ENSO背景下山西忻州7-8月极端降水对玉米产量的影响

Impact of Extreme Precipitation from July to August on Corn Yield in Xinzhou City, Shanxi Province under ENSO Background

利用忻州各县(市、区)42 a 7-8月的降水数据和23 a的玉米产量数据,分析了极端降水对玉米气候产量的影响。结果表明:在1981-2022年期间,忻州及其各县(市、区)7-8月的极端降水指数均呈上升的变化趋势,上升速率由西部向东部逐渐增加;玉米实际单产及趋势产量均呈显著的上升趋势;玉米气候产量与极端降水指数呈正相关,两者间的相关系数在海拔较高地区明显大于平川地区;正极端降水事件发生在拉尼娜结束年的概率明显高于开始年,负极端降水事件发生在厄尔尼诺开始年(或持续年)的概率明显高于结束年;正、负极端降水事件一般与玉米气候产量的丰、歉相对应;因ENSO而发生的极端降水事件使得忻州的玉米气候产量平均下降了15.3 kg/hm^(2),下降幅度近7%。

Based on precipitation data from July to August in various counties(cities,districts)of Xinzhou City in 42 years and maize yield data from 23 years ago,the impact of extreme precipitation on maize climatic yield was analyzed.The results show that during 1981~2022,the extreme precipitation index in various counties(cities,districts)of Xinzhou from July to August has shown an upward trend over time,and the rising rate gradually increases from the west to the east.The actual yield and trend yield of corn show a significant upward trend over time.The climate yield of corn is positively correlated with the extreme precipitation index,and the correlation coefficient in areas with higher elevations is significantly higher than that in areas with flat rivers.The probability of positive extreme precipitation events occurring in the end year of the La Nina is significantly higher than that in the beginning year,while the probability of negative extreme precipitation events occurring in the beginning year(duration year)of the El Nino is significantly higher than that in the end year.Positive and negative extreme precipitation events generally correspond to the high and low yield years of corn climate.The extreme precipitation events affected by ENSO resulted in an average decrease of 15.3 kg/hm^(2) in maize climate yield in Xinzhou,with a decrease of nearly 7%.