近25 a银川市城市化进程中热力景观格局演变分析

Evolution of Thermal Landscape Pattern in Urbanization of Yinchuan City in Recent 25 Years

以西北地区快速城市化进程中的银川市为例,定量分析城市化水平,划分城市化的不同阶段;基于Landsat影像反演地表温度,划分热力景观类型,从景观和斑块尺度对不同阶段的热力景观组成、形态和异质性进行分析,研究不同土地利用类型对热环境的贡献度。结果表明:银川市存在明显的热岛效应,热岛分布与建成区和裸地分布基本一致,从市中心到城郊呈现明显的温度下行趋势;不同土地利用类型的温度场具有明显差异,平均温度排序为:裸地>建设用地>绿地>水体;不同城市化阶段中土地利用类型的热贡献度不同,土地利用格局影响城市热环境,绿地和裸地的空间分布对地表温度的影响更大。

Based on the Landsat images and statistical data,in this paper the urbanization process and thermal landscape dynamics of Yinchuan City were analyzed. The objectives of this study were as follows： 1 To analyze the spatial and dynamic characteristics of urban thermal landscapes based on the landscape pattern index; 2 To assess the influence of the urbanization process on the thermal landscapes; 3 To understand the relationship between the land use pattern and the land surface temperature（ LST） based on the distribution index. The results showed that there was a significant heat-island effect in Yinchuan City,and the high temperature area was consistent with the built-up area and the unused land. LST declined from the downtown to the suburbs,and an obvious difference of the dynamic characters of the thermal landscapes could be identified at the different stages of urbanization. LST for various land use had obvious discrepancies,the mean LST for the land use types was in a descending order of unused land,construction land,green land and water body. Different land use types had different thermal distribution at different stages of urbanization. The land use pattern influenced the urban thermal environment,especially the spatial distribution of green land and unused land affected LST more significantly.