Effects of ENSO Event on Drought and Flood Disasters and Grain Yield in Anhui Province

Chen Xiaoyi; Yao Yun; Wang Xiaodong; Zhang Hongqun; Duan Chunfeng

doi:10.16765/j.cnki.1673-7148.2023.06.004

Abstract：In order to prevent drought and flood disasters and ensure food security,the relationship between ENSO characteristic quantity,different phases and serious drought and flood(waterlog)years and the effects of ENSO on the grain yield in Anhui Province are analyzed by using the comparison meth-od and chi-square x2 test method as well as the meteorological data from 78 stations,disaster situation and grain yield data from 1971 to 2018.The results show that:(1)Both El Nino and La Nina events occurred from spring to autumn(April to October),and ended before early summer(January to June),with most peaks appearing in winter(November to the next January).(2)The typical years with drought or flood(waterlog)were 11 respectively.The average occurrence was once every 2-3 years,and most of them occurred from the early 1980s to the mid-1990s.(3)The probability of serious drought was high in the year of EL Nino or the next year after La Nina.The influence of El Nino and La Nina events on drought were similar in Anhui Province.The probability of serious flood(waterlog)was high in the next year af-ter EL Nino or in the year of La Nina,and the impact of EL Nino on flood(waterlog)was far greater than that of La Nina.(4)The longer the duration and the greater the intensity of ENSO,the more likely the drought and flood(waterlog)disasters occurred.Drought and flood(waterlog)disasters were more likely to occur during the damping year of ENSO events and after the peak of ENSO events.(5)The main grain yield was mainly reduced during the damping year of EL Nino.In the damping years of La Nina event,the years with the increase and decrease in winter wheat yield were similar,while the yield of rice and maize was dominant mainly by increasing trends.