This study was conducted in the context of the latest Chinese policy on “double carbon”. First, we obtained building skywell and meteorological data parameters through a site survey and measurements. We applied the PHOENICS software to simulate and analyze the wind environment of a traditional building skywell. Secondly, the outdoor wind environment of typical building skywells could be simulated and evaluated one by one. Finally, using the method of controlling the variables and by combining typical buildings and skywell-scale layouts, the study summarized and compared the wind environment of the skywell under different scale combinations from three aspects: building skywell shape, skywell scale ratio, and skywell door opening. The following conclusions were drawn: (1) Among the four skywell shapes, the wind environment inside of the skywell was best in the HUI shape. (2) The wind environment inside of the skywell was best in the simulated skywell width-to-height ratio D/H values of 0.2–0.6; the AO shape D/H value was equal to 0.3; and the best wind environment in the skywell occurred when the D/H value of the HUI shape was equal to 0.4. (3) The wind environment in the skywell was best in the range of 1–1.5 for the aspect ratio W/L in the HUI-shaped building skywell (when the width-to-height D/H ratio was 0.4). (4) The opening of the door of the residential building had a great impact on the wind environment of the skywell.

Resource-exhausted cities usually face problems of environmental degradation, landscape fragmentation, and impeded ecological mobility. By clarifying the spatial heterogeneity of ecological restoration needs, efficient and coordinated ecological protection and restoration can be carried out. This study selected Jiawang District, a typical resource-exhausted city, and constructed an ecological security evaluation framework to determine the ecological source area from the three aspects of ecosystem service importance, ecological sensitivity, and landscape stability. The resistance surface was corrected with ecological sensitivity evaluation data, and ecological corridors and ecological nodes were identified using circuit theory. Finally, it explored the spatial and temporal evolution of the key areas of territorial ecological restoration in Jiawang District. This study indicates that: (1) In 2000, 2010, and 2020, the ecological source areas were 123.59 km², 116.18 km², and 125.25 km², and the corresponding numbers of ecological corridors were 53, 51, and 49. The total lengths of the ecological corridors were 129.25 km, 118.57 km, and 112.25 km, mainly distributed in the northern and central areas of the study area. (2) The study area contained 17, 13, and 19 ecological pinch points in 2000, 2010, and 2020, respectively, 16, 20, and 15 ecological obstacle points, and 8, 24, and 33 ecological fracture points, respectively. Targeted rehabilitation of these key areas can significantly improve ecological connectivity. (3) The key area of territorial ecological restoration in 2020 was composed of 125.25 km² ecological source area, 8.77 km² of ecological pinch point, 12.70 km² of ecological obstacle point, and 33 ecological fracture points. According to the present situation of land use, protection strategies are put forward.

The over-exploitation and utilization of natural resources in mining cities has caused sharp contradictions between urban development and ecological protection. In addition, dynamic changes in resources and environmental carrying capacity (RECC) will be changed by the different ways and degrees of the specific utilization of natural resources. In order to better study the dynamic trends and reasons of the RECC in mining cities, so as to provide methods and suggestions for the mining cities to save resources, improve the ecology, and adjust the industrial structure, this article will construct an evaluation index for the RECC of mining cities. Taking Huaihai Economic Zone as the research object, we used the entropy method to determine the index weight. Then, the TOPSIS model was used to analyze the spatial and temporal characteristics of the development of the RECC of mining cities in coal-concentrated areas during 2012–2018. After the analysis, the study found five results. (1) Except Zaozhuang, the RECC of the six mining cities in the Huaihai Economic Zone showed a steady upward trend during 2012–2018; (2) among the three subsystems, natural resources have the greatest impact on the RECC; (3) in terms of space, the carrying capacity in this region gradually has a polarization phenomenon centered on Xuzhou and Jining, and will continue to increase in the future; (4) the types of mining cities will have an impact on the change characteristics of the RECC; and (5) most cities improve the level of ecological carrying capacity (ECC) and social economic carrying capacity (SECC) at the cost of the decline of resources carrying capacity (RCC). Based on the results, the research can provide optimized reference strategies for the transformation and development of mining cities to ecological cities in Huaihai Economic Zone.