辽宁省大豆主要发育阶段高温干旱复合事件变化特征及其对产量的影响
Variation characteristics of high temperature and drought compound events during the main growth stage of soybean in Liaoning Province and their effects on yield
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摘要: 利用辽宁省51个气象站1961—2020年逐日气象资料及大豆发育期观测数据,基于大豆发育期界限温度与日尺度标准化前期降水蒸散指数(SAPEI),对高温、干旱灾害进行识别,并分析了大豆全生育期及各发育阶段高温干旱复合事件的时空分布特征、变化趋势及其对产量的影响。结果表明:大豆全生育期内,高温干旱复合事件发生范围呈先降后升的变化趋势,多年平均发生范围IOC值为0.37;事件发生频率由西北向东南递减,大部分区域发生频率≥50%,约为两年一遇。在大豆各发育阶段中,播种至分枝阶段,易出现大范围高温干旱复合事件,且IOC呈波动上升趋势,发生频率较高,约为五年一遇;而分枝至成熟阶段,高温干旱复合事件发生频率低且发生范围小。2000年,辽宁省大豆需水关键期发生高温干旱复合事件,发生范围IOC值达0.78,HDD为86.25 ℃·d,旱积指数为-23.42,对大豆最终产量产生显著影响,减产率为7.7%。综上,辽宁省大豆高温干旱事件具有明显的地域差异性与发育阶段差异性。Abstract: Utilizing daily meteorological data collected from 51 stations across Liaoning Province from 1961 to 2020,combined with soybean development stage observation information,this study systematically identifies high temperature and drought disasters based on threshold temperatures for soybean development and employing the Standardized Antecedent Precipitation Evapotranspiration Index (SAPEI) on a daily scale.The spatiotemporal distribution characteristics,variation trends,and impacts on yield of high temperature and drought compound events during the entire growth period and different developmental stages of soybean are analyzed.The results show that these events have had significant impacts on soybean yields.Specifically,the occurrence range of high temperature and drought compound events during the entire growth period exhibits a trend of initial decline followed by an increase,with a multi-year average occurrence range (IOC) of 0.37.The frequency of occurrence gradually decreases from northwest to southeast,with the majority of areas experiencing an occurrence frequency of ≥50%,corresponding to approximately once every two years.During the development stages of soybean,from sowing to branching stage,a large range of high temperature and drought compound events were prone to occur,and the IOC showed a fluctuating upward trend,with a high frequency of occurrence,about once in 5 years.From branching to mature stage,the occurrence frequency of high temperature and drought compound events is low and the occurrence range is small.In 2000,a high temperature and drought compound event occurred in the critical period of soybean water demand in Liaoning Province.The IOC value of the occurrence range was 0.78,the HDD was 86.25 ℃·d,and the drought accumulation index was -23.42,which had a significant impact on the final yield of soybean,with a yield reduction rate of 7.7%.In summary,the high temperature and drought events of soybean in Liaoning Province have obvious regional differences and developmental stage differences.
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