Tadesse leads $1.6M NASA project to predict drought, flood in Africa

Tsegaye Tadesse, center, with a farmer and son at an irrigation demonstration site near Harbu, Ethiopia.
Tsegaye Tadesse, center, with a farmer and son at an irrigation demonstration site near Harbu, Ethiopia.

Tsegaye Tadesse, climatologist and remote sensing expert at UNL's National Drought Mitigation Center, is leading a three-year, $1.6 million, multi-institution NASA-funded project to help predict drought and flood in the Greater Horn of Africa. UNL's portion of the total award is $987,767.

Researchers will investigate which prediction methods work best for the Greater Horn, especially in light of an evolving climate, and will work with decision makers to produce seasonal forecasts that they can use, Tadesse said.

Droughts and floods can have devastating impacts in the region, even when early warning systems are in place, Tadesse said. In 2010, drought caused widespread famine that affected 11.5 million people, even though forecasters had predicted the drought well in advance.

The research team will work with local representatives of disaster relief and food security agencies, extension agents, the Famine Early Warning System and others to see what type of forecasts would be most useful, Tadesse said.

Researchers will focus on developing forecasts at time and space scales that correspond to decision makers' needs. They will also see whether existing tools will allow them to go beyond predicting a wetter season than usual to anticipating an extreme event such as a flood using ground observation and remote sensing information.

Although they are looking for locally relevant patterns, the scope of the inquiry will include global weather patterns.

"Droughts and floods are mainly caused by large-scale ocean-atmosphere-land circulation patterns," Tadesse said. "If we understand how those interactions are working and their time lag, then we can improve predicting what's going to happen at local to regional scale."

The researchers will examine large-scale teleconnections for predictive power in the study region, including the El Niño Southern Oscillation (ENSO), the Pacific Decadal Oscillation, sea surface temperatures in the Indian Ocean, and predictors associated with the Indian monsoon.

The team will also examine state-of-the-art techniques based on climatology, remote sensing, environmental modelling and other forecast methods that can provide early warning of drought or flood conditions. They will evaluate how well state-of-the-art seasonal forecast methods for drought and flood are working in the study region, and how they can help anticipate impacts on crops, communities and other aspects of life. One of the forecast techniques the researchers will evaluate is the satellite and climate-based Vegetation Outlook, or VegOut, an effort led by Tadesse.

Tadesse, who also helped develop the drought center's Vegetation Drought Response Index (VegDRI), is collaborating on this NASA project with researchers from Johns Hopkins University, NASA Goddard Space Flight Center, University of California-Santa Barbara's Climate Hazard Group, the U.S. Geological Survey's Earth Resources and Observation Science Center and Famine Early Warning Systems Network, the International Research Institute for Climate and Society at Columbia University, the University of Wisconsin-Madison, and the University of Nebraska-Lincoln, which is where the drought center is based.

Other UNL researchers are Guillermo Baigorria, School of Natural Resources and Department of Agronomy and Horticulture, Shimelis Beyene, Institute for Ethnic Studies and Department of Anthropology, Brian Wardlow, Center for Advanced Lance Management Information Technologies and School of Natural Resources, and Michael Hayes, drought center and School of Natural Resources.

Tadesse is also involved in related efforts at the drought center that include developing the Quick Drought Response Index (QuickDRI), an integrated approach for rapid response agricultural drought monitoring in the United States funded by NASA, and developing the Vegetation Drought Response Index (VegDRI) model for Canada, funded by Agriculture and Agri-Food Canada.

— Kelly Helm Smith, National Drought Mitigation Center

More details at: http://go.unl.edu/8tb8