Statistical Characteristics of the Morphological Parameters of Chinese Cites and the Application in WRF Model

The morphological characteristics of main cities in China were analyzed and the urban morphological parameters were calculated using three-dimensional building data. The calculated parameters (e.g., mean building-height, building plan area fraction, frontal area index) are used to identify similarities and differences of cities in different regions. The method of machine learning is also been employed to derive the universal relationship between urban morphological parameters and Local Climate Zone (LCZ) and the urban morphological parameters database is established using the methodology here. In addition, two sets of numerical simulations (one using the traditional approach of specifying urban parameters through a look-up table in WRF, the other direct-ingesting gridded urban morphological parameters data) were carried out to examine the sensitivity of the performance of the WRF-Chem model to the urban morphological parameters. The simulation results show that the urban morphological parameters could improve the accuracy of the simulation for the pollution events.