Abstract:

Based on the data collected from 69 surface observation stations during 1961- 2012 in Jiangsu province，using proper measures to define the concept of haze hours，the temporal and spatial distribution features of severe，moderate，mild and slight haze hours are discussed in the research．According to the characteristics of haze disasters, the administrative regions (districts and counties) are taken as the basic evaluation unit, considering four factors such as the hazard risk, disaster pregnant environment sensitivity, vulnerability and disaster prevention and reduction capacity. This study selects eight factors including the moderate haze hours, severe haze hours, water area, vegetation area, population density, road mileage, public finance expenditure, the number of doctors per million people possessing as the evaluation indexes, uses the analytic hierarchy process to establish a risk assessment model, and with the help of GIS analysis tool, the haze disaster risk regionalization is given. The research shows that the slight haze is the most haze weather in Jiangsu province, with proportion of 77% in all haze weather. The frequency of severe and moderate haze weather is lower, with proportion of 2% and 4% respectively. The trend of annual haze hours of every grade is identical, rising slightly during 1980-2010, and obviously during 2011-2012. The rising trend of slight haze is most obvious, followed by the mild haze. There are common spatial distribution characteristics of all grade haze. West area along the Yangtze River , local area in the north and the southeast of Jiangsu province are the high value area, Nantong is the low value area, and the area facing to the sea and its altitude is low. The natural intensity of haze (the hours of severe and moderate haze) and the risk assessment results of haze disasters are correspondent in the geographical distribution. West area along the Yangtze River and local area in north of Huaibei are the high value areas, showing the correctness and the rationality of the assessment methods. But the haze disaster risk also considered three factors such as disaster pregnant environment sensitivity, vulnerability and disaster prevention and reduction capacity. Thus, the distribution of the result of risk assessment and the natural strength of haze are different. Haze risk level is medium in the area such as the south of the Huaihe, part of Suzhou, Yangzhou, and Zhenjiang because of densely population and developed traffic, although moderate and severe haze hours are less in these area. In northern of Huaibei, some area such as Xinyi, Suqian and other places, the haze risk level is higher, because water and vegetation area is relatively less, disaster prevention and mitigation ability is relatively lower