A preliminary study on the influence of Beijing urban spatial morphology on near-surface wind speed

Abstract

In order to explore the actual impact of urban spatial morphology on real near-surface wind speed on the urban scale, taking Beijing, China as an example，this study adopted an urban-rural ratio method to construct a WsR (wind speed ratio) to quantify the impact of urbanization on the near-surface wind speed. The spatial morphological parameters such as building height, building density (BD), building standard deviation, floor area ratio(FAR), frontal area index (FAI), roughness length, sky view factor (SVF) and fractal dimension at the 500 m spatial resolution were calculated, and further the relationships of these morphological parameters and WsR was analyzed. Results showed that due to urbanization, the minimum and maximum average annual wind speed of urban areas are 56% and 160% of the suburban wind speed, and urbanization can reduce the wind speed in urban areas at different times by 3% to 27%. On the urban scale, there are significant spatial correlations between the eight morphological parameters and WsR. Except for the quadratic curve of BD and WsR, the other parameters are significantly linearly related to WsR. FAR, FAI and SVF, the three most significant impact factors can individually explain 51%, 48% and 48% of the change of WsR.