footprint方法在湍流扩散分析中的应用

Application of Footprint Method in Turbulent Diffusion Analysis

引入通量footprint分析方法,结合广西白龙核电厂拟建厂址的湍流实测资料,分析了观测站点不同方向上的通量footprint,并由此确定了水平扩散尺度及水平扩散时间,最终估算了水平扩散参数。与环境评价导则中推荐的扩散时间计算所得的水平扩散参数进行了对比分析。结果表明,离岸流的扩散参数比向岸流大,有利于湍流扩散,从而证明扩散参数具有偏保守性和局地扩散的特性。分析表明,footprint方法在湍流扩散参数分析中具有实际的应用价值。

There are uncertainties in calculating atmospheric diffusion parameters on assessments of the environment. Footprint analysis method is used to confirm the horizontal diffusion scale and time, and finally calculate the horizontal diffusion parameters by using the data measured by the three-dimensional sonic anemometers on the coast of Balong, Guangxi Province. The results show that： 1） diffusion scale and time have obvious influences on determination of diSfusion parameters. 2） The diffusion parameters of the land breeze are larger than that of the sea breeze, which implies that land breeze is in favor of pollution diffusion. 3） The diffusion parameters are conservative and depend on local topography and regional characteristics. Footprint analysis method may be helpful in obtaining diffusion parameters.