城市化对上海的增温效应

THE EFFECTS OF THE URBANIZATION ON THE TEMPERATURE INCREASING IN SHANGHAI

上海城市热岛效应很强， 并对气温增暖产生影响。利用主成份分析法从上海及其从近到远的４ 个郊县的２９ 年月平均温度资料中，提炼出影响上海气温变暖的两个主要因子：城市化影响和区域气候变化， 并从而推算出２９ 年来城市化使上海年平均温度增加约０．２０℃， 若排除郊区城镇化因子的影响后， 该值将更高一些。

Urban heat island may result in the major systematic error during temperature observation Shanghai is the biggest city in our country and develops rapidly Several indexes in 1990 are several times higher than in 1962 such as GDP, population density, city scale and energy consumption So, there are strong heat island effects This paper deals with the monthly mean temperature data during 1960-1988 in Shanghai and its four suburban counties stations by using the principle component analysis The results show: (1) At each station, the maximum of the first eigen vector and the mean value (5 years) of the first principle component (PC1) have a tendency of decreasing with the distance increasing to urban area It indicates that the urban heat island effect is stronger in urban area than in suburban area The annual tendency rate of the first eigen vector is larger in urban area than in suburban area, which shows heat island develops faster in urban area than in suburban area (2) The second eigen vector at each station is negative in summer and positive in winter, which reflects that it is cool in summer and warm in winter in Shanghai The second principle component (PC2) reflects that the annual mean temperature has an about 16 year periodical vibration All of the annual tendency rates of PC2 are positive, which indicates a tendency of temperature increasing The conclusion is drawn out from what discussed above that the temperature in Shanghai has risen 0 20℃ during 29 years due to the urbanization It is estimated that this value would be higher excluding the effect of the urbanization factor of the suburban counties