杭州湾地区核电厂大气中尺度扩散特征研究

Characteristics of meso-scale atmospheric diffusion over Hangzhou Bay area from a nuclear power plant address

采用拉格朗日随机粒子扩散模式和当地实际气象资料,模拟以秦山核电厂为排放源的大气污染物在杭州湾地区的中尺度扩散情况.对代表性年份(1996)各季中月整4个月模拟结果的分析表明,各季平均扩散输送特征受季节变化和当地海陆地形分布的影响明显.春夏季(4,7月)以溯杭州湾往偏西和偏北内陆方向的输送为主,冬秋季(1,10月)主要为向杭州湾南岸及外海诸方向的输送.区域平均扩散能力以春季(4月)为强,秋季(10月)较弱.污染物扩散输送出模拟区域的平均时间春季略小于15h,秋季约24h,冬夏季约20h.

A Lagrangian stochastic model and practical meteorological data are employed to study the characteristics of mesoscale atmospheric diffusion over Hangzhou Bay area, Zhejiang province, with the emission source at Qinshan nuclear power plant location. Four months in representative of 4 seasons in a year (1996) are simulated and statistical results from hourly data in each month are presented. Average patterns of atmospheric diffusion showed evident seasonal characteristics and variation, as well as the influence of landsea terrain distribution on transport paths. There are approximately westerly transport patterns upstream in the Hangzhou Bay river for spring and summer (April and July). While transport across the Hangzhou Bay to south bank and east sea surface are essential for autumn and winter (October and January). The atmospheric dilution ability over this region is the strongest in spring, and the weakest in autumn. The average time scales for airborne material transport out of the region are approximately 15 hours and 24 hours for spring and autumn, respectively. While that time scale is about 20 hours for winter and summer.