Distributed modelling of urban runoff using a meta-channel concept

Area of Science:

• Hydrology and Water Resources Engineering
• Environmental Engineering
• Computational Fluid Dynamics

Background:

• Accurate hydraulic flood routing is crucial for urban drainage systems but computationally intensive for 2D pipe networks.
• Existing methods often require detailed, individual calculations for extensive pipe networks, limiting efficiency.

Purpose of the Study:

• To develop and validate a simplified method for hydraulic flood routing in 2D urban pipe networks using the meta-channel concept.
• To enable efficient estimation of runoff from urban catchments by reducing computational complexity.

Main Methods:

• Developed the meta-channel concept to transform a 2D pipe network into an equivalent 1D pipe with effective hydraulic geometry.
• Applied a nonlinear diffusion wave equation, derived from the Saint-Venant equation, for flood routing using an explicit numerical solution.
• Estimated celerity and diffusion coefficients for the Goonja drainage network using the meta-channel concept.

Main Results:

• The meta-channel concept successfully simplified the 2D pipe network into a 1D representation.
• Flood routing using the meta-channel approach showed close agreement with distributed SWMM simulations.
• Results closely matched observed data, confirming the model's accuracy.

Conclusions:

• The meta-channel concept is a viable and effective approach for hydraulic flood routing in urban drainage systems.
• This method significantly simplifies the computational demands of analyzing 2D pipe networks.
• The study demonstrates the applicability and efficiency of the meta-channel concept for urban runoff estimation.