RESUMEN
Surface urban heat island (SUHI) exposure significantly harms human health during rapid urbanization. Identifying the areas and demographic groups under high SUHI exposure is critical for mitigating heat-related hazards. However, despite broad concern in US-European countries, rare studies discuss the diurnal SUHI exposure of demographic subgroups across Local Climate Zones (LCZs) in Chinese cities. Therefore, taking Chongqing as the case study, we measured the diurnal SUHI exposure of demographic subgroups (e.g., gender, age, and income) across different LCZs (compact, open, and sparsely-built zones) by coupling the ECOSTRESS data and mobile phone signaling data. The results indicated that Chongqing's compact high/middle-rise zones suffered a higher SUHI exposure due to high land surface temperature (LST) and a larger size of population than open zones. Despite a relatively low population density, extremely high LST in compact low-rise zones (e.g., industrial parks) contributes to considerable accumulated SUHI exposure. The SUHI exposure risk exhibited the differences between daytime and nighttime, resulting from SUHI variation and population flow. The demographic analysis showed that Chongqing's demographic subgroups are exposed disproportionately to SUHI. Elderly groups suffered relatively high exposure in compact high-rise zones. Low-incomers witnessed a high exposure in open zones. These findings call for alleviating SUHI exposure risk by targeting vulnerable groups and high-intensity exposure areas.
Asunto(s)
Monitoreo del Ambiente , Calor , Humanos , Anciano , Ciudades , Monitoreo del Ambiente/métodos , China , Densidad de Población , TemperaturaRESUMEN
The reasonable distribution of urban green space (UGS) is a topic that urban researchers have been exploring for a long time. Solving the imbalance between the supply and demand of UGS plays an important role in improving the health level of a city. This study examines the central urban area of Hefei as an example. We developed a modified Gaussian two-step floating catchment area method and used the path planning model of Gaode Map to evaluate the accessibility of UGS under different transportation modes and different time thresholds while integrating mobile phone signaling data. Additionally, a fine-scale analysis of the actual supply and demand relationship of UGS was conducted by integrating the accessibility evaluation results with the recreational situation of UGS to analyze the deviation of supply and demand to further discuss the spatial distribution equilibrium of UGS. The main conclusions are as follows. (1) The spatial distribution of UGSs in the central urban area of Hefei is uneven. Different time thresholds and different transportation modes have a significant impact on the UGS accessibility evaluation results. (2) With the increase in the time threshold or travel distance, the number of grids above the moderate accessibility level generally increases. The spatial distribution of the grids with moderate, high and highest accessibility level present different patterns of contiguous, clusters, and spots distribution. (3) After combining these results with the actual recreational situation of UGS, we found that the overall demand in the central urban area exceeds the supply at the 15-min threshold, while the overall supply exceeds the demand at the 30-min threshold. The grids with balanced supply and demand or more supply than demand have comprehensive parks with a moderate population density and strong road connectivity in the neighborhood. This study strengthens the data granularity and improves the accuracy of accessibility evaluation by integrating mobile phone signaling data with the path planning model of Gaode Map. Also, we evaluate the accessibility with multi-transport modes and different time thresholds, which can bring more practical guidance for optimizing the distribution of UGS.
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Teléfono Celular , Parques Recreativos , Ciudades , Viaje , Características de la ResidenciaRESUMEN
Constructing an ecological security pattern by matching the supply and demand of ecosystem services is of great significance for Shenzhen, China. To determine the strategic positioning of sustainable development pioneers and benchmarks for human well-being in a pilot demonstration area of socialism with Chinese characteristics, we selected water yield, carbon sequestration, and recreational services to identifiy the integrated supply and demand status of ecosystem services in Shenzhen using the InVEST model, ecological supply-demand ratio, cell phone signalling data analysis, and circuit theory. An ecological security pattern based on the matching of supply and demand of ecosystem services was constructed. We further examined the impacts of different delimitation boundaries on the area and number of ecological sources. The results showed that the comprehensive ecological supply-demand ratio in Shenzhen generally showed a distribution pattern of abundant in the east and scarce in the west. Among them, water yield services met the demand in terms of quantity and spatial distribution, but carbon sequestration services can not. Recreational services met the demand in terms of quantity, but their spatial distribution was extremely uneven. We identified 25 ecological sources covering a total area of 347.62 km2 and 34 ecological corridors with a total length of 346.06 km. The ecological source area was large in the east and small in the west, while the length of the corridors showed the opposite distribution pattern. Different delineation boundaries had different effects on the area and number of ecological sources. Primary, secondary, and tertiary ecological source areas cover 347.62, 520.84, and 557.58 km2, respectively, showing a gradual increasing trend, the numbers of ecological sources were 25, 35, and 32, showing an increasing then decreasing trend. In Shenzhen, there were important ecological patches that were not included in the ecological control line, and some patches within the ecological control line had poor ecological sustainability. Targeted protection and management policies could be formulated based on such pattern. The results could provide spatial guidance for the delimitation of ecological management and control units in Shenzhen.
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Conservación de los Recursos Naturales , Ecosistema , Secuestro de Carbono , China , Humanos , AguaRESUMEN
Transit-oriented development (TOD) has been regarded as an effective way to improve urban vibrancy and facilitate affordable, equitable, and livable communities in metro station areas (MSAs). Previous studies placed great attention on the interplay between the MSA-level built environment and overall human activities while neglecting the heterogeneity among different age groups. To address this gap, we leverage the mobile phone signaling data to quantify the spatio-temporal distribution of the MSA-level human activities among different age groups as measured by the vibrancy index (VI). Furthermore, we investigate the impact of the MSA-level built environment on the VI and its intergenerational differences by employing multiple linear regressions based on multi-sourced data. To this end, Chengdu-a TOD-thriving megacity in China-is chosen as a case study. The results indicate that: (1) Residential and bus stop density are positively associated with the VI. And the magnitudes of the correlation coefficients are similar among different age groups. (2) Distance to CBD is negatively associated with the VI of teenagers (12-18 years), middle-aged adults (40-59 years), and older adults (above 60 years) but unrelated to the VI of young adults (19-39 years). (3) Employment density is positively associated with the VI of young and middle-aged adults but insignificantly associated with the VI of teenagers and older adults. (4) The correlations between the floor area ratio and the VI are positive for all age groups. As age increases, the significance of such correlations becomes more pronounced. (5) Streetscape greenery shows a more significant positive correlation with the VI of teenagers and older adults as compared to those of young and middle-aged adults. (6) Significant negative correlations exist between housing price and the VI of different age groups. The findings can inform the development and design of vibrant TOD communities.
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Entorno Construido , Características de la Residencia , Adolescente , Anciano , China , Costos y Análisis de Costo , Vivienda , Humanos , Persona de Mediana Edad , Adulto JovenRESUMEN
Previous studies on the supply and demand of ecosystem services (ES) mainly focused on inter-annual changes, and no studies have explored the impact of demographic change on the ES supply and demand on fine-grained time scales. Thus, taking Shenzhen as an example, the status of ES supply and demand, as well as diurnal population changes and their impacts on cultural services were analyzed at different time periods using mobile phone signaling data, ecological supply-demand ratio (ESDR), Geo-Informatic Tupu, InVEST model and buffer zone. The results showed that the population declines successively on workdays, weekends and holidays, and that the daytime population is greater than the nighttime. Water yield services can basically meet the demand in terms of quantity and spatial distribution, however, carbon sequestration and cultural services showed the opposite results. The main type of ESDR changes in cultural services are the mutual conversion of deficit and balance, and these are concentrated in areas with high forest coverage and small populations, but frequent population changes. In addition, when the fixed population is too large, the use of time-varying population data will conceal the impact of demographic changes on ES supply and demand, and other data are needed for auxiliary analysis. Overall, this study provides a new research perspective for the ES supply and demand and can provide a theoretical basis for refined sustainable urban management.