减弱热岛强度的城市形态布局关键参数与响应机制

基于天津市1992—2013年7景夏季TM遥感影像,分别提取城市形态与反演城市热岛强度,利用ArcGIS与MATLAB等大数据分析计算软件,定量研究城市形态布局与热岛强度的响应机制与参数曲线,提出了热岛强度双指标测度的概念算法,即最高热岛升温和热岛升温总量。结果表明:热岛强度随着城市形态面积的增大而上升,总体上城市形态总面积与最高热岛升温、热岛升温总量都呈线性关系;城市形态离散度和临近度,与最高热岛升温不存在明显相关性,而与热岛升温总量呈线性关系;斑块面积与热岛强度呈正相关,50km2以上的斑块,面积与最高热岛升温呈线性关系,与热岛升温总量呈二次曲线关系;周长面积比与热岛强度呈负相关,与最高热岛升温成S曲线关系,当介于0.005,0.04]时则与最高热岛升温呈四次曲线关系;斑块分维数与热岛强度呈正相关关系,与最高热岛升温呈线性关系,与热岛升温总量呈三次曲线关系。

Key Parameters in Urban Form Layout for Weakening Urban Heat Island Intensity and Its Response Mechanism

The relationship between urban form layout and Urban Heat Island (UHI) intensity response mechanism was quantified and the parameter curves was studied. Large-scale analysis and calculation software such as ArcGIS and MATLAB are used and extract Urban Form and inversed UHI, based on the seven times summer TM images of Tianjin between 1992 and 2013. The results show that: Firstly, the double indicators measure for the UHI intensity was proposed, that is, highest UHI temperature value and total UHI warming. Secondly, the UHI intensity increases with the expansion of urban form area; and in general, gross area of urban form is positively correlated with highest UHI temperature value and total UHI warming.Thirdly, dispersion of the urban form and contagion index are not apparently involved with highest UHI temperature, but correlated with total UHI warming.Fourthly, plague area has a positive relationship with UHI intensity; with a single plague over 50 km 2, highest UHI temperature value will grow rapidly by the linear along with the increase of plague and a quadric curve correlation between plague area and total UHI warming is obtained. Fifthly, there was a negative relationship between perimeter-to-area ratio of the plaque and UHI intensity and a S curve correlation between perimeter-to-area ratio of the plaque and highest UHI temperature value. When the ratio is between 0.005 to 0.04, a quadric curve correlation will be formed between perimeter-to-area ratio and highest UHI temperature value. Finally, urban form fractal dimension is positively relevant with UHI intensity and in a linear relationship with highest UHI temperature and a cubic curve relationship with Total UHI warming.