Experts agree on a universal drought index to combat climate risks

High Plains/Midwest Ag Journal (US): In the "Lincoln Declaration on Drought Indices," 54 experts from all regions of the world agreed this month on the use of a universal meteorological drought index for more effective drought monitoring and climate risk management. A World Meteorological Organization official presented the declaration Dec. 15 at the climate change summit in Copenhagen, because scientists predict that more drought will be one of the results of climate change.

The experts considered the three main types of drought: meteorological, agricultural and hydrological. Standard ways of measuring drought will provide the basis for global communication about drought and will contribute to early warning systems so policymakers and the international aid community can deliver more timely relief.

Experts participating in the Inter-Regional Workshop on Indices and Early Warning Systems for Drought, held in Lincoln, Neb., Dec. 8 to 11, made a significant step in agreeing that all National Meteorological and Hydrological Services around the world should use the Standardized Precipitation Index to characterize meteorological droughts.

"Given the complexity in defining drought historically, the selection of a primary index or measure of meteorological drought is an important step forward," said Donald A. Wilhite, director of the University of Nebraska-Lincoln's School of Natural Resources. "This is a step toward developing early warning systems to improve drought preparedness world-wide."

…The SPI is an index that calculates the probability of precipitation for any selected time scale, based on the long-term precipitation record. SPI values range from more than 2 (extremely wet) to less than -2 (extremely dry), with .99 to -.99 considered the near-normal range. Maps normally depict SPI values as colors, with reds and yellows meaning dry and greens and blues meaning wet….

Dunes in Death Valley, California. Photo taken by User:Urban, Wikimedia Commons, under the Creative Commons Attribution ShareAlike 3.0 License