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Increasingly growing consumption-based water use (WU) combined with climate change have exacerbated water stress globally and regionally, yet little is known about how the WU change is affected by metacoupled processes which involve human-nature interactions across space; within and across adjacent and distant places. This study aims to unveil the spatio-temporal pattern of China's WUs during 2007-2015 and its underlying local and non-local drivers. Results show that China's total WU exhibited an upward trend from 386.7 billion m³; in 2007 to 431.2 billion m³ in 2012 but dropped to 412.6 billion m³ by 2015. Widespread and continuous water use efficiency improvement contributed most to offsetting the increase in WU driven by the rising affluence and growing population in the context of rapid urbanization and industrialization. Economic structure drove a relatively large WU reduction (responsible for -23.7% of the WU change during 2007-2015), in line with China's ongoing transform from a capital investment-driven economy to a consumption-driven one and decoupling economic growth from environmental pressure. The population share representing the non-local factor of migration effect was large enough to be seen clearly in the changing WUs across China: the WUs of coastal areas ascended while inland areas descended, which was in accordance with migration patterns. Our findings could make a valuable contribution to decision-making in identifying hotspot areas, charting systematic courses for sustainable water use, and combining demand-oriented and supply-oriented measures., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Abstract China's rapid urbanization has aggravated its air pollution problems and subsequently results in increased interests in the relationship between urbanization and PM 2.5 concentrations. Currently, research on the ways that urbanization directly influences air quality are comparatively mature; however, quantification of the spillover effect of urbanization on PM 2.5 concentrations in adjacent regions remains understudied. Additionally, urbanization is a multi-dimensional phenomena in China and it is important to distinguish the ways in which the multiple aspects of urbanization influence PM 2.5 concentrations. Taking the Beijing-Tianjin-Hebei Urban agglomeration of China as an example, this study explored the spatio-temporal change and spatial dependence pattern of PM 2.5 concentrations, and further examined and compared the unique impacts of the multiple dimensions of urbanization on PM 2.5 concentrations. The results showed that spatial dependence of PM 2.5 generally took place over the range of 200 km in the study area. Economic urbanization had a much stronger influence on air quality than land urbanization or population urbanization; it was determined to be the best indicator to represent the impact of urbanization, especially the spillover effect of urbanization on PM 2.5 concentrations in adjacent regions. Over the period 2000–2010, the impacts from both local and neighboring economic urbanization on PM 2.5 concentrations increased significantly. In contrast, land urbanization mainly exerted influence on air quality in focal regions. Population urbanization showed no significant direct or spillover effects on PM 2.5 concentrations in the whole urban agglomeration. This study provides evidence that the influence of urbanization within and across cities must be considered when conducting joint air pollution control in an urban agglomeration. PM 2.5 taxes based on the diffusion and transfer of environment pressures are one possible policy mechanism that could help to account for the spillover effect of economic urbanization on air quality. System-based approaches and flow-centered governance are two suggested ways to coordinate the management of both urbanization and air quality. Highlights • Spatial dependence of PM 2.5 concentrations occurs over the range of 200 km in BTH. • Spillover effect of urbanization on PM 2.5 occurs through various approaches. • Development of economic, land, population urbanization is inconsistent in BTH. • Economic urbanization can best indicate the impact of urbanization on PM 2.5. [ABSTRACT FROM AUTHOR]

China's rapid urbanization and severe PM 2.5 -dominated air pollution have received worldwide attention. It is important to reveal how urbanization affects the generation of PM 2.5 . A growing amount of research has examined the local urbanization impact on PM 2.5 concentrations. However, few studies have quantified the influence of neighboring urbanization in terms of the spatial dependence of PM 2.5 concentrations. Some studies considered these spatial effects but overlooked the natural controlling factors. In a comparative view among Beijing-Tianjin-Hebei, Yangtze River Delta, and Pearl River Delta urban agglomerations in China during 2000–2010, the direct and spillover effects of urbanization on PM 2.5 concentrations were explored using spatial regression models that set urbanization and natural indicators as core and controlling variables, respectively. The results showed natural controlling factors were statistically significant; their inclusion in the regression model improved the reliability of estimation. It was also found that the spillover effect of urbanization substantially contributed to the spatial dependence of PM 2.5 concentrations. Nevertheless, the direct and spillover effects of urbanization on PM 2.5 concentrations differed among urban agglomerations and changed over time due to the complexity of urbanization processes. For the Beijing-Tianjin-Hebei urban agglomeration in 2010, the direct effect showed that the urban PM 2.5 concentration increased by 0.138% averagely for every 1% increase of the urbanization level. Likewise, the spillover effect showed that urban PM 2.5 concentration increased by 0.340% for every 1% increase in the average urbanization level of its neighboring cities. In addition, the conflict between PM 2.5 abatement and urbanization level development in the three urban agglomerations was alleviated after 2007, reflected by the simultaneous improvement of urbanization level, urban air quality, and urbanization quality (the ratio of urbanization level to urban air pollution). This study provides policy makers with more detailed characterization about the impact of urbanization on PM 2.5 concentrations, and it is suggested that not only the direct effect but also the spillover effect should be taken into account in guiding air pollution control of urban agglomerations. [ABSTRACT FROM AUTHOR]

How to assort with the relationship between mountain development and ecological protection is a key issue during the process of mountainous urban construction. Ecological carrying capacity (ECC), as the key to measuring regional sustainable development in terms of society, economy and ecology, provides an approach to assess urban development potential in mountain areas. Taking Dali Bai Autonomous Prefecture in Yunnan Province, China as a study area, this study has explored the conceptual framework for ECC in view of coupled human and natural systems (CHANS), and has constructed an index system using aspects of ecosystem vigor (EV), resources and environmental carrying capacity (RECC), and social development ability (SDA). The results at the county level showed that: (1) Dali City had the highest EV and SDA, with a relatively good ecological background, stable geological environment, and more concentrated population and flourishing urbanization. Yunlong County occupied the best RECC for its relatively abundant stock of water and land resources. Due to well-balanced ecosystem stability maintenance, resource utilization, and human development, Yunlong County possessed the highest ECC all over the prefecture; (2) the study area can be grouped into five categories considering trade-offs between mountain development and ecological protection. That is, priority areas for conservation, priority areas for development, areas suitable for short-term conservation but long-term development, areas suitable for short-term development but long-term conversation, and areas reserved for future appropriate development. This research could help to identify the approach to sustainable mountain development from the perspective of CHANS, and to make effective contribution to urban development decision-making in mountainous areas. [ABSTRACT FROM AUTHOR]

[Display omitted] • Vegetation coverage increased along with urbanization in PRD during 2000–2012. • Relationship between vegetation and urbanization varied at 1−20 km scales. • Mean local variance was used to identify appropriate analysis scale. • NTL-LAI appropriate analysis scale was mainly affected by urbanization level. Accurate quantification of the relationship between urbanization level and vegetation coverage can provide scientific support for urban sustainable development. However, the interaction between them across multi-scales is under-researched because of its complexity. Based on climate change (i.e. precipitation, temperature and solar radiation), partial correlation relationship between urbanization level (nighttime light, NTL) and vegetation coverage (leaf area index, LAI) at different scales (1–20 km) in the Pearl River Delta (PRD) was explored. Mean local variance was used to determine the appropriate scale of the relationship, at which these metrics could have the minimum information missing. The consistency in appropriate analysis scales of NTL, LAI, and NTL-LAI, was quantified to identify which factor more influenced the appropriate analysis scale of NTL-LAI correlation. The results showed from 2000 to 2012, the urbanization level increased at the rate of 0.58/yr and the average LAI increased slowly at the rate of 0.02 m2/m2/yr. The partial correlation between NTL and LAI depicted that urbanization promoted vegetation coverage in the PRD. Meanwhile, the appropriate analysis scale of NTL-LAI correlation was more determined by the analysis scale of urbanization level, than that of vegetation coverage. This study revealed the scale effect of the relationship between urbanization level and vegetation coverage, and identified the determine factor of appropriate analysis scale of the relationship, which could help for the scale selection in related studies. [ABSTRACT FROM AUTHOR]

• Cooling intensity of all types of waterbody patches were quantified and compared. • The patch size of waterbody was the dominant factor of cooling intensity. • Local socioeconomic development strongly impacted the cooling effect of waterbody. • Threshold value of cooling efficiency of different waterbodies were identified. Climatic warming and urbanization have exacerbated urban heat island (UHI) effect globally. Waterbodies have significant cooling effect while the current UHI mitigation researches mostly focus on green spaces. Although the cooling effect of waterbodies has been highlighted and measured in previous studies, the impact of local socioeconomic development surrounding the waterbodies remains unclear. The scarcity of land resource in the city has also posed urgent need to explore cooling efficiency of waterbody patch size. Highly urbanized and densely scattered with waterbody, the Pearl River Delta (PRD) urban agglomeration has suffered severe UHI effect. Taking four PRD cities as the case study area, this study analyzed the impact of local socioeconomic development on the daytime cooling intensity of waterbodies, and identified the dominant impact factor as well as the threshold value of efficiency (TVoE) in diversely developed areas. The results showed that the cooling intensity of waterbodies had obvious spatial heterogeneity with an average of 1.1 °C and a maximum of 5.54 °C, which was dominated by patch size and strongly affected by local socioeconomic development. The mean cooling intensity increased along with the increasing of local socioeconomic development, and the TVoEs of waterbody patch size were 0.49 ha, 0.55 ha and 0.70 ha in such three levels of local socioeconomic development as low, medium and high, respectively. The results can provide quantitative guidance for blue landscape planning in regard to UHI effect mitigation. [ABSTRACT FROM AUTHOR]

Abstract The rapid process of urbanization, accompanied by the sharp increase of urban population and expansion of artificial surface, has resulted in the loss of natural ecosystems and the degradation of ecosystem services. Identifying and protecting key places that have high importance for ecological sustainability are great challenges. Ecological security patterns are such an integrated approach to protecting regional ecological sustainability. In this study, taking Yunnan Province, China as a case study area, ecological sources were identified through ecosystem services, and circuit theory was used to model ecosystem processes in heterogeneous landscapes via calculating the ‘resistance’ or ‘current’, and thus to identify ecological corridors and key ecological nodes. The results showed that, ecological security patterns included 66 ecological sources, 186 ecological corridors, 24 pinch-points and 10 barriers. In details, the ecological sources were mainly distributed in the southwest and northwest of Yunnan Province, with the ecological corridors locating along the high mountains, and both ecological sources and corridors were mostly covered with forest land. Pinch-points covered by forest land and cultivated land, were distributed in the middle of Yunnan Province along the rivers. Approximately 75.9% nature reserves were located in the identified ecological sources, and the remainings were mainly distributed in eastern Yunnan Province with small area, showing the effectiveness in identifying ecological security patterns. Among 81 projects of low–slope hill development carried out in Yunnan Province, 46.9% showed potential human stress on regional ecological security. Based on ecosystem services and circuit theory, this study provides a new approach to identifying the spatial range of ecological corridors and the specific location of key nodes for effective ecological conservation and restoration. Graphical abstract Unlabelled Image Highlights • Ecosystem services were used to identify ecological source. • Ecological corridor, pinch point and barrier were identified using circuit theory. • 38 development projects showed potential stress on ecological security patterns. [ABSTRACT FROM AUTHOR]