Population migration and urban traffic are two important aspects of the socioeconomic system. We analyze the trends of social production and resumption of life after the coronavirus disease 2019 (COVID-19)-influenced Spring Festival in 2020 with statistics on reported cases of COVID-19 from China’s National Health Commission and big data from Baidu Migration (a platform collecting population migration data). We find that (1) the distribution of COVID-19 cases throughout mainland China has a specific spatial pattern. Provinces in eastern China have more reported cases than those in western China, and provinces adjacent to Hubei have more confirmed COVID-19 cases than nonadjacent provinces. Densely populated regions with well-developed economies and transportation are more likely to have cluster infection incidents. (2) The COVID-19 epidemic severely impacts the return of the migrant population in the Spring Festival travel rush, as demonstrated by the significant reduction in the return scale, along with the extended timespan and uncertainty regarding the end of the travel rush. Among 33 provinces, special administrative regions, autonomous regions and municipalities, 23 of them (approximately 70%) have a return rate below 60%. Hubei, Hong Kong, Xinjiang, and Inner Mongolia have the lowest return rates (below 5%), whereas the return rates in Hainan and Shandong, 272.72% and 97.35%, respectively, indicate the best trend of resumption. Due to government regulations, the population return in densely populated and well-developed regions shows a positive trend. (3) The resumption of urban traffic is slow and varies greatly in different regions. The urban traffic conditions in 22 provinces and municipalities have a more than 60% level of resumption. Guizhou and Yunnan have the highest level of resumption of urban traffic, whereas Xinjiang, Hubei, and Heilongjiang have the lowest (29.37%, 35.76%, and 37.90%, respectively). However, provinces and municipalities with well-developed intercity traffic have a lower level of resumption, mainly because of regulatory methods such as lockdowns and traffic restrictions. The increased public awareness of epidemic prevention and the decreased frequency of outdoor activities are also two positive factors slowing the spread of the epidemic. (4) Time will be necessary to fully resume social production and life throughout China. Xining and Jinan have the highest levels of resumption, 82.14% and 71.51%, respectively. Urumqi and Wuhan are the cities with the lowest levels of resumption, only 0.11% and 0.61%, respectively. Currently, 12 of 33 provinces and municipalities have levels of resumption of more than 80%; among them, Guizhou, Yunnan, and Gansu have with the highest levels of resumption and have nearly resumed the 2019 levels of work and life, whereas Xinjiang and Hubei have the lowest resumption rates, only 0.09% and 7.57%, respectively. Thus, relevant government departments should focus more on densely populated and well-developed provinces and cities when applying epidemic prevention and work resumption methods. We reveal the general conditions of the epidemic and the population return scale across China, along with urban traffic conditions and the resumption of social production and life under COVID-19, providing a scientific basis for local governments to make further decisions on work resumption.

Urban thermal environment (UTE) issue has reduced the quality of life for residents, and urban green spaces (UGs) can effectively improve the UTE. However, at a fine scale, the cooling capacity of UGs with different structures and the diurnal variation still require in-depth study. This paper, based on land use, vegetation cover, ground elevation, anthropogenic heat emission, and meteorological data, utilizes the UrbClim model to simulate high-resolution hourly air temperature (Ta) in Tianjin's urban area during summer high-temperature days. It analyzes the structural characteristics of UGs at a fine scale and reveals the diurnal cooling effect variations among UGs with various structures. The results indicate that the Urban Heat Island (UHI) within Tianjin's urban area consists of a primary heat island and several smaller heat islands scattered around it. The northern part experiences higher Ta, while the southeastern part is cooler, with the highest daytime Ta ranging from 30.7°C to 34.2°C and the lowest nighttime Ta ranging from 26.0°C to 31.7°C. The structure of UGs significantly influences the spatial pattern and fluctuation of Ta. UGs with high coverage show a diminished cooling effect at night and can reduce the extent of daily Ta fluctuations, particularly when the greenery exceeds 80%, where the effect is most pronounced. The Ta stability of patchy and aggregated UGs is stronger than that of linear and scattered UGs. Vegetation types have different regulatory effects on diurnal Ta; during the day, trees have more significant cooling effect than grasslands, while at night, this cooling effect is attenuated. Furthermore, the cooling benefits were amplified during extreme heat days. At the hottest time of the day, UGs with a high percentage of area, patchy and aggregated shape, and tree vegetation type have the best cooling effect, while at the coldest time of the night, these UGs slow down the dissipation of heat accumulated during the day and have a significant attenuation of the cooling effect. Our findings underscore the intricate relationships between the cooling effects and landscape structure of UGs, thereby aiding in the formulation of urban planning strategies to maximize the cooling benefits

The coordination and stability of the regional economy (RE) and ecological quality (EQ) are essential for the synergistic development of the Beijing–Tianjin–Hebei urban agglomeration (BTH). In this paper, based on remote sensing data and economic statistics data, this paper analysed the current situation and evolution of the RE and EQ in the BTH region. Based on the coupled coordination degree (CCD) model, this paper has developed an evaluative framework and quantifies the spatiotemporal coupled coordination of the RE and EQ in the BTH region from 2000 to 2020. The results show that: (1) in 2020, the GDP of the poverty-stricken counties (PSCs) around BTH accounted for 4.57% of the total BTH region, and the area of high-quality ecosystems, Net Primary Productivity (NPP), soil conservation, water conservation, and sand fixation accounted for more than 40% of the total BTH region; (2) the GDP growth of the PSCs accounted for 4.45% of the total growth in BTH, the reduced area of high-quality ecosystems accounted for 21.04%, and the increase in NPP, soil conservation, water conservation, and sand fixation accounted for more than 40% of the total growth in the BTH region; (3) the CCD of the RE and EQ in the BTH region showed a tendency to increase, but the gap between the regions gradually expanded, and the development type changed from a lagging RE to a lagging EQ, in which the coupled coordination grade of the PSCs was in a dissonance stage for a long time, and the level of economic development had to improve. Deepening the understanding of the spatiotemporal coupling relationship between the RE and EQ and adopting appropriate development policies is of great significance for achieving the coordinated and integrated development of the BTH region.