1990-2019年我国城市风热环境的演变分析

Analysis of Urban Wind and Heat Environment Changes from 1990 to 2019 in China

近几十年来中国经历了快速城市化,而城市的快速发展也带来了如城市热岛效应等问题,影响了城市居住生活环境的舒适度与城市的可持续发展.本文基于1990-2019年的气象数据、土地利用数据和Landsat遥感影像数据,以中国不同气候区的10个省会城市的城区作为研究对象,对各城市的风热环境与建筑密度的演变进行了分析,得出如下研究结论.(1)研究区城市整体处于升温状态,城市平均风速的变化对城市平均气温的影响有限,背景风环境的变化对城市气温上升的影响不如城市建筑密度的增加;(2)研究区城市热环境的变化与城市建成区的空间扩展和城市建筑密度具有较好的时空一致性,并且城市建筑密度的增加与城市热环境的加剧具有一致的趋势特征,但在不同城市的年际变化上存在较大差异;(3)城市扩张虽然会导致城市高温区的增加,但这并不是导致高温区集中的主要原因,在局地地表覆被类型等地理环境因素的影响下,城市风热环境表现出了不同的地域特征.通过对国内多个城市风热环境的变化与演变趋势进行对比分析,可以为促进城市的可持续发展,制订城市发展的相关决策提供理论和参考依据.

In recent decades,China has experienced rapid urbanization,and the rapid development and expansion of cities have also brought problems such as urban heat island effect,which has directly affected the comfort of urban living environment and the sustainable development.In this study,meteorological data,land use data and Landsat remote sensing image data from 1990 to 2019 were used as data sources,and urban areas of 10provincial capitals in different climatic regions of China were taken as research objects.By analyzing the background wind and heat environment,building density and urban heat environment of each city,the changes of wind and heat environment in the process of urban development were obtained.The results show that:(1)The mainly cities in the study area are in a warming state,and the change of the average wind speed in the city has limited influence on the average air temperature in the city.In addition,the change of urban wind environment has less impact on urban temperature rise than the increase of urban building density;(2)The change of urban thermal environment in the study area has agood temporal and spatial consistency with the spatial expansion of urban built-up areas and urban building density,and the increase of urban building density has a consistent trend with the aggravation of urban thermal environment,but there are great differences in inter-annual changes in different cities;(3)Although urban expansion would lead to the increase of urban high-temperature areas,it is not the main reason for the concentration of hightemperature areas.Under the influence of geographical and environmental factors such as local surface cover types,urban wind-heat environment has shown different regional characteristics.This study compared and analyzed the changes and evolution trends of wind and heat environment in many cities in China,which could provide theoretical basis and reference for promoting the sustainable development of cities and making relevant decisions on urban development.