Modeling coastal flooding in urbanized lowlands: a multi-dimensional high-resolution approach
Brett F. Sanders, ProfessorTimu Gallien, Ph.D. Student
Civil and Environmental EngineeringUniversity of California, IrvineUC Center for Hydrologic Modelinghttp://[email protected]
Sanders Lab, UC Irvine
• Motivation– Coastal flooding from extreme high
tides and waves / sea level rise– Inland flooding from intensified
precipitation/levee failure– Emergency Management– Zoning– Infrastructure Assessment and
Planning• Technology Integration
– Improved coverage and resolution of geospatial data
– High performance computing– Advanced numerical methods
• Predictive models for flood risk management
– Physically representative parameters– High resolution (< 10 m )– Timely
• Developing knowledge base and tools for accurate mapping of flood impacts in topographically complex regions
Aerial LiDAR Spatial Resources
Flood Simulation, Houston, TX
Baldwin Hills Flood DWR
Newport Harbor, CA Study• Flooding from high tides and waves
– Highest tides in winter and summer– Non-tidal anomalies of ~0.3 m can
exacerbate flooding (El Niño storms) – Wave effects magnified at high tide
• Factors affecting flood map accuracy– Tidal amplification– Inventory of flow paths– Vertical accuracy of overtopping
thresholds– Wave setup / wave overtopping flows– Erosion of flow barriers– Routing (hydraulic versus static)
• Findings to date– Static models overestimate flood extent– LiDAR insufficient for overtopping
thresholds• LiDAR vertical accuracy (~15 cm) • RTK survey vertical accuracy (~3 cm)
– Flood extent sensitive to tide height• 4.4 cm tide height bias causes 250%
increase in flood extent Static
January 10, 2005
(Gallien et al., in prep.)
San Francisco Bay, CANOAA Tsunami Inundation DEM (30 m)
Spatially variable grid resolution
Emphasis on topographic features (levees) near mean sea level
SF Bay 2100
South SF Bay 2050
South SF Bay 2100
Simulations2050: 16 inches SLR2100: 55 inches SLRTide: 12 hr period; Great Diurnal Range for SFComputing: ~1 hr on 64 processors
Acknowledgements
• We thank the National Science Foundation (CMMI-Resilient and Sustainable Infrastructure Program) and the UC Water Resources Center for grants that supported this work
• And we thank the City of Newport Beach and Los Angeles County for their gracious cooperation
• http://sanders.eng.uci.edu