川南城市群热岛效应对臭氧污染的影响

The Impact of Heat Island Effect on Ozone Pollution in Southern Sichuan Urban Agglomeration

摘要: 由于城市化进程快速推进，城市环境问题日益凸显，热岛效应和臭氧问题是城市化两个突出的环境问题。为了研究川南城市群热岛效应对臭氧浓度的影响，本文用MODIS地表温度数据以及臭氧历史监测数据，分析了2010~2019年川南城市群城市热岛效应和臭氧浓度的时空分布特征、热岛效应对臭氧浓度的影响。结果表明：(1) 川南城市群城市用地热岛强度的年变化波动幅度较大，总体表现为2015年前减弱，2015年后增强，其中热岛强度最高值出现在2012年(1.39℃)，最低值出现在2015年(−0.23℃)。热岛强度季节变化幅度较大。从空间分布上看，川南城市群秋季强热岛分布面积最广，冬季热岛分布显著缩减；(2) 川南城市群五个城市臭氧浓度均呈现春夏高，秋冬低的分布特征，五个城市除乐山外其余四个城市夏季臭氧浓度约为冬季的两倍。空间分布上，春季和冬季臭氧浓度空间分布表现为内江和自贡略高于剩余三个城市，夏季乐山和内江出现大面积高值区(88~102 μg/m³)；(3) 热岛强度与臭氧浓度存在显著正相关性。城市化发展程度越高，对土地覆盖的影响越大，人口密度越集中，热岛效应越明显，促进臭氧的生成。

Abstract: Due to the rapid progress of urbanization, urban environmental problems are becoming increasingly prominent, with heat island effect and ozone problem being the two prominent environmental problems of urbanization. In order to study the impact of urban heat island effect on ozone concentration in the southern Sichuan urban agglomeration, this paper uses MODIS surface temperature data and historical ozone monitoring data to analyze the spatiotemporal distribution characteristics of urban heat island effect and ozone concentration in the southern Sichuan urban agglomeration from 2010 to 2019, as well as the impact of heat island effect on ozone concentration. The results show that: (1) the annual fluctuation of urban land heat island intensity in the southern Sichuan urban agglomeration is significant, with an overall trend of weakening before 2015 and increasing after 2015; The highest value of heat island intensity occurred in 2012 (1.39˚C), and the lowest value occurred in 2015 (−0.23˚C). The seasonal variation in heat island intensity is significant. From a spatial distribution perspective, the autumn heat island distribution area in the southern Sichuan urban agglomeration is the widest, while the winter heat island distribution is significantly reduced; (2) The ozone concentration in the five cities of the southern Sichuan urban agglomeration shows a distribution pattern of high in spring and summer, and low in autumn and winter. Except for Leshan, the ozone concentration in the other four cities in summer is about twice that in winter. In terms of spatial distribution, the spatial distribution of ozone concentration in spring and winter shows that Neijiang and Zigong are slightly higher than the remaining three cities, while in summer, Leshan and Neijiang have a large area of high-value areas (88~102 μg/m³); (3) There is a significant positive correlation between heat island intensity and ozone concentration. The higher the level of urbanization development, the greater the impact on land cover, the more concentrated the population density, the more obvious the heat island effect, and the promotion of ozone generation.