Suitability of human settlements in mountainous areas from the perspective of ventilation: A case study of the main urban area of Chongqing

Based on the multi-source data (e.g., building vector and remote sensing data) of the main urban areas of Chongqing, China, this study selected a few natural factors—the relief degree of the land surface (RDLS), land cover index (LCI), annual average land surface temperature (LST), water resource index (WRI), and frontal area index (FAI)—and used the geographic information system spatial analysis method to quantitatively investigate the spatial variation in the suitability of human settlements in mountainous areas from the perspective of ventilation. The study findings can be summarized as follows: 1) The population distribution in the main urban areas of Chongqing is affected by, in descending order, the LCI, FAI, RDLS, WRI, and LST. 2) In the main urban areas of Chongqing, the RDLS ranges from 0.21 to 2.82; it is low in the south and high in the north. The LCI ranges from 0.02 to 0.99; it is relatively low in those urban areas with a high building density. The LST ranges from 15.30 to 24.87 °C; in contrast to the spatial pattern of the LCI, the LST in the urban centers is higher than at the urban peripheries. The WRI ranges from 0.04 to 0.79; it is highest along the Yangtze and Jialing rivers. The FAI ranges from 0 to 1.63, exhibiting a gradual decline from the urban centers to the urban peripheries. As the FAI increases, the ventilation capacity worsens. 3) The ventilation-based human settlements index ranges from 0.06 to 0.54 in the mountainous areas of the city, gradually increasing from the southwest to the northeast in the main urban areas of Chongqing. In addition, zones with unsuitable human settlements are mainly distributed in mountainous regions with a high RDLS and relatively scarce water resources, whereas zones with suitable human settlements are primarily distributed in regions with a moderate RDLS, adequate vegetation cover, appropriate LST, abundant water resources, and adequate ventilation. The study findings can be used to evaluate the comfort level of human settlements, and have strategic significance to the efficient planning of urban development and the optimal layout of the population distribution.