# Characteristics of Summer Flash Drought and Its Effect on Maize Growth in Liaoning Province, China
## 5 Conclusions  
This study examined the incidence and characteristics of summer flash droughts in Liaoning Province using the EDDI. The results showed increasing trends in frequency and intensity, which had a significant impact on the widely planted maize in this area. The assessment of maize growth during the critical development period in three typical flash drought years revealed that summer flash droughts caused a reduction in the total primary productivity of maize to varying degrees. The degree of decline in maize productivity and yield was significantly associated with the onset and duration of the flash drought. A cumulative precipitation deficit was the main cause of flash droughts in the three typical years. The combined action of heat waves and water deficits was the main cause of flash drought exacerbation. The persistent high-pressure anomaly and atmospheric subsidence formed the atmospheric circulation background that contributed to the incidence of flash droughts.  
A summer flash drought occurs in the critical period of maize development. If a flash drought develops into a long-term drought, its impact on maize yield will be more serious. Therefore, if flash droughts occur during the jointing and silking period of maize, especially during the heading and filling period, we must pay close attention to the risk of flash droughts. By adopting irrigation, fertilization, and other technical measures, it will be possible to reduce the effects of flash drought and extremely high-temperature events.  
At present, there are insufficient quantitative studies on the impact of flash droughts on crop growth and production. Many experimental studies have investigated the period of crop sensitivity to conventional droughts, whereas the period of crop sensitivity to flash droughts is mainly derived from remote sensing data or model simulation, and fewer controlled experiments focused on flash droughts have been reported. Therefore, in future research, a comparative study of flash droughts by means of controlled stress experiments is needed to further clarify the difference between the mechanism of influence on crop growth of conventional drought and flash drought.  
[PERSON] and [PERSON] wrote the main manuscript text; [PERSON] analyzed the atmospheric circulation patterns; [PERSON] and [PERSON] contributed to the revision of the manuscript; [PERSON] and [PERSON] processed the data. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Application of Basic Research Plan of Liaoning Province (2023 JHz/101300090, 2022 JHz/101300193), China Meteorological Administration Innovation Development Project (CXFZ2023J055) and Project of Institute of Atmospheric Environment, China Meteorological Administration, Shenyang (2022 SYIAEY8).  
The data on maize area and yield were from the Liaoning Provincial Bureau of Statistics ([[http://ij.ln.gov.cn/~tgj/sjcx/ndsj/](http://ij.ln.gov.cn/~tgj/sjcx/ndsj/)]([http://ij.ln.gov.cn/~tgj/sjcx/ndsj/](http://ij.ln.gov.cn/~tgj/sjcx/ndsj/)), accessed on 1 July 2022). The GPP dataset was provided by the National Tibetan Plateau Data Center ([[http://data.tpdc.ac.cn/home](http://data.tpdc.ac.cn/home)]([http://data.tpdc.ac.cn/home](http://data.tpdc.ac.cn/home)), accessed on 31 July 2022).