Rapid urbanization has led to significant changes in land surface temperature (LST), which in turn affect the urban thermal environment effect and the health of residents. Exploring the causes of the urban thermal environment effect will provide guidance for promoting sustainable urban development. The spatiotemporal evolution of the urban thermal environment effect within the sixth ring road of Beijing was analyzed by inversion of remote sensing data to obtain the LST in 2004, 2009, 2014, and 2019. In addition, based on multivariate spatial data, we applied the standard deviation ellipse (SDE), spatial principal component analysis (PCA), and other methods to analyze and identify the relationships between the urban thermal environment effect and its influencing factors. The results show that from 2004 to 2019, the spatial distribution of urban development and LST within the sixth ring road of Beijing were closely related, the heat island area showed a small increasing trend, and differences in the thermal environment effect between different administrative regions in different periods were obvious. The main factors affecting the urban thermal environment effect were urban construction intensity, vegetation and water bodies, socioeconomic activities, and geomorphology. It is noteworthy that human factors had a greater impact than natural factors. Among them, the positive effect of the normalized difference impervious surface index (NDBBI) and the negative effect of the fractional vegetation cover (FVC) were the most prominent. This study provides theoretical support for mitigating the urban thermal environment effect and promoting sustainable urban development.

Rapid urbanization has triggered significant changes in urban land surface temperature (LST), which in turn affects urban ecosystems and the health of residents. Therefore, exploring the interrelationship between urban development and LST can help optimize the urban thermal environment and promote sustainable development. Based on remote sensing data from 2004–2019 within the sixth ring road of Beijing, this study investigates the spatiotemporal coupling law of night time light (NTL) and LST using an overall coupling model and analyzes the degree of coordination between them using a coordination model. The spatial response law between them was also analyzed using standard deviation ellipses and bivariate spatial autocorrelation. The results show that, from the perspective of spatiotemporal evolution, the spatial distributions of NTL and LST within the sixth ring road of Beijing were closely related from 2004 to 2019, although the overall coupling of NTL and LST was initially decreased and then continuously increased. From the perspective of coordination types, the main types of coordination between NTL and LST deteriorated over time. The increase in LST lagged behind NTL from 2004 to 2009 (heating hysteresis type), while LST increased ahead of NTL from 2014 to 2019 (heating advance type). This suggests that urban development became less efficient, while LST increases became more significant. In terms of correlation, NTL and LST showed significant positive correlation and spatial positive correlation; the correlation coefficient first decreased significantly and then continued to increase. From 2004 to 2009, the temperature increase caused by urbanization was suppressed due to the 2008 Beijing Olympics and related ecological protection policies, resulting in a significant decrease in the correlation coefficient between NTL and LST. From 2009 to 2019, short-term measures taken by Beijing during the Olympic Games were no longer effective, and the opposition between urban development and related policies made the policies increasingly less effective, thereby increasing the correlation coefficient between NTL and LST, and the increase in LST was more significant. This will greatly affect the urban ecological environment and residents’ health and make the previous government investment to suppress the temperature increase all in vain. This study can provide theoretical and practical support for the development of thermal environment optimization schemes and LST mitigation strategies in Beijing and other cities.

The Yellow River Basin (YRB) serves as a crucial ecological security barrier in China, and the scientific evaluation and understanding of the formation mechanisms of ecological environment quality (EEQ) in the YRB are of great importance for implementing dynamic regional ecosystem planning and protection. Therefore, this study aims to explore the spatiotemporal evolution characteristics and formation mechanisms of the EEQ in the YRB from 2000 to 2020, based on land use remote sensing monitoring data, utilizing research methods such as the ecological environment quality index, centroid analysis, and the geographic detector. The results are as follows: From 2000 to 2020, the overall EEQ in the YRB showed a slight increasing trend, with a significant growth trend in the upstream and middle reaches, and a decreasing trend in the downstream. The spatial heterogeneity of the EEQ in the YRB was significant, with a south—high and north—low distribution pattern overall. During the study period, the spatial distribution pattern of the EEQ was relatively stable, with a notable increase in EEQ in the northwest of the YRB. The EEQ in the study area was jointly affected by natural and socio-economic factors, with precipitation, terrain fluctuation, and temperature being the dominant factors. The upstream EEQ was most affected by temperature, the EEQ of the middle reaches was most affected by precipitation, and the downstream EEQ was more vulnerable to the interference of slope and topographic relief. The influencing factors had a synergistic effect on the EEQ, and the explanatory power of socio-economic factors for a single-factor explanation of the EEQ was relatively low, but the explanatory power of the interaction between natural and socio-economic factors was significantly enhanced. These results can provide valuable insights for guiding and informing policy-making decisions related to ecological protection in the YRB.

Human activities have significantly reshaped urban thermal environments and intensified heat-related risks in rapidly urbanizing areas. Owing to its broad coverage and long-term monitoring capabilities, satellite remote sensing has become essential for tracking land surface temperature (LST) dynamics. In this study, MODIS LST data and WorldPop population density (PD) data retrieved from thermal infrared and multi-source remote sensing were used. Employing correlation analysis, standard deviational ellipse, and a coordination model, we comprehensively assessed the spatiotemporal relationship between human activities and urban heat in six Chinese megacities from 2005 to 2020. The main results revealed that: (1) although both PD and LST exhibited consistent upward trends in all cities during 2005–2020, the correlation between the two decreased while remaining significantly positive, suggesting that governance measures in megacities have helped improve urban thermal environments; (2) the correlation displayed periodic fluctuations. Dominant coordination types alternated between “heating advance” and “coordinated enhancement,” with “heating hysteresis” tending to occur alongside “coordinated enhancement,” reflecting dynamic policy adaptations to different stages of urban development; (3) significant intercity variation in the PD–LST relationship was attributed to differences in geographical conditions, development models, and industrial structures. For example, Guangzhou exhibited high PD and LST but the lowest PD–LST correlation (0.31) and the fastest decline (−1.12%/a), whereas Beijing exhibited lower PD and LST but the highest correlation (0.50) and lowest change rate (−0.60%/a). Based on these findings, we propose targeted heat environment regulation strategies tailored to each city's characteristics, providing practical guidance for enhancing heat environment governance.