基于遥感和数值模拟的重庆海绵城市热岛效应分析

Evaluation of the Urban Heat Island Effect of Sponge City in Chongqing using Satellite Remote Sensing Data and Numerical Simulation

为探索海绵城市规划对城市热岛效应的减缓作用,利用MODIS地表温度资料,使用考虑了复杂地形环境的城市聚类法构建热岛强度指数,对比分析采用海绵城市规划的新城区与无海绵城市规划的老城区以及无海绵城市规划的新城区间的热岛强度时空变化差异;同时,进一步通过多尺度数值模拟进行了海绵城市规划、传统城市规划和在传统规划基础上单纯增加平均绿化率等三种土地利用规划方案的敏感性试验。结果表明,采用海绵城市规划的新城区其热岛效应主要来自周边城市的热岛辐射,且相对于传统城市,其平均热岛强度更小、强热岛增长趋势相对缓和。数值模拟试验表明,海绵城市通过更合理的土地利用空间布局,相比另外两种规划方案较好地降低了近地面气温并改善了局地通风环境,最终起到减缓热岛效应的作用。

To evaluate the influence of sponge city planning on urban heat island effect,space-time characteristics of an urban heat island index,which defined by a complex terrain considered City Cluster Algorithm and calculated using land surface temperature data from MODIS satellite remote sensing,of a constructing urban area with sponge city planning in Chongqing,China has been compared to constructing and constructed urban areas with traditional city planning.Meanwhile,sensitive tests of different land use planning have also been implemented using multi-scale numerical simulation.The analysis results show that the heat island effect in new urban areas with sponge city planning mainly comes from the heat island radiation of the surrounding cities,and compared to traditional cities,the average heat island intensity is smaller and the trend of strong heat island growing is relatively moderate.Results of the numerical simulation indicate that sponge city can has lower near-surface temperature and better ventilation by using more reasonable land use planning,which ultimately appears as a reduction of urban heat island effect.