基于GIS对城市热岛效应的探究及驱动因素分析——以大连市中心城区为例

Research on Urban Heat Island Effect Based on GIS and Analysis of Driving Factors—A Case Study of the Central Urban Area of Dalian

摘要: 太阳辐射对城市热环境有重要的影响。下垫面坚硬、建筑密集等特点，使其不仅具有直射和散射的短波辐射，而且还具有强烈的反射和长波辐射。城市辐射场是由各种不同类型的辐射场组成的。城市辐射环境对建筑得、失热量有很大的影响，从而对建筑能耗有很大的影响；另外，它还会对户外环境下的人体热舒适状况有很大的影响。城市辐射是城市环境保护和建筑节能的一个重要课题。本项目拟对城市下垫面对户外辐射和热环境的影响进行系统研究。采用大连市中心城区2013~2022年5期Landsat系列影像，结合地表温度、土地利用分类情况和地理加权回归模型等，探讨影响城市地表温度因素的空间异质性的分析，进而为下一步城市化建设提出有效建议。研究结果表明：① 研究区热环境呈不断上升趋势，由2013年的22.57℃上升至2022年的31.77℃，其中2019~2022年间升温幅度最大；② 研究区的土地利用分类中，建设用地逐年增加，导致城市地表温度始终居高不下而且逐年增长，城市绿地有所改善但并不明显。其对城市地表温度变化的相关性最强；③ LST与其驱动因素的GWR分析结果表明，总体而言，NDVI和和土地利用分类与LST存在明显的空间相关性，即绿色植被越多，地表温度越低；建筑物覆盖程度越高，地表温度越高。而DEM与街道至海岸线的距离与LST的关系存在明显的空间异质性，需要结合其他的因素进一步做出综合考量。

Abstract: Solar radiation has a significant impact on the urban thermal environment. The characteristics of the hard underlying surface and dense buildings not only provide direct and scattered short wave radiation, but also strong reflection and long wave radiation. The urban radiation environment has a significant impact on the heat gain and loss of buildings, thus having a significant impact on building energy consumption; In addition, it also has a significant impact on the thermal comfort of the human body in outdoor environments. Urban radiation is an important issue in urban environmental protection and building energy conservation. This project aims to conduct a systematic study on the impact of urban underlying surfaces on outdoor radiation and thermal environment. Using five Landsat series images in the central urban area of Dalian from 2013 to 2022, combined with the land surface temperature, land use classification and geographical weighted regression model, this paper discusses the analysis of spatial heterogeneity of factors affecting urban surface temperature, and then puts forward effective suggestions for the next step of urbanization. The research results indicate that: ① The thermal environment in the study area is showing a continuous upward trend, rising from 22.57˚C in 2013 to 31.77˚C in 2022, with the largest increase in temperature between 2019 and 2022; ② In the land use classification of the research area, construction land has been increasing year by year, resulting in consistently high and increasing urban surface temperature. Urban green space has improved but is not significant. It has the strongest correlation with changes in urban surface temperature; ③ The GWR analysis results of LST and its driving factors indicate that overall, there is a significant spatial correlation between NDVI and land use classification and LST, that is, the more green vegetation, the lower the surface temperature; The higher the building coverage, the higher the surface temperature. However, the relationship between DEM and the distance from the street to the coastline and LST has obvious spatial heterogeneity, which needs further comprehensive consideration in combination with other factors.