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• We developed a method to quantify seasonal supply–demand variations of ecosystem service. • Water provisioning service is pronouncedly mismatched in winter. • The developed method based on SWAT has potential to estimate other water-related services. • Reservoirs are important for addressing unmatched supply–demand relation at the watershed scale. The match and mismatch between the supply and demand of ecosystem services (ESs) are closely related to watershed sustainable development. Previous studies have mainly focused on annual or interdecadal matching relationships, and little is known about the seasonal variations of the ES supply–demand relationship. Based on the SWAT (Soil and Water Assessment Tool) model and statistical data, we took the Guanting Reservoir Basin, a transitional ecosystem from semi-arid areas to arid areas, as the study area to analyze the supply and demand of water provisioning services and soil conservation services and identified their matching relationship on the seasonal scale. The results showed that the water provisioning services was in short supply, with a supply–demand ratio of 0.81, whereas the supply of soil conservation services was in excess of demand. In terms of seasonal variation, the mismatch of water provisioning services was particularly severe in winter, followed by that in spring. The mismatch of soil conservation services was relatively severe in winter, followed by that in summer. Such mismatches imply that we must pay attention to the misallocation of resources caused by seasonal variations. It is crucial that policy-makers consider the role of reservoirs and water transfer in providing seasonal water sources for sustaining water resources in transitional areas, and optimize land management to prevent the aggravation of soil erosion in winter. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ecosystem service conservation area was used to guide urban landscape planning. • Ecosystem services losses will decrease substantially when considering conservation. • Protecting woodland and cropland for reducing ecosystem services losses. • Conserving ecosystem services can also promote a coordinated development of cities. Abstract Planning urban landscape is essential for maintaining key ecosystem services (ESs) in rapidly urbanizing areas and has become one of the key questions in urban ecology and landscape ecology. In this study, we simulated the urban landscape dynamics in the Beijing-Tianjin-Hebei (BTH) urban agglomeration in China during the period of 2013–2040 under different ES conservation scenarios by combining ES conservation priority areas, the Land Use Scenario Dynamics-urban (LUSD-urban) model, and scenario analysis to explore approaches to planning urban landscapes with the goal of maintaining and conserving key ESs. We found that the key ESs could be effectively maintained with urban landscape planning in the BTH urban agglomeration. The loss of food production (FP) under the provisioning service conservation scenario will be 80.88% lower than that under the business-as-usual (BAU) scenario, and the loss of regulating services under the regulating service conservation scenario will be 1.42–10.34% lower than that under the BAU scenario. The loss of recreation service (RS) under the cultural service conservation scenario will be 41.52% lower than that under the BAU scenario. The integrative conservation scenario will be the best scenario to maintain ESs because the losses of FP, carbon storage (CS), water retention (WR), and air purification (AP) will be 29.31–78.49% lower than those under the BAU scenario. Protecting cropland and woodland will be an effective strategy in planning urban landscape to maintain key ESs. When cropland and woodland were protected, ES losses under the integrative conservation scenario will be 85.67–98.58% lower than those under the BAU scenario. Promoting the coordinated development of cities of different sizes will be another effective strategy in planning urban landscape. Under the best scenario of maintaining key ESs, i.e., the integrative conservation scenario, ESs in megacities and large cities can be protected, while ES losses will mainly occur in medium-sized cities. The ES losses in medium-sized cities will account for 60% of the total losses across the entire region. To ensure sustainable development in the BTH urban agglomeration, we suggest that effective policies and regulations be implemented to protect cropland and woodland areas and to promote the coordinated development of cities of different sizes to maintain key ESs. [ABSTRACT FROM AUTHOR]

Assessing the impacts of urban expansion on ecosystem services (ESs) is fundamental to understanding urban sustainability. However, little is known about the intensity of simultaneous losses of ESs over time caused by urban expansion. Taking Beijing as an example, this study sought to simulate the historical and potential impacts of urban expansion on the simultaneous losses of main ESs. We projected the impacts of urban expansion on the simultaneous losses of main ESs from 1990 to 2013 and simulated the potential impacts from 2013 to 2040 by combining ES mapping models, an urban expansion model and statistical methods. The results show that food production, water conservation, habitat quality, carbon storage, and air quality regulation in Beijing from 2013 to 2040 will decrease by 20.70%, 8.69%, 6.45%, 5.76%, and 3.92%, respectively. Meanwhile, the simultaneous losses of water conservation, habitat quality, carbon storage, and air quality regulation will be aggravated. Increases in the replacement of forest land by urban land will be the main cause for the aggravation of simultaneous losses of ESs. From 2013 to 2040, 11.08% of expanded urban land will replace forest land, which is much higher than the 3.24% change from 1990 to 2013. Thus, more attention should be paid to protecting forest land and cropland with high ES values in rapidly urbanized regions. [ABSTRACT FROM AUTHOR]

Abstract: Representing agent heterogeneity is one of the main reasons that agent-based models become increasingly popular in simulating the emergence of land-use, land-cover change and socioeconomic phenomena. However, the relationship between heterogeneous economic agents and the resultant landscape patterns and socioeconomic dynamics has not been systematically explored. In this paper, we present a stylized agent-based land market model, Land Use in eXurban Environments (LUXE), to study the effects of multidimensional agents’ heterogeneity on the spatial and socioeconomic patterns of urban land use change under various market representations. We examined two sources of agent heterogeneity: budget heterogeneity, which imposes constraints on the affordability of land, and preference heterogeneity, which determines location choice. The effects of the two dimensions of agents’ heterogeneity are systematically explored across different market representations by three experiments. Agents’ heterogeneity exhibits a complex interplay with various forms of market institutions as indicated by macro-measures (landscape metrics, segregation index, and socioeconomic metrics). In general, budget heterogeneity has pronounced effect on socioeconomic results, while preference heterogeneity is highly pertinent to spatial outcomes. The relationship between agent heterogeneity and macro-measures becomes more complex when more land market mechanisms are represented. In other words, appropriately simulating agent heterogeneity plays an important role in guaranteeing the fidelity of replicating empirical land use change process. [Copyright &y& Elsevier]

• A new method was developed to identify urban haze islands. • The new method can accurately and effectively delineate urban haze islands. • Two-thirds of Chinese cities had urban haze islands. • The new method can be used to depict other urban-rural gradients. Air pollution has great impacts on both human health and economic development. The difference in air pollution concentrations between urban and rural areas (urban haze island) is a widespread phenomenon. However, a method that can effectively depict the features of this phenomenon remains lacking. This study developed a method based on the concentric ring approach and modified sigmoid function to identify urban haze islands and extract three features: the background value of urban haze islands (BUHI), the intensity of urban haze islands (IUHI) and the extent of urban haze islands (EUHI). Using this method, we analyzed the PM 2.5 concentration data from 346 Chinese cities in 2016 and examined the spatial characteristics and driving factors of the three features of urban haze islands. The results showed that about two-thirds (218/346) of Chinese cities had a significant urban haze island phenomenon, with an average BUHI of 36.8 μg/m3, an IUHI of 11.3 μg/m3, and an EUHI of 7.7 km. The developed method can successfully capture the variations of PM 2.5 concentration, and the RMSE of the fitting curve was 0.46 μg/m3. On the national scale, natural factors had a greater impact (with the standardized regression coefficients varying from −0.74 ~ 0.80) on the BUHI and IUHI than socioeconomic factors (-0.32 ~ 0.32), while socioeconomic factors had a greater impact (0.29 ~ 0.38) on the EUHI than natural factors (−0.23 ~ 0.17). This study proposes a new and simple method to identify urban haze islands with high efficiency and wide applicability. Our results can be helpful for understanding urban-rural environmental differences and providing guidance for policymakers. [ABSTRACT FROM AUTHOR]

• A framework to assess community resilience using nighttime light remote sensing data. • Geographical disparities of economic disturbance and recovery in Hurricane Katrina. • Community resilience is related to various factors at different phases of a disaster. • Fill the gap of empirical data and methods for measuring community resilience. A major challenge for measuring community resilience is the lack of empirical observations in disasters. As an effective tool to observe human activities on the earth surface, night-time light (NTL) remote sensing images can fill the gap of empirical data for measuring community resilience in natural disasters. This study introduces a quantitative framework to model recovery patterns of economic activity in a natural disaster using the Defense Meteorological Satellite Program-Operational Linescan System (DMSP-OLS) images. The utility of the framework is demonstrated in a retrospective study of Hurricane Katrina, which uncovered the great economic impact of Katrina and spatial variation of the disturbance and recovery pattern of economic activity. Environmental and socio-economic factors that potentially influence economic recovery were explored in statistical analyses. Instead of a static and holistic index, the framework measures resilience as a dynamic process. The analysis results provide actionable information for prompting resilience in diverse communities and in different phases of a disaster. In addition to Hurricane Katrina, the resilience modeling framework is applicable for other disaster types. The introduced approaches and findings increase our understanding about the complexity of community resilience and provide support for developing resilient and sustainable communities. [ABSTRACT FROM AUTHOR]

Spatiotemporal patterns of global air pollution are of great significance to environmental management and public health. Studies have revealed the changes in the concentration of dust and sea-salt removed fine particulate matter (PM 2.5) pollution (DSRPP). However, the spatial characteristics of DSRPP on multiple scales remain unclear. Therefore, we combined the latest global estimates of the PM 2.5 dataset and landscape metrics to investigate the spatiotemporal patterns of DSRPP across global and national scales from 2000 to 2016. We found that the area of DSRPP increased from 1,146,800 km2 to 3,929,800 km2 between 2000 and 2016, a factor of 2.43. The DSRPP became more structurally fragmented and geometrically complex, with the patch density and the landscape shape index of DSRPP increasing by 133.3% and 24.5%, respectively. More than 90% of the DSRPP were concentrated in the middle income countries, especially in India and China. Specifically, the DSRPP in China exhibited a sprawling process before 2007 but a dissipating process after 2007 under the great efforts of the Chinese government in mitigating air pollution, while DSRPP in India remained an aggregation trend. The potential threat to public health posed by the DSRPP increased over time. Populations living in the areas with the DSRPP increased by 141.2% from 2000 to 2016 due to the deterioration of air quality and demographic change. Thus, we suggest that effective actions should be taken to control the main sources of anthropogenic emissions and mitigate the negative effects of DSRPP on public health in the future, especially in the middle income countries such as China and India. Image 1 • The area of global DSRPP increased by a factor of 2.43 from 2000 to 2016. • The global DSRPP became more spatially fragmented and complex from 2000 to 2016. • China's DSRPP sprawled before 2007 but dissipated thereafter through emission control. • The threat of global DSRPP to public health increased over time. [ABSTRACT FROM AUTHOR]

• Dynamics of built-up land in floodplains (BLF) affect flood exposure and risk. • However, the BLF growth mode and its flood impacts had not yet been assessed. • We revealed BLF growth modes in terms of patch sizes and expansion types. • The growth modes were significantly associated with flood occurrence. • Policymakers should be aware of the various impacts of the BLF growth modes. Built-up land in floodplains (BLF) is a vital indicator of the socio-hydrological system, and its dynamics are key to understanding and managing flood risk. However, previous studies have neglected the impacts of BLF growth modes (e.g., patch sizes and expansion types) on flood vulnerability. This paper fills this gap by assessing the BLF's growth modes and revealing their divergent impacts on flood vulnerability using a case study in the Yangtze River Economic Belt (YREB), China. The results show that the BLF has nearly doubled in the YREB during 1990–2014. A considerable proportion (35.43%) of the BLF growth is scattered in small patches (≤1 km2), which have a much stronger correlation with flood occurrence than that of the other patch sizes. In terms of expansion types, the edge-expansion type dominates 57.52% of the BLF growth, followed by the leapfrogging and infilling expansions. Both the leapfrogging and the edge-expanding BLFs are significantly associated with flood occurrence, while the infilling type is not. The patch size and expansion type can thus influence the vulnerability of BLF patches, which is also supported by real-world cases. These findings enrich a general understanding of BLF growth and its impacts on flood vulnerability. The scientific community and policymakers should pay attention to not only the quantity of BLF growth, but also its spatial arrangement. [ABSTRACT FROM AUTHOR]

[Display omitted] • We develop a framework to estimate future Flood Regulation Service (FRS) dynamics. • The framework considers the joint impacts of both climate change and urbanization. • Future FRS supply–demand imbalance will continue to intensify. • Future impacts of climate change in Baiyangdian Lake Basin cannot be ignored. • Cities should actively adapt to climate change to reduce flood risks in the future. Estimating the supply–demand relationship's future dynamics and trend of Flood Regulation Service (FRS) is important for preventing flood risks and choose an appropriate future development path. Less attention has been given to assessing the future trends in this relationship under the joint influence of climate change and urbanization. This paper aims to quantify future trends in the FRS supply–demand relationship under the joint impacts of climate change and urbanization. To this end, we took the Baiyangdian Lake Basin as an example and developed a "Climate Change-Urbanization-FRS supply and demand" framework by combining future climate scenarios from the ScenarioMIP (Scenario Model Intercomparison Project) dataset and socioeconomic data from the SSPs (Shared Socioeconomic Pathways) to estimate the FRS supply and demand dynamics during the period from 2020 to 2050. The results show that the framework has a reasonable ability to estimate the FRS supply–demand relationship. The correlation coefficients between estimated supply–demand ratios and the historical values exceeded 0.9. The average FRS supply–demand ratio among the four scenarios shows a significantly downward trend between 2020 and 2050. The FRS is expected to decrease by 0.159 (36.6 %), resulting in the imbalanced area increasing from 38.3 km2 (4.1 % of the whole basin) to 11049.7 km2 (36.2 %). We believe that although urbanization is the dominant factor contributing to the intensified imbalance trend (with a contribution of 71.2 %), influences from climate change also cannot be ignored (with a contribution of 28.8 %). Therefore, adaptation actions to climate change should be actively taken to reduce urban flood risks in the future. [ABSTRACT FROM AUTHOR]

Highlights • We proposed an improved method for vegetation cooling service assessment. • Vegetation coverage was used to discriminate the vegetation cooling ability. • The length of vegetation cooling service provision was defined. • A reasonable regional map of vegetation cooling service was derived. Abstract Quantitatively evaluating vegetation cooling service has become an important issue in current ecosystem service assessment, especially for urban area. Based on a previous method proposed on the energy exchanging theory, this study developed an improved method to generate a spatially explicit evaluation of the vegetation cooling service by introducing fractional vegetation cover (FVC) and the daily length of vegetation cooling service provision. Using remote sensing data from Landsat-8 and MODIS-Terra observations and field measurements from local meteorological stations, the method was successfully applied in Xiamen, a city located on the southeastern coast of China. The results showed that surface elevation and FVC had profound impacts on the length of vegetation cooling service provision and the vegetation cooling ability, respectively. For the vegetation surfaces of total 799.48 km2 in Xiamen, the annual heat absorption was 2.73 × 109 MJ/a in 2015 with an average length of cooling service provision of 1954.04 h. A more reasonable spatial distribution of vegetation heat absorbing capacity can be found with the differences not only among different vegetation types but also within the same vegetation type. Thus, this study emphasized the impacts of vegetation coverage and cooling length on providing cooling service, which has practical implications for vegetation planning in urban areas. [ABSTRACT FROM AUTHOR]

• Metacoupling framework can be used to comprehensively and systematically understand ecosystem service flows. • Our case study showed that the decrease in hydrological regulation flow toward distant systems was the most significant. • Grassland loss was the main reason for the decrease in hydrological regulation flow toward distant systems. • Distant systems can participate in the grassland protection of the upstream areas through scientific ecological compensation mechanisms. Ecosystem service (ES) flow is an indispensable link between natural ecosystem and socioeconomic system. Research on ES flow is of great significance for regional ecosystem management and ecological compensation policies. However, previous studies have mainly focused on ES flow within a region or ES flow across regions, without distinguishing the relationship between ES flow within a region and ES flow from the region to its external regions. Therefore, taking the Huangshui River Basin in the Tibetan Plateau as an example, we combined the revised equivalent factor method and the breaking point model to analyze the ES flow within the basin and ES flow between the basin and its external regions (including adjacent and distant systems) under the metacoupling framework. The results showed that ES flow within the basin, ES flow to adjacent systems and ES flow to distant systems decreased from 2000 to 2020. ES flow to distant systems decreased the most, with an average decrease of 666 million yuan. Moreover, among different ESs, the decrease in hydrological regulation flow to the distant system was the most substantial, at least 2.4 times that of other ESs. Grassland loss in the basin was the main reason for the decrease in hydrological regulation flow to distant systems. Therefore, we suggest that future ecosystem conservation in the basin needs the participation of distant systems to ensure the ESs provided to them. Following the basic principle of "who benefits, who compensates", distant systems that benefit can establish the grassland ecological compensation mechanisms to maintain the hydrological regulation service flowing to them, thereby ensuring water security and promoting sustainable development. [ABSTRACT FROM AUTHOR]

The rapid and timely evaluation of urban environmental change is highly important for understanding urban sustainability in China. However, the comprehensive understanding of urban environmental change in China based on multi-source remote sensing data remains inadequate because current studies have mainly focused on a single aspect of the urban environment using a specific source of remote sensing data. In this study, we developed a comprehensive evaluation index (CEI) combining the remote sensing data of the fine particulate matter (PM 2.5 ) concentration, land surface temperature (LST) and vegetation cover (VC) to assess the urban environmental change in China at the national scale, among urban agglomerations and across the rapidly urbanized regions. We found a trend of environmental degradation in the urban areas of China between 2000 and 2012. Environmentally degraded and moderately degraded urban areas accounted for 48.14% of the total urban area in China. In particular, the expanded urban areas exhibited the most extensive environmental degradation, with 52.33% of the total expanded urban areas from 1992 to 2012 exhibiting environmental degradation or moderately environmental degradation. The increase in the PM 2.5 concentration was one of the main manifestations of the environmental degradation in the expanded urban areas. We suggest that more attention should be paid to urban environmental issues during future urban development in China. [ABSTRACT FROM AUTHOR]

The timely and effective assessment of the impacts of urban expansion on regional carbon storage is an important issue in the fields of urban ecology and sustainability science. This study used a new model to assess the impacts of urban expansion on regional carbon storage by linking the LUSD-urban and InVEST models. First, the LUSD-urban model was used to simulate urban expansion. Then, the InVEST model was adopted to assess the impacts on regional carbon storage. The linked model combines the strengths of these two models. Not only can it simulate and project the process of urban expansion but it can also assess the impacts of urban expansion on regional carbon storage. A case study in Beijing showed that the relative error between the simulated carbon storage loss and the actual loss was less than 12%. We argue that the linked model can be applied to assess the ecological effects of future urban expansion. [ABSTRACT FROM AUTHOR]

Assessing the impact of climate change on urban landscape dynamics (ULD) is the foundation for adapting to climate change and maintaining urban landscape sustainability. This paper demonstrates an alternative future analysis by coupling a system dynamics (SD) and a cellular automata (CA) model. The potential impact of different climate change scenarios on ULD from 2009 to 2030 was simulated and evaluated in the Beijing–Tianjin–Tangshan megalopolis cluster area (BTT-MCA). The results suggested that the integrated model, which combines the advantages of the SD and CA model, has the strengths of spatial quantification and flexibility. Meanwhile, the results showed that the influence of climate change would become more severe over time. In 2030, the potential urban area affected by climate change will be 343.60–1260.66 km 2 (5.55 –20.37 % of the total urban area, projected by the no-climate-change-effect scenario). Therefore, the effects of climate change should not be neglected when designing and managing urban landscape. [ABSTRACT FROM AUTHOR]

• We evaluate the implementation and potential impact of solar energy-based poverty reduction program in Qinghai, China. • PV stations, precisely planned to fulfill 'targeted' intervention, were aggregated into larger PV farms in implementation. • It is challenging to precisely target the poor, improve income, facilitate energy transition, and enhance local capacity. • Future energy-based development needs to sufficiently consider local contexts and promote local engagement. In 2014, China initiated a nationwide poverty reduction campaign through deploying photovoltaic (PV) systems in its vast rural areas, which aims to support over 2 million households. Despite the significant socioeconomic benefits anticipated by policy-makers, it remains unclear regarding the challenges of implementing such an ambitious program in remote rural areas and its effect on poverty reduction. Focusing on Qinghai, a province that serves as the testbed for solar energy development in China but suffers chronic poverty, we aim to assess implementation status of the program, and examine whether and how solar energy-based development affects rural household well-being and generates socioeconomic spillovers. Using data from multiple sources, including household survey, interviews, policy documents, and large-scale socioeconomic covariates, as well as advanced statistical and spatial analyses, we find there have been substantial adjustments to the plan of building small-scale PV stations across poor villages throughout Qinghai. While total installation capacity was met, the 97 planned PV stations in 39 counties were aggregated into 24 medium- to large-scale PV farms in 27 counties. We also find substantial challenges to precisely target the poor, improve their income, facilitate a transition in household use of energy, and enhance local capacity for economic development. Future PV-based intervention programs need to sufficiently consider local contexts and demands, and promote local engagement to achieve the twin goals of sustainable energy transition and poverty reduction. [ABSTRACT FROM AUTHOR]

• We present a framework to evaluate the city-scale supply and demand of flood regulation services. • Multiple methods were applied to compare the supply and demand of the flood regulation services. • The flood regulation demand was relatively higher than the supply in 92 (or 32.86% of) catchments. • The insufficient supply can be solved through inter-catchment supply sharing from neighbors. • Concave green lands can enhance the flood regulation supply. In the context of climate change and rapid urbanization, pluvial flooding has posed an increasing challenge for urban sustainability and drawn research attention to better understanding the role of an ecosystem's flood regulation service (EFRS) in mitigating floods. However, relatively little is known about the supply and demand of the EFRS at the city scale and about the effect of nature-based solutions on the EFRS. To fill this gap, we present an integrated method to calculate the EFRS supply as the difference between precipitation and runoff using hydrology models and the EFRS demand as the expected flood damages through flood risk analysis. The spatial relationship between the supply and demand of the EFRS is analyzed using spatial statistics. A case study in central Shanghai, China, shows that the total EFRS demand is US$ 1.14 billion for a 100-year pluvial flood, with the demand density decreasing from the west to the east. The total EFRS supply is 2.14 × 107 m3, with the supply density increasing from the center and to the periphery. The EFRS supply and demand are imbalanced, as the demand is relatively higher than the supply in 92 (or 32.86%) catchments. Three of these imbalanced catchments can potentially be satisfied through inter-catchment EFRS sharing from neighboring catchments with abundant supplies of the EFRS. The number of imbalanced catchments can also be reduced to 27–42 by adopting concave green lands. The proposed methods have a broad application in other cities around the world. These findings could facilitate a comprehensive understanding of the EFRS at the city scale and help policy-makers formulate an integrated flood risk management strategy. [ABSTRACT FROM AUTHOR]

Rapid expansion of urban land areas in the past few decades has exerted great pressure on regional environment, and simulating urban land dynamics is of great significance for sustainable urban development. However, the differences in driving forces of urban land among cities were not fully considered in previous simulations. Here, we adopted a data-driven approach combined with Monte Carlo method to simulate future urban land quantity in China at the city scale under the Shared Socioeconomic Pathways (SSPs). The results show that the total urban land area of China will reach 154,105 to 289,932 km2 by 2070 under different scenarios, 1.8 to 3.4 times that of 2020. Compared with the traditional methods at the national or regional scale, the clustering method used to classify urban land expansion types can better fit the urban land change of each city. Meanwhile, the iterative simuation of future urban land quantity can depict the slowing down trend of urban land expansion. This study provides the amount of urban land from 2020 to 2070 at the city scale, confirming a close relationship between urban development and selection of urbanization pathway. Choosing a more sustainable path of social and economic development is conducive to restraining the rapid expansion of urban land in China. It is particularly important to formulate city-specific sustainable development strategies according to the trend of urban land dynamics over time. • We simulate urban land dynamics for 280 Chinese cities under the SSPs. • The data driven approach combined with Monte Carlo performed better than regional static models. • can evolve from a rapidly urbanizing one to a steadily urbanizing or an urbanized one over time. • We can simulate the slow down of urban land expansion after 2050s under SSP1. [ABSTRACT FROM AUTHOR]

Urban buildings and their three-dimensional (3D) morphologies play important roles in influencing urban climates and the diffusion of air pollutants. Previous studies on the 3D morphologies of urban buildings were mainly conducted within cities due to limited data, and we still lack an understanding of their features among cities, especially along urban-rural gradients. Here, we analyzed the urban-rural gradients of the 3D morphologies of buildings for 91 cities in China by using two groups of morphologic indicators and the concentric buffer method. Then, we used a hierarchical clustering method based on dynamic time warping to classify the gradients. Our results showed that >75 % of grids have a mean height of 9 m to 16 m, and their building coverage ranged from 20 % to 60 %. The gradients of five morphology indicators could be clustered to 9 patterns, and the dominant urban-rural gradient having the average height and building coverage decreasing over distance. This study provided a methodological framework for the quantitative analysis of the urban-rural gradient of the 3D morphologies of urban buildings, and can provide information on mitigate city-scale climate issues. • Two groups of aggregated indicators were used to examine 3D morphologies along urban-rural gradients. • The gradients of morphologies manifested as a declining trend of height and an increasing variation of height and building coverage. • The dynamic time warping can be used to conduct the clustering of series form data with different sizes. • The urban-rural gradients of morphologies can provide supplementary information on mitigate city-scale climate issues. [ABSTRACT FROM AUTHOR]

• We developed a method to assess the dynamics of flood regulation service (FRS). • The new method can ensure comparability across regions and over time. • Urban area proportion is strongly related to the supply–demand relationship of FRS. • The basin should control urban expansion and dredge lake for flood risk prevention. Recognizing changes in the supply–demand relationship of Flood Regulation Service (FRS) is significant for the rational planning of urban patterns and the prevention of flooding risks in river basins. Most existing studies have explored its spatial pattern but pay less attention to its spatiotemporal changes. This study explored the dynamic changes in the supply–demand relationship of FRS in rapidly urbanizing basins. We proposed the Supply-Demand Ratio (SDR) method, which used the Soil Conservation Service Curve Number (SCS-CN) model and the flood vulnerability index to quantify the supply and demand of FRS, and then, we calculated the SDR. Additionally, we calculated the rate of change in SDR from 1990 to 2018 in the basin and its subbasins. The case study in the Baiyangdian Lake Basin showed that the SDR method can effectively measure the changes in the relationship between the supply and demand of FRS in the river basin. The SDR was consistent with the supply–demand bivariate mapping method, with Kappa coefficients of 0.610 and 0.835 in 1990 and in 2018, respectively. Furthermore, we found that from 1990 to 2018, the imbalance of FRS in supply and demand intensified. The SDR for the whole basin decreased by 0.088 from 1990 to 2018, with a change rate of −27.8%. Rapid urbanization is an important reason for intensification of the FRS supply–demand imbalance. The proportion of urban area is the most relevant factor for the supply–demand relationship of FRS, with a Pearson correlation coefficient of −0.845 (p < 0.01). Therefore, we suggest that proactive policies be adopted to defend against flood disaster risks in the future construction of the Xiong'an New Area, which is located downstream from the Baiyangdian Lake Basin. [ABSTRACT FROM AUTHOR]

The shrinking of cities has become an increasingly global phenomenon, posing challenges for sustainable urban development. However, most focus remains on Europe and North America, and relatively little attention has been paid to the East Asia, especially the urbanizing China. Nighttime light (NL) dataset and its features (long-term time-series free access and large coverage) provide an alternative means to quantify shrinking cities. Here, we developed a new approach to identify shrinking cities and measure urban shrinkage, using corrected-integrated DMSP/OLS and NPP/VIIRS NL data. Based on this approach, we quantified the spatiotemporal patterns of shrinking cities in China from 1992 to 2019. Our study identified 153 shrinking cities in China during the study period, accounting for 23.39% of all 654 cities. These shrinking cities were widely distributed across eight economic regions and most provinces. The number of shrinking cities changed periodically and peaked following the Asian Financial Crisis in 1997 and again after the Global Economic Crisis in 2008. The cities that experienced the greatest shrinkage intensity were mainly distributed in northeast China, with severe urban shrinkage occurring between 2008 and 2013. The new approach proposed in this study can effectively identify shrinking city hotspots and key periods of urban shrinkage. Our findings suggest that sustainable urban development in China must consider shrinking cities, which are faced with challenging and urgent sustainability issues different from those by rapidly growing cities. • We proposed a method to quantify shrinking cities using two nighttime-light data. • About 23% of Chinese cities were identified as shrinking cities from 1992 to 2019. • Shrinking cities were widespread in all economic regions and most provinces. • Shrinking cities increased periodically and peaked after financial/economic crises. • The most severe urban shrinkage occurred in northeast China between 2008 and 2013. [ABSTRACT FROM AUTHOR]

[Display omitted] • EFRS (ecosystem's flood regulation service) demand varies across different return periods; • Multiple return periods are included in a new framework to estimate the expected annual EFRSs; • The measurement units of EFRS supply and demand are unified and comparable; • Upstream supplies can alleviate the unsatisfication, implying a catchment EFRS management; • Priority areas for EFRS management are identified as being unsatisfied and relatively populous. An ecosystem's flood regulation service (EFRS) is important for alleviating flood risk. Both the EFRS and the relationship between EFRS supply and demand may change across flood return periods. However, most studies only considered the EFRS under a single flood return period. In this regard, a new framework is proposed that integrates multiple flood return periods to assess the expected annual EFRS supply and demand. It also considers the upstream EFRS supply flowing from the headwaters toward the downstream. A case study in the Yangtze River Basin, China, shows that the EFRS demand increases dramatically from 25- to 200-year return periods, while the EFRS supplies remain relatively constant. In terms of the expected annual EFRSs that integrate the four return-period EFRS demands and local supplies, 47 (or 43.12%) sub-basins are found to be unsatisfied (the demand is larger than the supply). This number could be reduced to 17 (or 15.60%) sub-basins if the upstream EFRS supply is considered in comparing the EFRS supply and demand, implying the importance of a catchment-wide EFRS management, particularly protecting the upstream forests, rivers and lakes, grasslands, as well as properly regulating the dams. The proposed framework could be readily applied in other basins and shed light on a comprehensive understanding and management of the EFRSs. [ABSTRACT FROM AUTHOR]

As an alternative to conventional liquid fuels, bioethanol holds the promise of transitioning to a clean and low-carbon energy future. China's bioethanol industry is at its nascent stage. In this study, we developed a hybrid life cycle assessment model that integrates the multi-regional input-output (MRIO) approach and specific production data to evaluate the social, economic, and environmental (i.e. the triple-bottom-line, TBL) impacts of the bioethanol sector in China's economic systems. The MRIO model was constructed using the 2012 MRIO table, and the data for the typical technologies of bioethanol production were leveraged. To be specific, we evaluated employment creation, economic stimulus, and energy use of bioethanol production in 28 scenarios in Henan province. The results show that compared to petroleum refining, bioethanol production is more effective for economic stimulus and energy saving, but less effective at job creation. The impact of bioethanol production varies by technologies. For every 1 million yuan of bioethanol production in China' economic system, first-generation technology offers a projected 1.92 million yuan in economic growth and job creation of 2.06 full-time equivalent, while the second-generation technology offers a lower energy consumption (1.19 TJ). In most scenarios, the upstream sectors account for more than half of the TBL impacts of biofuel production. This study helps to quantify the TBL impacts associated with the gasoline-to-bioethanol transition in China, envisions the green opportunities for impact mitigation, and sheds light on the potential direction for robust planning and policy making to advance the bioethanol industry's development. • A MRIO-based hybrid LCA was undertaken for bioethanol production in China. • Employment, economic stimulus and energy use were assessed for bioethanol production. • Bioethanol is more effective on energy saving and economic stimulus than gasoline. • Second-generation bioethanol has the highest energy return on investment value. • Supply-chain sectors make up the majority of social and environmental impacts. [ABSTRACT FROM AUTHOR]