郑州市公园绿地景观特征对公园冷岛效应的影响

城市公园有助于缓解城市热岛效应,减少城市降温能耗。选取郑州市中心城区内44个主要公园,利用Landsat8遥感数据和土地利用数据,结合ENVI、ArcGIS、Fragstats、SPSS等软件分析公园冷岛效应的影响因素。冷岛强度的研究从景观特征、景观构成、景观配置3个层面来进行,结果表明:场地条件有限的情况下公园面积控制在20 hm2左右能产生较高冷岛强度;公园边界越简单冷岛效应越强,而植物和不透水表面斑块的边界越复杂公园冷岛效应越强;同等面积下有水体的公园与无水体的公园相比降温效果相差1℃左右;水体占比控制在14%左右公园冷岛强度较为显著;在进行公园景观配置时,公园内植物和水体的组合相比于不透水表面与植物的组合及不透水表面与水体的组合能产生更好的降温效应。利用标准差椭圆工具进一步分析公园冷岛强度的方向性,发现公园的冷岛方向主要与园内水体长轴以及园外高层建筑的分布有关。

The influence of landscape characteristics of a park green space on the park cool island effect in Zhengzhou City

Urban parks can help alleviate the urban heat island effect and reduce urban cooling energy consumption.In this paper,we used Landsat8 remote sensing data and land use data,combined with ENVI,ArcGIS,Fragstats,SPSS,and other software tools to analyze the impact factors of the cool island effect in a selection of 44 major parks from the central city of Zhengzhou City.Studies on the cool island intensity were carried out from three aspects:landscape characteristics,landscape composition,and landscape configuration.Results showed that,under limited site conditions,park areas of approximately 20 hm2 can produce higher cool island intensity than smaller ones;the simpler the boundary of the park,the stronger the cool island effect;and the more complex the boundary between plants and impervious surface patches,the stronger the cool island effect of the park.In the same area,the cooling effect of parks with a water body is approximately 1℃different from that of parks without any water body.The remarkable intensity of cold island was observed in parks where the water bodies represented 14%of the park′s surface.In the park landscape configuration,the combination of plants and water in the park can produce a better cooling effect than the combination of impervious surface and plants or the combination of impervious surface and water.The standard deviation ellipse tool was used for further analyzing the directionality of cool island strength in parks.The conclusion was that the direction of a cool island from a park is mainly related to the direction of the long axis of water bodies present in the park and the distribution of high?rise buildings outside the park.