中国台风灾情特征及其灾害客观评估方法

利用上海台风研究所及国家气象中心整编的中国台风灾情资料,分析了中国致灾台风造成的人员伤亡、房屋倒损、农田受淹及直接经济损失等灾情特征.引入了定基物价指数,改进了台风灾害指数(ATDI指数)的计算方法,基于1980-2004年间所有致灾台风的灾害指数的聚类分析,将致灾台风的灾害分为:轻灾(或小灾)、中灾、大灾(或中偏重灾)和重灾4个等级,并据此对1980-2004年间中国致灾台风的灾情进行了客观评估.结果表明:平均每年约有7.2个台风对中国造成明显灾情,最多的年份多达11个、最少年份也有4个.中国致灾台风的频数逐年减少,但造成的灾情却逐年趋重,因台风而伤亡的总人数逐年上升(死亡人数下降)、倒损房屋和受淹的农田面积以及造成的直接经济损失均逐年递增,倒损房屋、受淹的农田面积、直接经济损失的年平均增长率分别为1.33×10~4间/年、2.28×10~4 hm~2/年和14.56亿元/年.1980-2004年间,单个致灾台风而言,倒损房屋、受淹的农田面积、直接经济损失的平均增长率分别为581.4间/个、880.0 hm~2/个和0.33亿元/个.从台风灾害指数看,1990年代中期,中国的台风灾害较为严重,其中1996年最重,而1998年则是1980-2004年间台风灾害最轻的年份.

Characters and objecti ve assessment of disasters caused by typhoons in China.

The characters of casualty, damaged or collapsed house, inundated farmland area, and direct economic loss caused by tropi-cal cyclones (TC) in China during 1980- 2004 are analyzed based on the typhoon disaster loss data compiled by Shanghai Typhoon Institute and National Meteorological Center. Considering direct economic loss and the influence of society development, an Advanced Typhoon Disaster Index (ATDI) for objective assessment of disaster degrees is developed. Based on the ATDIs of all tropical cy-clones, the disasters are divided into four categories: gentle, moderate, heavy, and severe. It is found that on average 7.2 TCs caused remarkable damages in China each year. The annual damage increases with increasing casualty (the death toll dropped dramati-cally), damaged or collapsed house, inundated farmland, and direct economic loss, although the number of TCs causing disasters has dropped in China during 1980 - 2004. The average yearly growth rates of the damaged or collapsed house, inundated farmland, and direct economic loss are 1.33 × 10~3 rooms, 2.28 × 10~4 hm~2, and 1.46 billion RMB, respectively. As far as single TC is concerned, those average growth rates are 581.4 rooms per TC, 880.0 hm~2 per TC and 33 million RMB per TC, respectively. Based on the AT-DI, the damage caused by TCs more severe in the mid 1990's with the severest (gentlest) damage occurring in 1996 (1998) from 1980 to 2004.