上海地区台风灾害损失评估

LOSSES ASSESSMENT OF TYPHOON DISASTER IN SHANGHAI DURING 1949-2009

台风是一种生成于热带或副热带洋面上的破坏性很强的天气系统。历史上台风对上海曾造成较大的影响和经济损失。利用上海气象站风、雨观测资料、上海基础地理信息数据、上海社会和经济数据以及台风灾情资料,利用逐步回归方法建立了上海台风灾害损失评估模型,并开展了上海台风灾损的年际变化和地区分布差异评价。结果表明建立的台风灾害损失评估模型可以用来进行台风灾损评估。近50a来上海台风灾损度的变化趋势不明显,上海地区因台风影响造成的损失以沿海的崇明、南汇最严重,其次是地势低洼的青浦、金山和松江,中心城区和闵行台风灾损最低。由于历史台风灾情资料记载的不完整性和本评估未充分考虑上海社会经济发展及自然灾害防御能力的提高对台风灾损的影响,评估结果还具有一定的不确定性。深入综合考虑台风灾害致灾性和当地社会经济发展变化,建立更科学的台风灾害损失评估模型,是今后的研究方向。

Natural disaster is one of the most important global issues we are facing. Typhoons bring about gales,rainstorms, very rough seas and storm surges, do great damage to the community, and cause loss of human life and destruction of properties. Greenhouse gas-induced climate warming potentially could affect tropical cyclones in a number of ways, including intensity, frequency of occurrence, geographical distribution,and storm tracks. The combined influence of increasing sea-level rise and stronger tropical cyclone could result in flooding in coastal area. As one of the most dangerous weather systems with the maximum wind of 34 knots or higher,typhoon has caused enormous losses of life and economic damage in Shanghai. There were totally 145 affecting typhoons in Shanghai during 1949--2009 ,of which there were 117 affecting typhoons during 1961--2009,with mean annual of 2.4 affecting typhoons. The frequency of affecting typhoons varied greatly between years in Shanghai, depending mainly upon the atmospheric circulation background. The impact of typhoon could be worse by population increases and higher density, more people living near the coast, greater wealth, and other factors, so quantitative losses assessment of typhoon disasters in Shanghai is important for disaster prevention and mitigation. Based on the wind and rain observations from 11 meteorological stations, basic geographic information data, social economic statistic data and historic typhoon loss data,three kinds of disaster,i, e. casualties,inundated cropland area and collapsed or damaged houses were collected, and the damage indices were calculated from 41 typhoons. The correlation coefficients between damage indices and disaster-causing factors were calculated, and the step-wise regression method was used to establish loss evaluation model of typhoon disaster for Shanghai. The inter-annual variation and regional distribution difference of typhoon disaster losses was also assessed in Shanghai during 1949--2009. The results indicated that there was a significantly positive correlation between the damage index of disastrous typhoon and the mean maximum wind speed in 10min at 10m height and total precipitation. The loss evaluation model was effective and modeled results were suitable for losses assessment of typhoon disaster in Shanghai. During 1949--2009, the inter-annual variation of typhoon disaster losses was not obvious,with higher damage indices during 1961--1970 and 2001--2009, and lower damage indices during 1971--1980 and 1991--2000. Spatially, the typhoon disaster losses were more serious in coastal areas such as Chongming and Nanhui and in low-lying areas such as Qingpu,Jinshan and Songjiang. In urban areas and Minhang,the disaster losses were the least. Thus,regions with higher typhoon disaster losses should be taken as the core areas for disaster prevention and counteraction in Shanghai. With rapid industrialization and urbanization, Shanghai had obvious growth in population and the values of property,and has become more vulnerable to typhoon disaster. But due to the rapid economic development and increased natural disaster prevention and mitigation efforts by the local government in recent years,the typhoon disaster losses changed little or somewhat decreased. So it is necessary to build a comprehensive loss evaluation model of typhoon disaster furtherly with the impacts of natural and social factors considered.