By Douglas Esser
Sometime, about 50 years from now, a threatening storm probably will push out of the South China Sea into southeast China鈥檚 Pearl River Delta, a densely populated region that includes Hong Kong, Macao and Zhuhai. Historically, the storms known as mei-yu (鈥減lum rains鈥�) cause dangerous flooding.
By 2070, the rains are expected to be even more intense because, in a warmer climate, the atmosphere will hold more moisture. A flash flood could be deadly. But, a downburst on the delta could be absorbed without serious flooding 鈥� thanks to 鈥渟ponge city鈥� planning based on simulations to be completed in 2020 by Eric Salath茅, a climate scientist at the 56吃瓜网.
Simulating every drop
Eric Salath茅 56吃瓜网 Bothell Salath茅, an associate professor in the School of Science, Technology, Engineering & Mathematics, received a $130,000 grant through Tsinghua University for a modeling project called 鈥淩egional Climate Simulations for Eastern China: Support for Sponge City Designs.鈥� Salath茅 is developing the computer model in collaboration with Nian She. He is director at the Smart Utility Research Institute of Tsinghua University鈥檚 Innovation Center in Zhuhai. Salath茅 has been there twice. A modern-looking subtropical city with palm trees, it reminds him of Miami. Salath茅 previously worked with She when he was a senior civil engineering specialist with the city of Seattle. When She returned to China to do urban design, he connected with Salath茅 again to ensure the designs would be sustainable during climate change. The climate simulation will next go into engineering models for more permeable stormwater systems. 鈥淭hen they can say, instead of a parking lot, let鈥檚 put in a rain garden. Instead of paving curb-to-curb, put a green strip down the middle. Or they can say, let鈥檚 make this storm drain bigger or put a tank here,鈥� Salath茅 said. 鈥淪o, every drop is intentionally managed.鈥�
Expertise for the future
Eric Salath茅 in China. courtesy photo Salath茅 is especially qualified for the work because of his expertise in climate change and extreme weather events. Before joining 56吃瓜网 Bothell in 2010, Salath茅 worked with the Climate Impacts Group at the 56吃瓜网 in Seattle. A weather modeling group led by 56吃瓜网 Atmospheric Sciences Professor Cliff Mass is also collaborating on the Zhuhai project. 鈥淢y work is basically similar to what they do for weather forecasting except that I鈥檓 50 to 100 years into the future, rather than next week,鈥� Salath茅 said. 鈥淲e don鈥檛 know exactly when the storms are going to occur, but we can talk about the probability of different kinds of events in the future.鈥� Salath茅 teaches physics and climate science in 56吃瓜网 Bothell鈥檚 Physical Sciences Division. He eventually hopes to engage undergraduate students in converting climate model data into more easily visualized charts and graphs with interactive web tools. The simulations of the Pearl River basin climate are based on data compiled since 1980 and trend projections out to 2070. One year into the two-year project, the model is running on a supercomputer in China. Findings so far are preliminary.
Looking far away at the very small
Salath茅 has reason to believe the effects of climate change will be most obvious in the intense, shortest duration rainfall events. His model makes distinctions in periods of less than an hour and over a distance as small as 20 kilometers (12 miles). That鈥檚 in contrast to global models that use regional averages. 鈥淲e really have to simulate these short duration, high intensity events in detail to understand the effects of climate change,鈥� Salath茅 said. 鈥淲e鈥檙e looking way in the future at things that are very short and very small.鈥�
