气候变暖背景下终霜和低温冷害对阿克苏地区棉花播种出苗影响

Influence of Final Frost and Low Temperature on the Seeding and Emerging Period of Cotton in Aksu Region

基于阿克苏主植棉区1991—2023年逐日气温数据、历史灾情资料和棉花发育期资料,应用线性趋势分析和M-K检验等方法,分析研究区终霜和低温冷害变化特征,以及对棉花播种出苗的影响。结果表明:终霜冻害风险阿克苏棉区最小,靠沙漠南部阿拉尔和东部库车棉区大;4月终霜冻害发生概率,中部阿克苏棉区最低,南部靠沙漠棉区最高,东部棉区终霜危害概率高于南部阿瓦提棉区;终霜期在21世纪发生突变,且提前明显,但终霜偏晚的年份时有发生,对棉花安全出苗构成威胁;低温冷害呈缓慢减少趋势,但21世纪20年代初期频次增多;棉花苗期极端气候灾害事件造成终霜偏晚且常伴随着寒潮降温和持续低温,复合灾害导致棉花影响大、范围广、成灾重。

Based on daily temperature data,historical disaster data,and cotton growth period data in Aksu from 1991 to 2023.Linear trend analysis and M-K test methods are used to analyze the characteristics of changes in final frost and low temperature,as well as their impact on cotton seeding and emerging.The results show that the cotton area in Aksu has the lowest risk of frost damage,while the southern Alar and eastern Kuche in the desert have the highest risk;The probability of frost damage in April is the lowest in the central Aksu,the highest in the desert in the south,and higher in the eastern than in the southern Awati;The final frost period undergoes a sudden change in the 21st century,with a significant advance,but it occasionally occurs in years when the final frost is later,posing a threat to the safe emergence of cotton seedlings;Low temperature shows a slow decreasing trend,but its frequency increased in the 2020s;Extreme climate disasters during the cotton seedling stage result in late frost and often accompanied by cold waves and sustained low temperatures.Composite disasters have a significant impact,wide range,and heavy damage on cotton.