Poor indoor air quality reduces the comfort experienced in the environment and can also harm our physical health. Mechanical ventilation design plays an important role in improving the indoor environment and the safety of public toilets. Therefore, in this study, we aimed to evaluate public toilet ventilation design schemes through a digital twin to determine the most effective scheme for reducing indoor pollutant concentrations. In this study, we used Autodesk Revit to create a digital twin BIM of different ventilation systems. We simulated the diffusion of pollutants in these models using computational fluid dynamics (CFD)-based methods, and we used DesignBuilder to simulate building energy consumption. From the perspective of architectural design, we determined measures important for reducing the concentration of air pollutants by increasing the number and volume of air exchanges and controlling the installation height of exhaust vents. The results show that the ventilation design of an all-air air conditioning system with an exhaust height of 400 mm can remarkably improve the indoor environmental health and ventilation efficiency of public toilets, while consuming 20.4% less energy and reducing carbon emissions by 30,681 kg CO₂.

The outdoor wind environment and thermal environment are important factors affecting human comfort in cold winter conditions. The spatial layout of plant communities plays an important role in improving the outdoor microclimate and improving outdoor comfort. In order to explore the positive effect of plant layout on outdoor comfort in cold winter, this study took Xuzhou Tangfang Middle School with typical layout characteristics as the research object. In this study, we simulated the wind environment of these models using computational fluid dynamics (CFD) methods and the outdoor thermal environment using Ecotect (2011), and used linear regression and one-way ANOVA for mathematical statistics. The wind environment and Universal Thermal Climate Index (UTCI) of campus outdoor activities distributed in different spaces were analyzed and evaluated. The research results showed that the superposition of wind and thermal environments identified the key areas of the campus (cross-flow area and corner flow area) and showed a negative correlation. The staggered layout of the three plant combinations increases the wind prevention efficiency by 39.4%. At the same time, this study established the linkage mechanism of campus plant layout, environmental microclimate, and activity area comfort, which effectively improved outdoor human comfort in cold winter. This research can provide a reference for the remediation and improvement of the comfort of the same type of campus, and also provide data support and reference significance for the research on the outdoor pedestrian environment in winter.

(1) Background: Achieving harmonious human–land relations is one of the key objectives of sustainable urban–rural development, and the degree of decoupling of permanent population levels from changes in construction land use is an important factor in related analyses. Due to the existence of huge urban–rural differences, rethinking China’s human–land relations from the perspective of integrating urban and rural areas is of great value for the advancement of high-quality urban–rural development. (2) Methods: By studying the lower reaches of the Yangtze and Yellow Rivers of China, and based on data from the second and third national land surveys of China, this paper analyzes the spatio-temporal evolution of urban and rural population, construction land use, and human–land relations from 2009 to 2019 using exploratory spatial data analysis (ESDA) and a decoupling model; in addition, this paper proposes a differentiated zoning management strategy and establishes a new framework that integrates evolutionary patterns, human–land relations, spatial effects, and policy design. (3) Results: The geographic distribution patterns of urban and rural population and construction land use remained stable over time, with high levels of spatial heterogeneity, agglomeration, and correlation. Changes in urban and rural population levels and construction land use are becoming increasingly diversified and complex, with both increases and reductions existing side by side. Based on a Boston Consulting Group matrix, the evolution patterns of urban and rural population and construction land use are divided into four types, referred to as star-cities, cow-cities, question-cities, and dog-cities. Over the time period examined in this paper, the spatial autocorrelation of urban land evolution patterns turned from negative to positive; however, that of rural land, as well as those of urban and rural population evolution patterns, were statistically insignificant. Urban human–land relations are coordinated, in general, and are mostly in a state of either weak decoupling or expansive coupling. In contrast, rural human–land relations are seriously imbalanced, and most of them are in a state of strong negative decoupling. Human–land relations are dominated by regressive changes in urban areas but remain unchanged in rural areas. Cold- and hot-spot cities are concentrated in clusters or in bands, forming a core-periphery structure. The formation and evolution of the decoupling relationship between construction land use and permanent population are the results of multiple factors, including urbanization, industrialization, globalization, and government demand and policy intervention. The interaction effects between different factors show bifactor enhancement and nonlinear enhancement, with complex driving mechanisms and large urban–rural differences. It should be highlighted that the influence intensity, operation mechanism, and changes in the trends for different factors vary greatly. Urbanization rate, gross domestic product, and government revenue are key factors that exert a strong direct driving force; international trade, foreign direct investment, and per capita GDP are important factors, while the remaining factors are auxiliary factors that remain heavily dependent on interaction effects. (4) Conclusions: To further transform human–land relations from imbalanced to coordinated, we divide the study area into four area types based on the concept of urban–rural community: urban and rural intensive policy areas, urban intensive policy areas, rural intensive policy areas, and urban and rural controlled policy areas. Furthermore, we put forward suggestions on the differentiated management of land use for the four types of policy areas.