation operations in VISFLOOD for 1D channel system, users can interactively navigate around the modelled area in 3D after installing and running the demo module.

Flood plain (River Indus, Hong Kong)
(mpg format, 3.17MB)