基于遥感影像和再分析数据的潜在城市通风廊道研究--以南京市为例

Potential Urban Ventilation Corridors Based on Remote Sensing Imagery and Reanalysis Data:A Case Study on Nanjing City

城市化进程的不断深化导致城市热岛效应加剧,建设大、中型城市通风廊道可有效缓解城市内空气流动困难问题,具有重要意义。基于Python开发语言,解译遥感影像和再分析数据,开发南京市通风廊道算法模型。通过Python与GDAL处理MODIS数据获取南京市地表温度数值,然后调用scipy对频度图进行高斯模糊处理,获取空间分辨率为1 km城市热源和低源的分布;通过Python与xarray处理NCEP再分析资料获取南京市风场,然后调用scipy的线性插值法计算空间分辨率为1 km的南京市风环境。基于两种分布结果,结合江苏省级行政区划矢量数据,以南京市(县)级行政区为基本单元,参考南京市历史城市绿地规划,确定通风走廊走向。最终识别出5条潜在的南京市通风廊道,并给出合理的规划管控建议。

The increasing urbanisation process has led to the intensification of the urban heat island effect and the difficulty of air flow within the city,making it important to strengthen the planning of urban ventilation corridors.This paper is based on the Python development language,interpreting remote sensing images and reanalyzing data to develop an algorithmic model of Nanjing’s ventilation corridors,as follows:Processing MODIS data by Python with GDAL to obtain urban surface temperature values,then calling Scipy to Gaussian fuzzy the frequency map to obtain the distribution of urban heat and low sources at a spatial resolution of 1 km;Processing NCEP reanalysis data through Python with Xarray to obtain urban wind fields,and then invoking Scipy linear interpolation method to calculate urban wind environments with a spatial resolution of 1 km;Based on the results of the two distributions,combined with vector data of provincial administrative divisions,taking county-level administrative divisions as the basic unit and referring to historical urban green space planning,the ventilation corridor alignment was determined.This paper ultimately identifies five potential ventilation corridors and gives sound advice on planning controls.