长江三角洲气温变化特征及城市化影响

Temperature change characteristics and its influence by urbanization in the Yangtze River Delta

基于长江三角洲国家基本/基准站历史气象资料和区域人口资料,分析了1959～2005年和1981～2005年期间长江三角洲气温的年和季节变化特征,气温变化在大城市、中等城市和小城镇站之间的差异,以及城市化效应对气温的增温率和增温贡献率。结果表明,过去47年和25年期间,长江三角洲年均气温、年均最高和最低气温都显著增加,增温率都是冬季和春季较高,夏季最低。大城市站增温率明显高于小城镇和中等城市站,城市化效应对大城市气温基本上都是增温作用,其中对平均最低气温的增温率及贡献率最大,对平均最高气温都最小。长江三角洲气温变化趋势和增温率、城市化效应的增温率及增温贡献率与其他地区具有较好的一致性。

With global climate change and rapid regional urbanization, temperature and ecoenvironment changed significantly in the Yangtze River Delta. Based on regional meteorological data from basic/reference climatological surface stations and population data, annual and seasonal temperature change characteristics, the difference of temperature change in big cities, middle cities and small towns, and the urbanization warming and its relative contribution to the total amounts of temperature change was analyzed covering the periods from 1959 to 2005 and from 1981 to 2005. The result indicates that in the past 47 years and 25 years, annual mean temperature, annual mean maximum and minimum temperature increased significantly, with the highest warming rate in winter and spring, and the lowest warming rate in summer. For all types of stations, the annual and seasonal mean temperature, mean maximum and minimum temperature generally increased in the two periods of time. The warming rate in big cities was significantly higher than that in middle cities and small towns, and urbanization warming was almost in annual and seasonal temperature in big cities. The warming rate of urbanization and its relative contribution to the total amounts of temperature change was highest in mean minimum temperature, and lowest in mean maximum temperature. From 1959 to 2005, the warming rate in small towns was close to that in middle cities, and the influence of urbanization on the temperature in middle cities was small, but from 1981 to 2005, the warming rate in middle cities was higher than that in small towns, and the warming rate of urbanization for middle cities was significant. In the Yangtze River Delta, the changing trend and warming rate of temperature, the warming rate of urbanization and its relative contribution to the total amounts of tem- perature change were basically consistent with that in other places. Causes for the differences between our result and those found by other researchers are likely to be related to regional extent, the criteria for defining urban and contrasting stations, the different influence of urbanization on the contrasting stations, station network density, analytical methods, time periods, and etc.