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Watersheds may not recover from drought

 作者:Tim J. Peterson,M. Saft, M. C. Peel,

The Millennium Drought (southeastern Australia) provided a natural experiment to challenge the assumption that watershed streamflow always recovers from drought. Seven years after the drought, the runoff (as a fraction of precipitation) had not recovered in 37% of watersheds, and the number of recovered watersheds was not increasing. When recovery did occur, it was not explained by watershed wetness. For those watersheds not recovered, ~80% showed no evidence of recovering soon, suggesting persistence within a low-runoff state. The post-drought precipitation not going to runoff was found to be likely going to increased evapotranspiration per unit of precipitation. These findings show that watersheds can have a finite resilience to disturbances and suggest that hydrological droughts can persist indefinitely after meteorological droughts.

来源:SCIENCE: 372 : 6543 : 745-749出版年: 2021, DOI: 10.1126/science.abd5085