宜春地区主要气象灾害分布规律及成因分析

CHARACTERISTICS OF DISTRIBUTION AND CAUSE OF THE MAJOR WEATHER DISASTERS IN YICHUN REGION

利用1959—2008年气象观测资料和1949—2008年气象灾情资料,对发生在宜春地区的暴雨和洪涝、大风、冰雹、干旱、高温、低温和冷冻、雷电等7类主要气象灾害的分布规律及成因进行了分类分析。结果表明,宜春地区每年都会出现不同程度的洪涝灾害,重度洪涝灾害为3—5 a一遇。东部和西部各有1个大风多发区;大风7—8月最多,12月最少。冰雹平均每年出现2.5站次。伏旱、秋旱平均每年出现1次以上。≥35℃的高温天气出现在3—10月,主要在7—8月;≥37℃的高温天气出现在5—9月,主要在7—8月。<0℃气温主要出现在1—3月和11—12月,1月最多;<-5℃气温出现在1—2月和12月,1月最多。春季低温出现次数以西部和北部为多;轻度寒露风出现日期平均为9月9日—10月20日,重度寒露风出现日期平均为9月26日—10月10日。雨淞主要出现在1—2月和12月,1月最多;地面结冰主要出现在1—3月和11—12月,1月最多。雷暴8月出现最多,其次是7月、6月、4月和5月,12月最少,白天多晚上少;西部多于东部,丘陵山区多于平原。

Based on 1959—2008 meteorological data and 1949—2008 meteorological disaster information,characteristics of distribution and cause of seven major weather disasters in Yichun region are analyzed.The results show that almost every year the flood occurs in Yichun,severe floods occur every 3—5 years.There are strong wind centers in eastern and western region of Yichun respectively.Most of the strong wind occurs in July—August,and least in December.Averagely,hail appears 2.5 times per year,summer drought and autumn drought happen 1 time per year.High temperature weather often occurs in March—October,mainly in July to August.Those with the temperature higher than 37 ℃ generally appear in May—September,mainly in July—August.During January—March and November—December,the air temperature always reaches lower than 0 ℃,especially in January.And during January—February and December,the air temperature can reach lower than-5 ℃.Spring low temperature appears mostly in the west and north region of Yichun.The average date of slight cold dew wind appearance is September 9-October 20,and that of severe cold dew wind appearance is September 26—October 10.Glazed frost mainly appears in January—February and December;ground ice can be seen in the January—March and November—December.Thunderstorms occur mostly in August,followed by July and June,and least thunderstorms appear in April,May and December,which mainly happen in daytime.