低纬高原水稻抽扬期低温冷害指标及其时空变化规律研究

Study on Chilling Damage Index of Rice and Its Spatial-temporal Variation of Low-latitude Plateau during Heading and Flowering Period

针对云南水稻抽扬期低温冷害,结合云南气候特点,采用气象数据、空壳率数据,应用相关分析及抽象模拟等方法,确定云南低纬高原地区水稻抽扬期低温冷害指标,并应用该指标分析云南水稻抽扬期低温冷害时空分布规律。结果表明,日最高气温<24℃3d以上,即可能发生水稻抽扬期低温冷害。滇西北中北部、滇东北中南部低温冷害频率发生频繁,每10年达14次以上,基本上每年都会发生低温冷害;滇西南南部低温冷害发生频率较低,每10年在2次以下,其余地区每10年发生2~8次低温冷害。从年代际特征来看,低温冷害变化规律明显,总体呈减弱趋势,其中20世纪70年代、90年代较重,2000年后低温冷害频率大幅下降。

For the chilling damage of rice during heading and flowering period in Yunnan, combined with the characteristics of Yunnan climate, meteorological data and shell rate data of rice were adopted to establish the chilling damage index of rice in Yunnan by correlation analysis and abstract simulation, etc., the temporal and spatial distribution of rice chilling injury in Yunnan during heading and flowering period was analyzed.The results showed the daily maximum temperature was less than24 °C for more than 3 days, which may cause chilling damage during heading and flowering period of rice.The frequency of chilling damage in the north-central of northwest Yunnan and south-central of northeast Yunnan was frequent,it reached 14 times per 10 years, and basically, chilling damage occurred every year.The chilling damage occurred less in south of southwest Yunnan , which occurred less than2 times every 10 years.The rest of the region had two to eight times every 10 years.From the interdecadal characteristics, the chilling damage changed obviously, and the overall trend was decreasing.The 1970s and 1990s were heavier, and the chilling damage was greatly reduced after2000.