城市非均匀性对城市气象特征影响的数值模拟

Numerical Simulation of Urban Heterogeneity's Influence on Urban Meteorological Characteristic

为了研究城市的非均匀性对城市气象特征的影响,根据南京市建筑密度分布特征,将南京市不同区域的城市分为商业型城市、高密度城市和低密度城市。利用WRF模拟研究南京地区城市类型的非均匀分布对城市气象特征的影响。结果表明,考虑城市的非均匀性之后,城市区域气温、热岛、相对湿度和风场表现出更加复杂的空间分布。在城市冠层的模拟中,均一或非均一城市类型对城市热岛等城市气象特征影响显著。模拟的城市平均热岛强度、平均干岛强度和平均风速衰减分别减小0.02℃、0.2%和0.11 m·s-1,但城市的最大城市热岛强度、最大干岛强度分别增加0.28℃和1.51%。非均一城市类型中的城市热岛、干岛和风速衰减的空间分布的方差分别增加0.06,2.08和0.28。

The Nanjing city was divided into three types according the building density : Commercial,Hi-dens Res( High intensity residential),Low-dens Res( Lowintensity residential). The influence of urban heterogeneity on urban meteorological characteristic in Nanjing was researched by WRF model. The results showthat: After considering the effect of the urban heterogeneity,the spatial distribution of temperature,the urban heat island,the relative humidity and the winds exhibit are more complex in the urban region. In the simulations of urban canopy,urban heterogeneity has obvious effects on the heat island and other meteorological characters. The simulated mean heat island intensity,dry island intensity and decrease of wind of city will decrease 0. 02℃,0. 2%and 0. 11 m ·s-1. But the maximum heat island intensity and dry island intensity of city will increase 0. 28℃and 1. 51%. In the city of considering heterogeneity,the spaial distribution variances of urban heat island,dry island and decrease of wind will increase 0. 06,2. 08 and 0. 28.