大同市城市化进程对市区气候变化的影响

利用大同市气象站近49年和阳高县气象站近38年逐月气温、风速风向、相对湿度、日照时数、降水量等气象资料，结合大同市1990—2009年城镇人口数和建城区面积的数据资料，对大同市城市化因子气候变化的影响进行分析。结果表明，大同市降水量呈缓慢减少趋势；1972—2000年间，汛期降水量以准3年周期为主，同时存在7年的周期；2000年以后以准7年的周期为主，3年的高频周期基本消失；大同市年平均气温、极端高温、极端低温均呈上升趋势；平均气温略接近热岛状况，20世纪90年代热岛中心强度达到极值；年平均风速、日照时数和相对湿度呈下降趋势；通过计算贡献率可知，城市化因子对气候改变的贡献率相对较大，占影响当地气候变化的37．99％，温度、降水量等气候要素因子占29．73％，其他因子占0．29％～9．26％不等。各气象要素存在明显的Hurst现象，基本保持当前的趋势，但趋势显著性不一。

Influence of Datong City Urbanization on Urban Climate Change

By using of 49 years monthly meteorological data such as temperature, wind speed and direction, relative humidity, sunshine hours, precipitation and so on of Datong Meteorological Station and 38 years monthly meteorological data of Yanggao Meteorological Station, it can obtain the effect of Datong City urbanization on urban climate change with the data of Datong urban population and area from 1990 to 2009. It showed that Datong precipitation decreased slowly, the flood season precipitation was 3 years to the main, and 7 years existed at the same time from 1972 to 2000. After 2000, the flood season precipitation was 7 years to the main, and 3 years disappeared. The annual average temperature, extreme temperature were upward trend in Datong City. The average temperature was close to the heat island conditions, and the intensity of the heat is- land reached maximum in 1990s. Annual average wind speed, sunshine hours, and relative humidity were downward trend. It showed that the ur- ban factor was bigger than other factors by calculating the contribution rate of climate change, the rate was 37.99%, the meteorological factors （such as temperature, precipitation and so on） contribution rate was 29.73%, and other factors were 0.29% to 9.26%. There are Hurst phe- nomenon of every meteorological factor, they all keep the current trends, but these trend significances were different.