Researchers find groundwater availability influenced by previous months’ precipitation
New research from North Carolina State University (NCSU) gives scientists and water resource managers an unprecedented level of detail on how climate and precipitation influence groundwater and surface water levels in the Southeast region of the United States. Researchers have found that the groundwater, primarily from unconfined aquifers, available in any given month is directly influenced by the amount of precipitation that fell in that watershed three months earlier. For example, groundwater levels in April are affected by precipitation that fell earlier in January.
Similarly, streamflow—the amount of water in rivers, streams and other surface waters—is influenced by overall groundwater levels over the previous three months combined. So streamflow in April is influenced by groundwater levels in January, February and March.
"This is the first time we've had this specific understanding of how climate and precipitation influence groundwater and streamflow in the Southeast," said Sankar Arumugam, co-author of a paper describing the study and an associate professor of civil, construction and environmental engineering at NCSU.
“Our findings give water resource managers significantly more information they can use to make planning and policy decisions to better prepare for water shortages or drought by developing management plans that account for both streamflow and groundwater,” Arumugam said.
The researchers evaluated 20 to 30 years of data from 20 watersheds throughout the Southeast region, stretching from Virginia to Florida and westward to Alabama, as well as climate data from the El Niño/La Niña-Southern Oscillation in the tropical Pacific.