城市热岛与昆明市气候特征变化的关系

Relationship Between Urban Heat Island and Climate Change in Kunming

为了更好地探究城市热岛效应与城市气候特征变化的关系。本文以昆明市为例,利用昆明气象站和呈贡气象站1999—2018年的逐时气象数据,从温度、相对湿度、降水量3个方面定性定量分析了城市热岛与昆明市20年气候特征变化之间的关系。结果表明:(1)由于城镇化进程加快,使昆明市热岛效应增强,引起城市郊区温度升高,热岛范围区向城市郊区扩大,城市高温天数有逐年上升趋势。(2)热岛效应增强会使得相对湿度减小,导致空气变得干燥,给人们带来不舒适感,这点在昆明市冬季尤为明显。(3)热岛效应增强导致城市郊区温度上升,使得郊区温度接近城市中心温度使原来热力环流削弱,冷热空气难以实现交换,阻碍了空气中液滴的形成,进而导致昆明市降水量逐年减少,干旱天气增多,出现大范围旱灾。

In order to better explore the relationship between urban heat island effect and changes in urban climate characteristics.Based on the hourly meteorological data of Kunming and Chenggong meteorological stations from 1999 to 2018,this paper qualitatively and quantitatively analyzed the relationship between urban heat island and climatic characteristics change in Kunming in the past 20 years from three aspects of temperature,relative humidity and precipitation by using the urban-rural dichotomy.The results show that:(1)Due to the acceleration of urbanization,the heat island effect in Kunming is strengthened,and the temperature in the suburbs of Kunming is increased.The area of heat island expands to the suburbs of Kunming,and the number of high temperature days in the city increases year by year.(2)The enhanced heat island effect will reduce the relative humidity,resulting in dry air and uncomfortable feeling for people,which is particularly obvious in the winter of Kunming.(3)The increase of heat island effect leads to the rise of temperature in the suburbs,which makes the temperature in the suburbs close to the temperature in the city center,which weakens the original thermal circulation,makes it difficult to realize the exchange of cold and hot air,and hinders the formation of liquid droplets in the air.As a result,precipitation in Kunming decreases year by year,leading to the increase of dry weather and the occurrence of large-scale drought.