成都市热岛效应特征分析
Characteristics Analysis of Heat Island Effect in Chengdu

为探讨成都市2007~2022近15年来热岛效应特征和时空演变规律，基于四年(2007、2012、2017、2022年)的MODIS遥感影像反演了成都市地表温度，结果表明：1) 成都市地表温度总体呈现上升趋势，呈现以中心城区为热中心，向城区周围扩散的分布特征，昼夜季节变化显著。年均地表温度低于10℃的地区基本位于西北地区，而日间年均地表温度28℃以上的地区主要位于中部地区；2) 从季节上看，热岛效应呈现夏强冬弱的特征，其中夏季城区和郊区平均温度差值可达6℃。春季、夏季夜间和秋季夜间热岛强度有增强趋势；3) 成都市城区内热岛状况有所改善，但周围受热岛效应影响范围扩大，热岛面积扩张；4) 成都市日间地表温度在城区的四周区域显著下降；西部山区地表温度变化与山地城市分布有关；成都东部以龙泉山脉为界温度变化多为带状分布。夜间地表温度变化多呈未显著变化。
To investigate the characteristics and spatiotemporal evolution of the urban heat island effect in Chengdu over the past 15 years (2007~2022), MODIS remote sensing images from four years (2007, 2012, 2017, and 2022) were used to retrieve the land surface temperature of Chengdu. The results indicate that: 1) The land surface temperature in Chengdu has generally shown an upward trend, with a distribution pattern characterized by a heat center in the central urban area spreading towards the surrounding urban areas. There are significant diurnal and seasonal variations. Regions with an annual average land surface temperature below 10？C are mainly located in the northwest, while areas with a daytime annual average land surface temperature above 28？C are primarily located in the central region; 2) Seasonally, the heat island effect is stronger in summer and weaker in winter, with the temperature difference between urban and suburban areas reaching up to 6？C in summer. The intensity of the heat island effect at night during spring, summer, and autumn shows a trend of increasing; 3) The heat island situation within the urban area of Chengdu has improved, but the area affected by the heat island effect around the city has expanded, with the heat island area increasing; 4) During the daytime in Chengdu, surface temperatures significantly decrease in the surrounding areas of the urban district. In the western mountainous regions, surface temperature changes are associated with the distribution of mountainous cities. To the east of Chengdu, temperature variations along the Longquan Mountains are typically distributed in bands. Nighttime surface temperature changes generally show no significant variation.