广西高温灾害致灾因子时空分布特征分析

Analysis of the spatial-temporal distribution characteristics of high-temperature disaster-inducing factors in Guangxi

利用1978—2020年广西91个国家气象观测站和有温度观测的1598个区域气象观测站资料,分析了高温日数、高温过程次数、极端最高气温、高温过程平均和最长持续时间、高温过程平均最高气温等高温致灾因子的时空分布特征。结果表明,广西全区年均高温日数19 d,高温过程次数为4次,平均持续时间为6 d,年高温日数、过程发生次数平均每10 a以2.6 d、0.8次的速率显著增多。极端最高气温较高值主要集中分布在桂西、桂北的平原地区,部分地区在40℃以上,中部、沿海地区及海拔较高的山区较低;年高温过程次数桂北和桂中山区、桂东南及沿海地区比其他地区少;高温过程平均最高气温桂西比桂东高,河谷地区比平原高,平原比沿海高。在全球气候变暖的背景下,广西高温灾害天气过程具有范围广、持续时间长、极端性强等特点,主要是由于副热带高压、热带气旋、西南热低压等天气系统影响造成的,大气环流异常则是造成高温极端性强的主要原因。

Based on the data of Guangxi 91 meteorological stations and 1598 temperature observation automatic weather stations from 1978—2020,the spatial-temporal characteristic of high-temperature disasterinducing factors were analyzed,including high-temperature days,high-temperature process times,extreme maximum temperature,high-temperature process mean and maximum duration,average maximum temperature of high-temperature process.The results show that annual average high-temperature days were 19 d,high-temperature process times were 4 times,high-temperature process mean duration were 6 d.Annual average hightemperature days and process times increased obviously that the rate were 2.6 d and 0.8 times of 10 years respectively.The higher values of extreme maximum temperature were mainly distributed in the plain areas of western and northern Guangxi.Annual high-temperature process times in the north,central mountainous region,the southeast and coastal region were lower than the other region.Average maximum temperature of high-temperature process in the west were higher than that in the east,high temperature weather above 40℃occurred in some areas.That in valley region was higher than that in plain region,and that in plain region was higher than that in coastal region.Under the background of global warming,high-temperature weather characteristics in Guangxi were wide range,long duration and strong extremeness,that was mainly caused by the influence of weather systems such as tropical cyclone,subtropical high and southwest thermal low.The abnormal atmospheric circulation was the main reason for the extreme high temperature.