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Quantifying Environmental Impact of Drought

A team of researchers formulated a drought index that can capture the biological changes of ecosystems in response to the dynamics of drought intensity.

Led by Professor Ma Zhuguo of the Key Laboratory of Regional Climate-Environment for Temperate East Asia at the Institute of Atmospheric Physics, Chinese Academy of Sciences, his team published their findings in Advances of Atmospheric Sciences.

The team defined a drought index according to the difference between actual and potential evapotranspiration rom both observation and reanalysis data and determined the classifications according to a percentile approach. As a result of global warming ecosystems have been increasingly affected by the stresses of drought. The standardized evapotranspiration deficit drought index (SEDI) was formulated to quantify the impact of drought and can sensitively depict the reaction of vegetation and changes of ecosystems compared with indices based on precipitation and temperature.

“In terms of the role played by evapotranspiration deficit in connecting climate and ecosystem processes, SEDI has the potential of highlighting drought impacts on ecological processes,” says Associate Prof. Li Mingxing, corresponding author of the study.

The performance of SEDI besides three commonly used drought indices (scPDSI, SPI, and SPEI) and soil moisture was examined.

“Our study shows that SEDI can reasonably detect droughts and climatic dry and wet transitions, especially at the monthly scale, and can regenerate climatic long-term trends. Moreover, SEDI is more practical than indices of precipitation and temperature in highlighting biological effects in climate droughts. That is mainly because SEDI involves water and energy processes that can both be affected by the vegetation,” explains Dr. Zhang Xia , lead author of the study.

“In the future, we intend to focus on the potential of quantifying the relationships of ecological processes with dry and wet changes and the use in projections of regional ecological environments with climate change,” adds the team’s PI, Prof. Ma. [APBN]