西南地区水稻高温热害时空特征及危险性

Spatial-temporal Characteristics and Risks of High-temperature Heat Damage of Rice in Southwest China

基于西南地区1980−2022年351个气象站点逐日气象资料,以水稻关键生育期(抽穗灌浆和灌浆成熟期)为研究时段,基于高温热害累计指数分析西南地区高温热害时空变化规律及其危险性,为当地水稻种植合理布局提供理论依据。结果表明:1980−2022年西南地区水稻两个关键生育期高温热害发生站次比年际变化均呈显著增加趋势,每10a增加速率分别为6.4个百分点和4.1个百分点。从年代变化来看,水稻两个关键生育期在20世纪80年代高温热害发生相对较轻,发生总数站次比为16.3%和7.8%;近13a高温热害发生较重,总数站次比分别为38.1%和22.2%。水稻两个关键生育期发生高温热害最多年份均为2022年,发生站次比分别为51.6%和37.6%。西南地区抽穗灌浆期水稻高温热害年倾向率增幅较大,主要集中重庆中、西部,贵州东部以及四川盆地东北部和南部,仅零星站呈减少趋势。水稻灌浆成熟期高温热害年倾向率在四川盆地、重庆大部地区呈显著增加。水稻两个关键生育期高温热害发生日数、频率和危险性空间分布大体一致,均呈东北高、西南低的态势;高发区主要集中在重庆中西部和北部、四川盆地东北部、盆中和盆南地区。本研究实现了高温热害评估定量化,提高了空间分布的精细度,对当地水稻实际生产更有指导性。

High-temperature and heat damage is the major agricultural meteorological disasters in southwest China,and it is important to study them to ensure rice production.Based on daily meteorological data from 351 meteorological stations in the southwestern region from 1980 to 2022,this study focused on the critical growth stages of rice(heading-milk grain stage and milk grain-mature stage)to analyze the spatial and temporal variations and risk of high-temperature and heat damage using the heat damage cumulative index.The results provide a theoretical basis for the rational placement of rice cultivation.The results showed a significant increase in the number of stations experiencing high temperatures and heat damage between 1980 and 2022 during two critical growth stages of rice,with the increasing rates of 6.4 and 4.1 percentage points per decade.Taking a decade-by-decade perspective,heat stress and damage were relatively light in the 1980s,with the total number of stations experiencing heat stress during the two growth phases being 16.3%and 7.8%of the total number of stations,respectively.However,the high-temperature and heat damage were more severe in the last 13 years,with a total number of stations experiencing heat damage accounting for 38.1%and 22.2%of the total stations.The year with the highest occurrence of high-temperature and heat damage during both growth stages was in 2022,with the total number of stations experiencing heat stress accounting for 51.6%and 37.6%of the total stations,respectively.The annual tendency rate during the heading and milking stage had inceased significantly in the southwestern region,mainly concentrated in the central and western parts of Chongqing,the eastern part of Guizhou,and the northeastern and southern parts of the Sichuan basin.Only a few stations showed a decreasing trend.The tendency rate during the ripening stage of rice increased significantly in most areas of the Sichuan basin and Chongqing.The spatial distribution of the number of days,frequency,and risk of high-temperature and heat damage during the two critical growth stages of rice were generally consistent,showing a high concentration in the northeast and a low concentration in the southwest.The high-risk areas of high-temperature and heat damage were mainly concentrated in the central and western parts of Chongqing,the northern part of Chongqing,the northeastern part of the Sichuan basin,and the central and southern parts of the basin.This study achieved a quantitative assessment of high temperature and heat damage,improved the fineness of spatial distribution,and provided more guidance for actual rice production.