11.522 discussion notes

11.522: UIS Research Seminar (Fall 2007) - Discussion notes

Tuesday, October 23, 2007, 5:00 - 7:00 PM

Urban Stormwater Simulation & Modeling

Discussion Leader: Wanli Fang

Why choose this topic:

Responsible stormwater management has become the subject of increasing public attention not only due to a combination of natural events and government legislation, but also the recognition of the hazards of combined outflow systems and the tremendous financial and ecological cost of end of pipe solutions. Efficient and accurate stormwater modeling capabilities are necessary to support demands for development while minimizing impacts downstream. Looking in retrospect, GIS tools have been largely adopted in large scale landscape planning concerning surface water modeling, but not so full-fledged in guiding site planning in urban context.

Ever since the release of EPA’s original version of SWMM in 1971, the endeavor to develop more powerful stormwater modeling tools never stops. From TR-55, TR-20 and HEC-2 models to SWMM 5.0, StormNetTM and Geo-STORMTM, hundreds of urban stormwater modeling tools have been developed to facilitate the decision making of civil engineers and site planners. Unfortunately, these urban stormwater models seldom have strong ability to deal with detailed spatial information. Given the breakthrough of geo-information technology in the past decades, it is possible and meaningful to expect further improvement to urban stormwater modeling based on GIS platforms.

Overview of discussion contents:

My discussion will start from the increasing demands for stormwater simulation and modeling due to water-related problems caused by urban constructions. To give a brief introduction to modeling concepts, I theoretically categorize urban stormwater models from different perspectives, including spatial and temporal characteristics of model design, complexity of calculation and subfields of modeling capabilities. After that, a comparison of commonly used stormwater models will be given to reveal the general trends in developing stormwater simulating tools. EPA SWMM 5.0 will be used as a specific example to demonstrate the process and outcomes of urban stormwater modeling. Finally, the inefficiency of current models will be discussed and several potential improvements will be included.

Questions for reflection

Are current stormwater models effective in simulating the real world events? If not, what are the main causes of such inefficiency? Are they external limitations or internal deficiency?
Are stormwater models helpful in supporting site planning decisions? What is the gap between the results from modeling tools and the need of planning professionals?
Is it possible to integrate GIS with urban stormwater modeling? If yes, in what way?
Do currently used stormwater modeling tools have good technical compatibility and openness to other software? Why are these characteristics important?
What is the effect of scale (spatial, temporal) on stormwater modeling? Does it tell us anything beyond technological solutions to stormwater problems?