中国城市不透水面空间格局对热岛强度的影响

Impacts of impervious surface spatial patterns on surface heat island intensity in Chinese cities

  • 摘要: 高速城市化带来的不透水面(ISA)扩张成为影响我国城市地表热岛强度(SUHII)的重要驱动因素.辨识不透水面的空间格局对热岛强度的影响仍有待研究.本文利用卫星地表温度(LST)数据和中国 31 个主要城市的高分辨率不透水面数据,全面分析了不透水面的面积、聚集度、斑块密度和边界形状复杂程度,以及人口和NDVI差异对热岛强度的影响.结果显示,我国城市的日间热岛强度存在明显的空间和季节变化,强度由南向北递减,而夜晚则相反.不透水面的面积、聚集度和边界形状复杂程度与热岛强度呈正相关关系,而斑块密度与热岛强度呈负相关关系.通过逐步多元线性回归模型,选取的景观结构、人口及植被变量指标能解释夏季昼夜热岛强度变化的 63.7%、57.0%,以及冬季昼夜热岛强度变化的78.6% 和 39.8%.且不透水面的聚集度与边界形状与白天热岛强度相关性较大,不透水面面积及其聚集程度对夜晚热岛强度有显著影响.研究结果能够为优化城市景观结构和减轻热岛效应对城市安全的影响提供科学参考.

     

    Abstract: Expansion of impervious surface area (ISA) due to rapid urbanization affects crucially the surface urban heat island intensity (SUHII) in China, but spatial patterns of impervious surface area and impact on SUHII remain to be studied. Here in this article satellite Land Surface Temperature (LST) data and high-resolution ISA data from 31 cities in China are used to comprehensively analyze effects of total area, aggregation, patch density and landscape shape of impervious surface, as well as impact of population and NDVI differences on SUHII. Significant spatial and seasonal variations in daytime SUHII are revealed, with decreasing intensity from south to north, but the pattern is exactly the opposite at night. Total area, aggregation, and landscape shape of ISA have a positive correlation with SUHII, but patch density has a negative correlation with SUHII. A stepwise multiple linear regression model reveals that indicators of landscape structure, population, and NDVI can explain 63.7% and 57.0% of changes in summer day and night SUHII, and 78.6% and 39.8% of changes in winter day and night SUHII. The aggregation index and landscape shape index of the ISA are significantly correlated with daytime SUHII, total area index and aggregation index exert significant impact on nighttime SUHII. These data will help to optimize urban landscape structure and reduce impact of heat island effect on urban safety.

     

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