城市湿地热环境调节功能的定量研究

以Landsat TM和MODIS多源遥感数据反演的城市地表温度和2007年北京湿地普查数据为基础,采用GIS空间分析技术和相关分析方法研究了城市湿地对城市热环境的调节能力并建立了定量模型。结果表明:1)由于湿地景观与城市其他下垫面的性质具有明显差异,湿地分布与城市低温区在空间分布上呈现出非常好的正相关。2)湿地调节指数可以较好地反映城市湿地对城市热环境调节能力的大小。分析其与湿地周长、面积、形状指数和内缘比等单元景观特征指数之间的相关性,发现城市湿地对周边区域的热环境调节能力主要取决于湿地的面积,且可以利用三次多项式来定量描述湿地热调节半径与湿地面积之间的关系。

Quantitative analyses of thermal regulation function of urban wetland

Based on land surface temperatures (LST) retrieved from TM/MODIS satellite images and census data of Beijing wetlands in 2007, the thermal regulation function of urban wetlands was studied, based on a geographic information system (GIS) using a statistical correlation method. The results show that due to the obvious differences of thermal radiation between wetland and other types of terrain, the distribution of wetland and low-temperature regions of urban showed a significant, positive correlation. A Wetland Thermal Index (WTI) is proposed, which reflects the thermal regulation ability of urban wetlands. We found significant correlations between the WTI and unit landscape features, i.e. perimeter, area, shape index and interior-to-edge ratio of urban wetlands, suggesting that wetlands have an important effect on thermal regulation. We developed a cubic polynomial model between WTI and wetland area to describe the relationship between the radius of thermal regulation and the size of urban wetland.