Forecasting future flooding in the Pacific Northwest
Through an allocation with the National Science Foundation Extreme Science and Engineering Discovery Environment (NSF XSEDE), a national cyberinfrastructure that gives researchers access to advanced digital resources, Hill and his team use advanced computing at the Texas Advanced Computing Center (TACC) to perform their modeling.
“The models we need to simulate year after year of climate data are computationally intensive. They solve key physical equations that govern the transport of water and energy, which requires a fine grid in space and time,” Hill said. “And at the conclusion of our modeling run, we have a multi-year data record of all of these important flooding variables — the raw output is very large.”
Hill has been a TACC user for many years; he began with the Lonestar supercomputer in 2007 and is now using Stampede, one of the most powerful supercomputers in the world.
“My research program changed quite a bit because of those initial projects with Lonestar. Having that kind of access was great because it allowed us to do all these things we couldn’t do before,” Hill said. “I ended up pushing a larger percentage of my research portfolio over towards these parallel computing model studies.”
Results from Hill’s study allowed the researchers to calculate extreme water levels for different locations in an estuarine environment for 10-year, 50-year, and 100-year periods. Then, the water levels were overlaid on a digital model of a particular area to identify the zones of inundation.
The release notes that the findings highlight the need to reconsider flood maps that Oregon city planners use for development. Currently, the maps created for future flood zones only show a spatially uniform water elevation. However, Hill’s main finding is that these assumptions are invalid. His models show that the level of inundation will vary greatly, even in small bays. According to Hill, another interesting finding was that future extreme water levels were due to more than sea level rise, as waves and tides will be amplified in the future.
Although the flood maps are designed to represent a small area, Hill believes this work could be replicated throughout Oregon and other states in the Pacific Northwest.
“Working with TACC through XSEDE and using supercomputers allowed us to test a hypothesis, and apply physical process based models to coastal areas,” Hill said. “Now, with funding from the Oregon Sea Grant we are working to implement a new strategy and make these kind of results available to other areas in the Pacific Northwest.”
— Read more in T. K. Cheng et al., “Climate change impacts on wave and surge processes in a Pacific Northwest (USA) estuary,” Journal of Geophysical Research 120, no. 1 (January 2015): 182-200 (DOI: 10.1002/2014JC010268)
