1961-2020年新疆棉花花铃期高温热害时空变化特征

Spatiotemporal variation characteristics of high temperature heat damage to cotton during flowering and boll-forming period in Xinjiang from 1961 to 2020

为明确新疆棉花花铃期高温热害的时空分布特征和变化趋势,基于1961-2020年新疆棉花种植区101个气象站点逐日地面气象观测资料、灾情资料、棉花生产资料,选取新疆地区棉花花铃期高温热害指标,采用线性趋势分析、空间插值分析和MK趋势分析等方法,从代际、年际和候尺度分析新疆棉花花铃期高温热害发生频率和强度的时空分布和变化特征。结果表明:1)新疆棉花花铃期高温热害的发生以重度为主,中度次之,各等级高温热害发生频率呈南高北低的空间分布特征,高值区集中在和田地区、巴音郭楞蒙古自治州、吐鲁番市和昌吉回族自治州。2)1961-2020年新疆地区棉花高温热害发生站次比、天数、危害热积温均呈增加趋势,其中南、北疆站次比每10年倾向率分别为2.2%和1.6%,危害热积温每10年变化1.7和1.9℃·d。21世纪10年代高温热害最严重。3)新疆棉花7月1候-9月3候高温热害站次比和发生频率随候序推移呈先增加后减小的趋势,在7月4候-8月1候高温热害发生频率较大;时段Ⅰ(1961-1990年)与时段Ⅱ(1991-2020年)相比,时段Ⅱ站次比最大的候序有提前的趋势,北疆站次比最大的候序由8月1候(29.2%)提前到7月3候(31.6%),南疆由7月6候(28.9%)提前到7月4候(33.2%)。

In order to clarify the spatial and temporal distribution and change trend of cotton meteorological disasters in Xinjiang,based on the daily surface meteorological observation data of 101 meteorological stations,disaster data and cotton production data in Xinjiang cotton planting area from 1961 to 2020,the high temperature heat damage index of cotton flowering and boll-forming period in Xinjiang was selected.The linear trend analysis,spatial interpolation analysis and M-K trend analysis were used to analyze the spatial and temporal distribution and variation characteristics of the frequency and intensity of high temperature heat damage at cotton flowering and boll-forming period in Xinjiang from the decadal,interannual and pentad scales.The results showed that:1)The high temperature damage of cotton in Xinjiang was mainly severe,followed by moderate.The frequency of high temperature damage in each grade was high in the south and low in the north.The high value areas were concentrated in Hotan Area,Bayingolin Mongol Autonomous Prefecture,Turpan Ctiy and Changji Hui Autonomous Prefecture.2)From 1961 to 2020,the station proportion,number of days and hazardous heat accumulation temperature of high temperature heat damage of cotton in Xinjiang showed an increasing trend.The trend rate of station proportion in southern and northern Xinjiang was 2.2%and 1.6%per 10 years,and the hazardous heat accumulation temperature changed by 1.7 and 1.9℃·d per 10 years,respectively.High temperature damage was the most serious in the 2010s.3)From July 1st pentad to September 3rd pentad,the station proportion and occurrence frequency of high temperature heat damage in Xinjiang cotton increased first and then decreased with the passage of pentad sequence,and the occurrence frequency of high temperature heat damage was higher from July 4th pentad to August 1st pentad.Compared with period I and period II,the pentad sequence with the largest ratio of stations in period II tends to advance.The pentad sequence with the largest ratio of stations in northern Xinjiang is advanced from August 1st pentad(29.2%)to July 3rd pentad(31.6%),and that in southern Xinjiang is advanced from July 6th pentad(28.9%)to July 4th pentad(33.2%).