基于多源卫星资料的太原市城市热岛效应分析

Analysis of Urban Heat Island Effect in Taiyuan Based on Multi Source Satellite Data

随着太原市建成区面积不断扩大,人口数量不断增加,人为活动以及下垫面的变化会影响太原市地表温度的时空分布,城市热岛现象也随之发生变化。为了对太原市今后城市发展及生态文明建设提供科学依据,利用Aqua/MODIS、数字高程、土地利用分类、城市灯光等多源卫星资料计算太原市2003—2019年城市热岛强度和城市热岛比例指数,分析太原市城市热岛效应时空变化特征,并结合高空间分辨率的Landsat8数据分析太原市热岛区和冷岛区下垫面特征。结果表明:2003—2019年,太原市辖区各县(市、区)城市热岛效应较强的月份主要发生在7—9月,且多在8月城市热岛效应最强,辖区各县(市、区)中小店区城市热岛效应最强;近20年来,太原市辖区各县(市、区)城市热岛强度变化趋势不同,南部的小店区、晋源区和清徐县城市热岛强度整体增加趋势明显且逐渐相连成片,在今后城市发展中应重点关注,北部、东北部和西南部郊区的强冷岛区域的面积增加显著,有效缓解了所在县(市、区)的热岛强度;在城市发展建设中,注意金属、混凝土或塑胶等建筑吸热材料对局部热岛效应的加强作用,可通过大面积水体、植被等缓解局部地区热岛效应。

With the continuous expansion of built-up area and population in Taiyuan City,and the population is increasing.The changes of human activities and underlying surface affect the temporal and spatial distribution of surface temperature in Taiyuan City,and the phenomenon of urban heat island changes accordingly.In order to provide scientific basis for the future urban development and ecological civilization construction of Taiyuan City,the urban heat island intensity and urban heat island proportion index of Taiyuan city from 2003 to 2019 were calculated by using multi-source satellite data such as Aqua/MODIS,digital elevation,land use classification and urban lighting and so on.Then the spatial and temporal variation characteristics of urban heat island effect in Taiyuan City were analyzed.And combined with high spatial resolution Landsat8 data,the characteristics of underlying surface in heat island and cold island areas of Taiyuan City were analyzed.Results show that the strong urban heat island mainly occurs from July to September and the strongest urban heat island mostly occurs in August from 2003 to 2019.The region with the strongest urban heat island effect is located in Xiaodian.In recent 20 years,the trend of urban heat island intensity in counties of Taiyuan City is different.The overall increase trend of urban heat island intensity is obvious in Xiaodian,Jinyuan and Qingxu in the south of Taiyuan City,should be focused in the future urban development.The area of strong cold islands in the northern,northeastern and southwestern suburbs increase significantly,which effectively alleviate the intensity of heat island.During urban development and construction,building heat absorbing materials such as metal,concrete or plastic can enhance local heat island effect and large area of water and vegetation can alleviate heat island effect in local area.