北方枣区果实成熟期连阴雨致灾因子的时空变化特征

Spatio-temporal variation characteristics of disaster causing weather of continuous rain at fruit maturation period in northern jujube production areas

北方枣区是我国枣果主产区,果实成熟期连阴雨是枣树生育期影响产量品质最主要的气象灾害。利用北方枣区53个站点1971-2019年果实成熟期逐日气象资料,运用线性倾向分析法和ArcGIS空间分析技术,分析北方枣区果实成熟期连阴雨累积次数、连阴雨累积日数、连阴雨累积降水量和连阴雨平均相对湿度四个致灾因子的时空变化特征,为北方枣区枣果生产区划提供依据。结果表明:1)在研究时段内,北方枣区果实成熟期连阴雨站次比年际间变化很大,总体上呈上升趋势。2)北方枣区果实成熟期的年连阴雨累积次数、年连阴雨累积日数、年连阴雨累积降水量和年连阴雨期间平均相对湿度年际间变化很大,总体上呈轻微上升趋势;北方枣区枣果成熟期连阴雨各致灾因子年代际变化整体上在20世纪70年代到90年代呈明显降低的趋势,20世纪90年代到21世纪10年代呈显著增加的趋势。3)在空间分布上,北方枣区果实成熟期连阴雨累积次数、连阴雨累积日数、连阴雨累积降水量和连阴雨期间平均相对湿度值以新疆枣区最小,甘肃中西部枣区和宁夏枣区次之;在其东部,从北到南大体呈现逐渐增大的趋势。

Jujube production regions in northern China is the main production area of jujube in China.Continuous rain during fruit ripening period is the main meteorological disaster affecting yield and quality during jujube growth period.Based on the daily meteorological data of the fruit ripening period from 1971 to 2019 at 53 stations in the northern jujube area,using the linear trend analysis method and ArcGIS spatial analysis technology,the spatial-temporal variation characteristics of the four disaster causing factors:cumulative times of continuous rain,the cumulative days of continuous rain,the cumulative precipitation of continuous rain,and the average relative humidity of continuous rain during the fruit ripening period in the northern jujube producing areas were analyzed,so as to provide a basis for jujube production in the northern China.The results showed that:1)During the study period,the station to station ratio of continuous rain changed greatly from year to year in the fruit ripening period in the northern jujube producing areas,and showed an upward trend on the whole.2)The cumulative times of continuous rain,cumulative days of continuous rain,cumulative precipitation of continuous rain and average relative humidity during continuous rain varied greatly from year to year,showing a slight upward trend overall.The interdecadal variation of each disaster causing factor in the mature period of jujube fruit in the northern jujube producing region showed a significant decreasing trend from the 1970s to the 1990s,and a significantly increasing trend from the 1990s to the 2010s.3)In terms of spatial distribution,the values of four factors were all the smallest in Xinjiang jujube producing area,followed by central and western Gansu and Ningxia jujube producing regions.In the eastern region,it generally showed a gradually increasing trend from north to south.