Investigators Receive NASA Grant to Study Drought from Space

UC Irvine investigators seeking to improve drought predictability in California and the Western U.S. have been awarded a $1.1 million grant from NASA. The Samueli School team, led by principal investigator Amir AghaKouchak, assistant professor of civil and environmental engineering, will collaborate with the California Department of Water Resources on the four-year project, which will incorporate data from satellite images to improve drought monitoring and prediction in the region.

The UCI team, which includes Samueli School Civil and Environmental Engineering Distinguished Professor Soroosh Sorooshian and Associate Professor in Residence Kuo-Lin Hsu, will integrate satellite observations provided by NASA with new statistical methods developed at UCI. The goal is to improve the reliability of drought early-warning systems. “Current drought outlooks are based on regional climate models that have limited predictability,” AghaKouchak says. “We believe we can improve both drought monitoring and prediction by incorporating model-based data and satellite observations.”

Key to this improved performance is information on precipitation, soil moisture and relative humidity levels, which can be gleaned from the satellite data. AghaKouchak believes that the satellite images, which are already being collected for other purposes, can be analyzed effectively with new algorithms to assist in drought monitoring. “We are doing a lot of basic research to find out how to integrate information that is already available, but not currently being used for drought studies,” he says.

The research won’t predict how much precipitation will occur but rather whether rainfall will be above or below average over a future six-month period. “Even that is still very challenging,” AghaKouchak says.

By collaborating with the California Department of Water Resources, researchers hope to tailor their findings to the agency’s needs – bridging the gap from basic research to information that can be used in decision-making.

The team hopes to unveil its new drought-monitoring system within a year. “We’re just really excited about this opportunity,” AghaKouchak says.

Some of AghaKouchak’s other climate research is also making waves. A paper he wrote with former graduate student Linyin Cheng, which details a new method for anticipating extreme rainfall events in a changing climate, was published recently in Nature’s Scientific Reports.

Cheng, who now works at the National Oceanic and Atmospheric Administration, and AghaKouchak determined that current formulas for estimating the recurrence intervals of extreme precipitation omit important data that can change these extremes.

Their paper, “Nonstationary Precipitation Intensity-Duration-Frequency Curves for Infrastructure Design in a Changing Climate” develops a flexible model that analyzes localized rainfall data while incorporating evolution of existing climate trends. The new method allows researchers to derive non-stationary intensity-duration-frequency curves (known as IDF curves) that take into account increasing the extremes, where applicable.

Another of AghaKouchak’s papers, written with a team of international collaborators, was recently published in the Journal of Great Lakes Research, stirring up additional worldwide interest. “Aral Sea Syndrome Desiccates Lake Urmia: Call for Action” details the damage caused to one of the world’s largest saltwater lakes by development, agriculture, anthropogenic changes and competition for water. Multi-spectral high-resolution satellite observations show a decrease of 88 percent of the lake’s surface since the 1970s, far greater than previously reported. The report made the front page of British daily The Guardian, and is generating interest from scientists around the world.

-- Anna Lynn Spitzer

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