Environmental Science Division (EVS)a Division of Argonne National Laboratory

Argonne researchers improve urban flood impact assessment using high-resolution radar-derived rainfall data and 2-D hydrodynamic model

July 18, 2017

Flooding hazards can have disruptive impacts on highly populated urban areas and critical infrastructures, causing significant damage to people, properties, and the economy. Predicting flooding hazards and evaluating their impacts on urban areas often have limited success because rainfall patterns and urban flooding responses are highly variable over space and time and there are limited on-the-ground observational data to capture these heterogeneities. In addition, flooding mitigation measures in recent years have been more de-centralized in nature.

EVS earth scientist Eugene Yan and other Argonne researchers recently performed a pilot study for the City of Portland, Maine, with an improved flooding analysis tool, which uses a high-resolution, two-dimensional (2-D) hydrodynamic model with a high-resolution radar-derived rainfall dataset. The radar-derived rainfall dataset at resolutions of 250 m and 10 min was generated using the Python-ARM Radar Toolkit (Py-ART) led by EVS atmospheric scientist Scott Collis. The 2-D hydrodynamic model constructed for Portland incorporates detailed urban features such as buildings, streets, stream channels, hydraulic structures, city storm drain systems, land use and land cover, and any coincident storm surge along the coast near the city. The model predicted flooding flow development, the extent of the inundation area, flow depths and velocities, flooding hazardous levels, and the likelihood of flooding vulnerable locations at a resolution of 15 ft by 15 ft under various storm scenarios.

The flooding analysis tool developed in this study can be readily used to evaluate future urban planning options and any proposed flooding mitigation measures in Portland and to optimize their effects. The results will enable and support a more scientific-based decision making process — better informed decisions about capital improvements to stormwater systems, more systematic land use and development planning in the context of future flooding potential, and new stormwater mitigation programs with both engineered approaches and distributed green infrastructures like rain gardens, green roofs, or bio-swales.

This pilot study is part of the Regional Resiliency Assessment Program (RRAP), which addresses a range of hazards that could be regionally significant for Portland, Maine. The RRAP is led by Department of Homeland Security. Argonne is a partner in the RRAP for Portland, Maine. Other Argonne scientists in this study include Julia Pierce, Vinod Mahat and Alissa Jared of EVS and Duane Verner and Thomas Wall of the Global Security Sciences Division.

Simulation and prediction of urban flooding in the City of Portland, Maine, caused by heavy rain coincident with a storm surge along the coast in April 2007.
Simulation and prediction of urban flooding in the City of Portland, Maine, caused by heavy rain coincident with a storm surge along the coast in April 2007. [Source: Eugene Yan, Argonne National Laboratory]
portrait of Eugene Yan