UT scientists to develop new model to explore local climate change impacts

January 22, 2007

AUSTIN, Texas—Researchers at The University of Texas at Austin will use a unique new computer model to study how climate change on the global scale will affect people where they live, on the local scale. The team is building the model with help from a new grant from NASA potentially worth $1.23 million.

Long-term, globally averaged predictions of climate change are important and useful, but what most of us really want to know is, how will climate change affect me and the place where I live?

Will it bring more extreme weather events such as droughts, floods, hurricanes, and ice storms? Will it reduce my community’s water supply for drinking, farming or industry? Will it increase my chances of getting West Nile virus or losing my home to storms? Will my local beaches experience more red tides? Will it affect hunting and fishing? Not only that, most of us want to know what will happen in our lifetimes, not a century from now.

Zong-Liang Yang is an associate professor in the Jackson School of Geosciences at the University of Texas at Austin and the project’s principal investigator. His team will build a computer model that integrates climatic, hydrologic, ecological and atmospheric processes, from the global to the local scale.

Initially, the team will use it to study two specific watersheds, the Nueces and the Guadalupe rivers, both of which funnel water to the Gulf of Mexico. The real power of this model, though, said Yang, is that, with some modifications for the local landscape and human population, it can be applied to many other places around the world, including developing countries that are struggling to sustain growing populations.

Semi-arid watersheds such as the Nueces and Guadalupe are common around the world.

“We have similar areas in China, Africa and South America,” said Yang. “This kind of environment is very sensitive to climate change. So this has big consequences for future adaptation of people living in these places around the world. When people are developing land or building irrigation systems in sensitive areas, this model would help them make intelligent, environmentally friendly decisions.”

Yang noted that people living in northern China are experiencing a water crisis. Explosive population growth, rapid urban development, pollution, and a long-term drought are all factors.

“I would like to apply this model to China,” said Yang. “We just need information on the topography, the river networks and land use changes. We would like to look at those as boundary conditions, but the model framework is the same. Using those boundary conditions, we can address questions of how the huge population growth they’re experiencing will affect water availability in upland areas. We’re also interested in how humans are modifying the landscape. Their use of pesticides and fertilizers are much higher than here in the U.S.”

Yang said the model will not only generate forecasts for how watersheds might change in the future, it will also allow him and others to gain a deeper understanding of fundamental processes.

“Change one element, it will change another and then it feeds back,” said Yang. “You can make forecasts. But you can also study the mechanisms, why it happens. This is something I really hope I can develop in my career over the next 10 years.”

“No one has created this integrated model before,” said Yang. The model will actually be a series of nested models, much like a set of Russian nested dolls, each smaller and more detailed than the one surrounding it.

Global climate models will provide boundary conditions around North America. Nested within that will be a higher resolution domain covering the whole continent, enclosing the Gulf Coast region from Texas to Florida. Finally, within that will be a yet-finer resolution domain covering just two small watersheds of interest—the Nueces and Guadalupe rivers.

Yang and his team will feed the models a wide range of satellite data including rainfall, cloud cover, radiation temperature, aerosols, vegetation cover, albedo and roughness of the surface (which affects wind speed). They will also use satellite measurements of ocean color (which indicate ecological activity of plankton and other microorganisms), temperature and salinity.

The model will run on the supercomputers of the Texas Advanced Computing Center at the University of Texas at Austin, which are among the fastest in the world.

The team consists of six investigators: five from the University of Texas at Austin (Zong-Liang Yang and Guo-Yue Niu in the Jackson School of Geosciences, David Maidment in the Department of Civil, Architectural and Environmental Engineering, Paul Montagna and James McClelland in the Marine Science Institute) and one from the University of Texas at San Antonio (Hongjie Xie in the Department of Earth and Environmental Science).

The team was notified in December, 2006 of the award. The study, funded under NASA’s Interdisciplinary Science Program, is titled: “Using Satellite Data and Fully Coupled Regional Hydrologic, Ecological and Atmospheric Models to Study Complex Coastal Environmental Processes.” The grant period is June 2007 through May 2010.

For more information about the Jackson School, contact J.B. Bird at jbird@jsg.utexas.edu, 512-232-9623.