华南地区城市化对区域气候变化的影响

按照人口数将华南地区站点分为大城市站、一般城市站、郊区站,并利用华南地区1960~2011年的站点观测资料分别计算了3类站点年平均、季节平均的气温、高温日数、降水、相对湿度、风速、日照时数距平序列的变化,分析了城市化对华南地区区域气候的影响。结果表明:相较于背景场,大城市的平均气温有更明显的上升趋势;高温日数在3类站点中均有增加的趋势,在城市化的影响下,大城市的高温日数有明显的增加;平均气温日较差在整个华南地区均有下降趋势,特别是在大城市中。在3类站点中,降雨总量均有减少的趋势,且降雨更多的以中雨及以上的形式表现。该地区的相对湿度、风速、日照时数均呈现减少趋势,在城市化影响下,大城市的相对湿度、风速、日照时数均有明显的减少。华南地区处于我国最大的城市群之一——珠江三角洲地区,同时处于气候系统复杂的热带季风区,因此有必要研究城市化对该地区多个气象变量的可能影响。

Urbanization Effects on Local Climate Change in South China

According to the population data of South China, the meteorological stations in this region were divided into three categories: Big city stations, city stations, and suburban stations. Then, using the observational data collected at these stations during the period 1960-2011, we calculated the annual and seasonal average data, and obtained time series of anomaly data for temperature, high temperature days, precipitation, relative humidity, wind speed, and sunshine duration. The results showed the average temperatures of the big cities to have increasing trends in comparison with the background field. Furthermore, the frequency of annual high temperature days became higher, while the range of average temperature revealed a downward trend, especially in big cities. Precipitation amounts throughout the whole area declined, particularly with respect to light rain. Relative humidity, wind speed, and sunshine duration revealed a decreasing trend; moreover, under the influence of urbanization, the relative humidity, wind speed, and sunshine duration of big cities decreased significantly. South China lies in the largest urban agglomeration of China, while also being situated in the tropical monsoon area, where a complex climate system exists. Therefore, it is necessary to study the influence of urbanization in this area from the perspective of multiple variables.