A Study on Meteorological Effect of the Hangzhou Ventilation Corridors Based on High Resolution Numerical Simulation

Urban ventilation corridors can increase urban air liquidity capacity and relieve the urban heat island. In order to quantitatively evaluate the meteorological effects of urban ventilation corridors, the regional boundary layer chemistry model (RBLM-Chem) was used to analyze meteorological effects of the ventilation corridor under different weather types based on the dataset of high resolution surface types and urban buildings in Hangzhou. The horizontal resolution of the model is 250 m. The results indicate that the urban ventilation corridor can increase wind speed, decrease temperature, and increase humidity. Compared with the situation that the ventilation corridor is absent, wind speeds at the surface and 60-m height in the corridor area increase by 1.4 m/s and 1 m/s, respectively. In the summer, temperature in the corridor area can decrease by 2.7℃ due to the cooling effect of the ventilation corridor. This value is much higher than that in winter, which is only about 0.6℃. At 250-m downstream of the ventilation corridor, the maximum values of the increments of wind speed, temperature, and relative humidity are 1.5 m/s, -2.9℃ and 3.1%, respectively. Even at 1500-m downstream of the ventilation corridor, the maximum temperature increments can still reach up to -1.2℃.