A daily drought index based on evapotranspiration and its application in regional drought analyses

作     者：Xia ZHANG Yawen DUAN Jianping DUAN Dongnan JIAN Zhuguo MA Xia ZHANG;Yawen DUAN;Jianping DUAN;Dongnan JIAN;Zhuguo MA

作者机构：Key Laboratory of Regional Climate-Environment Research for Temperate East AsiaInstitute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of SciencesBeijing 100049China 

出 版 物：《Science China Earth Sciences》 (中国科学（地球科学英文版）)

年 卷 期：2022年第65卷第2期

页      面：317-336页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：This work was supported by the National Key R&D Program of China(Grant No.2018YFC1508701) 

主　　题：Actual evapotranspiration Potential evapotranspiration Daily drought index Meteorological drought Drought events 

摘      要：With climate warming, frequent drought events have occurred in recent decades, causing huge losses to industrial and agricultural production, and affecting people’s daily lives. The monitoring and forecasting of drought events has drawn increasing attention. However, compared with the various monthly drought indices and their wide application in drought research,daily drought indices, which would be much more suitable for drought monitoring and forecasting, are still scarce. The development of a daily drought index would improve the accuracy of drought monitoring and forecasting, and facilitate the evaluation of existing indices. In this study, we constructed a new daily drought index, the daily evapotranspiration deficit index(DEDI), based on actual and potential evapotranspiration data from the high-resolution ERA5 reanalysis dataset of the European Center for Medium-Range Weather Forecasts. This new index was then applied to analyze the spatial and temporal evolution characteristics of four drought events that occurred in southwest, north, northeast, and eastern northwest China in the spring and summer of 2019. Comparisons with the operationally used Meteorological Drought Composite Index and another commonly used index, the Standardized Precipitation Evapotranspiration Index, indicated that DEDI characterized the spatiotemporal evolution of the four drought events reasonably well and was superior in depicting the onset and cessation of the drought events,as well as multiple drought intensity peaks. Additionally, DEDI considers land surface conditions, such as vegetation coverage,which enables its potential application not only for meteorological purposes but also for agricultural drought warning and monitoring.