冬季城市湿环境测试研究

Survey study of city humid environment in winter

为了掌握城市冬季空间湿环境分布特征，在冬季晴朗微风的天气条件下，以汽车流动观察法，用自记式温／湿度计分别在昼间和夜间测试了西安城区280个点的温度和相对湿度值，对测试数据进行时间修正后，绘制出城区等湿度线．分析调查结果后发现：西安冬季存在弱“干岛”效应，昼间的干岛强度约为0．3（g／kg·干空气），夜间则为0．4～0．5（g／kg·干空气）；受下垫面性质影响，空气含湿量在空间分布上存在南郊大于城市中心和北郊；但在时间分布上没有出现明显的“干岛”和“湿岛”昼夜交替现象．受城市“热岛”造成的城市空气温度分布影响，空气相对湿度具有明显的由市区向郊外逐渐增大的趋势．

To find out characters of city humid environment distribution in winter, in terms of ＂moving automobile investigating method＂, temperature and relative humidity data of 280 locations in Xi＇an city were collected by automatic data recording device in daytime and night time on Feb. 7th 2006 and in night time on Feb. 20th respectively under clearness and less cloudy weather. The humidity ratio of each location was calculated corresponding to data 0f temperature and relative humidity after corrected them to be synchronous. The results show that humidity ratio in south suburb is higher than that in urban centre and north suburb in winter in Xi＇an city. Urban dry island intensity is about 0.3 （g/kg. dry air） in daytime and 0.4-0. 5（g/kg. dry air） in night time; influenced by urban heat island. The relative humidity increases from urban centre to suburbs gradually, the differen of relative humidity between urban centre and suburb was about 10%RH and 20%RH in daytime and night time respectively.