1961-2019年河南省寒潮时空分布及其对农业的影响

Spatial-temporal Distribution of Cold Wave and Its Influence on Agriculture in Henan Province During 1961-2019

利用1961-2019年河南省111个国家级气象站日最低气温资料和1978-2019年气象灾情资料,分析了河南省寒潮时空分布及其对农业的影响。结果表明:(1)河南省寒潮频次的空间分布表现为豫北和中东部地区的多,豫西和豫南的少。寒潮平均最大降温幅度的空间分布表现为从西北向东南增加,豫北、中西部和豫西南大部的小,豫东和豫南大部的大。(2)近59年来河南省出现了区域性寒潮过程213次,其中秋季发生频次最高,冬季和春季的相同。近59年全省寒潮频次呈显著减少趋势,但2011年以来寒潮频次明显增多。(3)近59年全省强、中、弱等级寒潮过程分别出现39次、121次和53次,冬季强寒潮比例最大,春季和秋季弱寒潮比例最大。强、中寒潮频次总体随年代减少,弱寒潮频次无明显的变化特征。寒潮过程持续日数以1~4 d为主,寒潮强度越强,持续时间也越长。(4)近42年河南省寒潮冻害造成的农作物受灾面积呈不显著的减少趋势,受灾率的空间分布差异较大,豫北大部、豫西三门峡、豫东开封和商丘、豫南驻马店和信阳大部受灾率较大。由于2011年以来寒潮频次明显增加,且寒潮在3、4月份发生频次较大,此时正值农作物生长关键期,抗寒能力较弱,遭受寒潮冻害的风险仍然很大。

Based on the daily minimum temperature data of 111 national meteorological stations in Henan province from 1961 to 2019 and meteorological disaster data from 1978 to 2019,the spatial-temporal distributions of cold waves and its influence on agriculture are analyzed.The results show that:(1)The spatial distribution of cold wave frequency is higher in the north and east-central Henan,while that in the west and southern Henan is less.The spatial distribution of average maximum temperature cooling amplitude during cold waves increases from northwest to southeast in Henan.The maximum temperature cooling amplitude in northern,western and southwest most part Henan is small,but that in eastern and southern most part Henan is obviously large.(2)There were 213 regional cold wave processes experienced in recent 59 years.During the 59 years,the occurrence frequency is the highest in autumn while the frequencies in winter and spring are alike.The frequency of cold waves shows a significant decreasing trend,but since 2011,the frequency of cold waves increases greatly.(3)In recent 59 years,the strong,medium and weak cold waves occurred 39,121 and 53 times,respectively.In winter,the proportion of strong cold waves is the largest,but in spring and autumn,the proportion of weak cold waves is the largest.The inter-decadal frequency variation of strong and medium cold waves shows a decreasing trend,while the frequency of weak cold waves has no obvious variation features.Most cold waves last 1—4 days,and the duration of the cold wave increases with its intensity increase.(4)In recent 42 years,the disaster area of crops caused by cold wave shows an indistinctive decreasing trend,and the spatial distribution of damage rate is quite different.The damage rate is higher in most parts of northern Henan,Sanmenxia in western Henan,Kaifeng and Shangqiu in eastern Henan,Zhumadian and Xingyang most part in southern Henan and Shangqiu in eastern Henan,etc.Since 2011,the frequency of cold waves has increased significantly,and the frequency is higher in March and April(Spring),which is the critical period for crop growth,so the risk of cold wave freezing damage is still very high.