Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the bu...Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the built-up region within the Fifth Ring Road of Beijing was selected as the study area. The details of land cover and urban function zones(UFZs) were identified using GIS and RS methods. On this basis, the SCS-CN model was adopted to analyze the rainfall-runoff risk characteristics of the study area. The results showed that:(1) UFZs within different levels of runoff risk varied under different rainfall conditions. The area ratio of the UFZs with high runoff risk increased from 18.90%(for rainfall return period of 1 a) to 54.74%(for period of 100 a). Specifically, urban commercial areas tended to have the highest runoff risk, while urban greening spaces had the lowest.(2) The spatial characteristics of the runoff risks showed an obvious circular distribution. Spatial cluster areas with high runoff risk were mainly concentrated in the center of the study area, while those with low runoff risk were mainly distributed between the fourth and fifth ring roads. The results indicated that the spatial clustering characteristic of urban runoff risk and runoff heterogeneity among different UFZs should be fully considered during urban rainwater management.展开更多
To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limit...To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limitations of existing thermal vulnerability assessments by incorporating human perception into the analysis.Specifically,we introduce the sky openness index to reflect human perception of the thermal environment and examine variations in thermal vulnerability across different UFZs.Using the Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)model,we analyze the contributions of 2D and 3D urban form indicators to thermal vulnerability and link these contributions to the unique needs and vulnerability characteristics of UFZs of Foshan City,China in 2023.The results reveal that:1)high-value heat-fragile areas(1.74–2.00]constitute 10.42%of Foshan City;2)traffic zone and publiccommercial zone exhibit the highest levels of thermal vulnerability;and 3)building height and the normalized building index are the most influential factors,with contributions of|0.06|and|0.03|,respectively.We provide a scientific foundation for developing governance strategies to promote urban resilience.展开更多
Large-scale urban land expansion in mountainous and hilly areas(UEMH)has significantly altered the terrain in many Chinese cities,leading to various environmental and urban challenges.Despite its importance,there is l...Large-scale urban land expansion in mountainous and hilly areas(UEMH)has significantly altered the terrain in many Chinese cities,leading to various environmental and urban challenges.Despite its importance,there is limited nation-scale research that reveals the amount and the spatial variations of UEMH-induced terrain alteration.This research integrates the Global Annual Urban Dynamics dataset,the Global Basic Landform Unit dataset,the TanDEM-X DEM Change Map(DCM)dataset,Baidu Points-of-Interest(POI),and other auxiliary datasets to conduct a comprehensive analysis of terrain alteration induced by UEMH in China from 2012 to 2020.The results indicate that the country-wide UEMH-induced terrain alteration reached approximately 13 billion m^(3),which is about 100 times the volume of Hangzhou West Lake,and terrain alteration volume in over 300 counties exceeded 10 million m^(3).The Southwest and Southeast regions,which are ecologically sensitive and critical,feature the greatest alteration in terms of area and volume.The most significant terrain alteration in terms of intensity is observed in the Southwest and Hengduan Mountain Area.Additionally,there are significant spatial variations in the contributions of different urban functional zones to terrain alteration.Our findings indicate that urban land expansion in mountains and hills has significantly altered terrain in some regions of China,necessitating customized urban planning strategies for better managing mountainous urban land expansion and governance policies to address the geological,ecological,and urban development challenges.展开更多
Functional zones in cities constitute the most conspicuous components of newly developed urban areas, and have been a hot spot for domestic and foreign investors in China, which not only show the expanse of urban spac...Functional zones in cities constitute the most conspicuous components of newly developed urban areas, and have been a hot spot for domestic and foreign investors in China, which not only show the expanse of urban space accompanied by the shifts both in landscape (from rural to urban) and land use(from less extensive to extensive), but also display the transformation of regional ecological functions. By using the theories and methods of landscape ecology, the structure of landscapes and landscape ecological planning can be analyzed and evaluated for studying the urban functional zones' layout. In 1990, the Central Government of China declared to develop and open up Pudong New Area so as to promote economic development in Shanghai. Benefited from the advantages of Shanghai's location and economy, the government of Pudong New Area has successively built up 7 different functional zones over the past decade according to their functions and strategic goals. Based on the multi-spectral satellite imageries taken in 1990, 1997 and 2000, a landscape ecology analysis was carried out for Pudong New Area of Shanghai, supported by GIS technology. Green space (including croplands) and built-up areas are the major factors considered in developing urban landscape. This paper was mainly concerned with the different spatial patterns and dynamics of green space, built-up areas and new buildings in different functional zones, as influenced by different functional layouts and development strategies. The rapid urbanization in Pudong New Area resulted in a more homogeneous landscape. Agricultural landscape and suburban landscape were gradually replaced by urban landscape as the degree of urbanization increased. As a consequence of urbanization in Pudong, not only built-up patches, but also newly-built patches and green patches merged into one large patch, which should be attributed to the construction policy of extensive green space as the urban development process in Pudong New Area. The shape of green area of 7 functional zones became more and more regular because of the horticultural needs in Shanghai urban planning. Some suggestions were finally made for the study of future urban planning and layout.展开更多
Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and s...Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and socioeconomic databases of the counties in Beijing–Tianjin–Hebei region, this paper comprehensively calculates the environmental stress index(ESI) for the urban agglomeration using the entropy weight method(EWM) at the county scale and analyzes the spatiotemporal patterns and the differences among the four types of major functional zones(MFZ) for the period 2012–2016. In addition, the socioeconomic driving forces of environmental stress are quantitatively estimated using the geographically weighted regression(GWR) method based on the STIRPAT model framework. The results show that:(1) The level of environmental stress in the Beijing–Tianjin–Hebei region was significantly alleviated during that time period, with a decrease in ESI of 54.68% by 2016. This decrease was most significant in Beijing, Tangshan, Tianjin, Shijiazhuang, and other central urban areas, as well as the Binhai New Area. The level of environmental stress in counties decreased gradually from the central urban areas to the suburban areas, and the high-level stress counties were eliminated by 2016.(2) The spatial spillover effect of environmental stress increased further at the county scale from 2012 to 2016, and spatial locking and path dependence emerged in the cities of Tangshan and Tianjin.(3) Urbanized zones(development-optimized and development-prioritized zones) were the major areas bearing environmental pollution in the Beijing–Tianjin–Hebei region in that time period. The ESI accounted for 65.98% of the whole region, where there was a need to focus on the prevention and control of environmental pollution.(4) The driving factors of environmental stress at the county scale included population size and the level of economic development. In addition, the technical capacity of environmental waste disposal, the intensity of agricultural production input, the intensity of territorial development, and the level of urbanization also had a certain degree of influence.(5) There was spatial heterogeneity in the effects of the various driving factors on the level of environmental stress. Thus, it was necessary to adopt differentiated environmental governance and reduction countermeasures in respect of emission sources, according to the intensity and spatiotemporal differences in the driving forces in order to improve the accuracy and adaptability of environmental collaborative control in the Beijing–Tianjin–Hebei region.展开更多
随着低空经济发展,无人机配送与城市空间协同日益密切。为探究其发展现状,首先以Web of Science为数据库检索相关文献并进行关键词共现与聚类分析。结果表明,当前研究正呈现从单一技术应用向“技术―空间”协同转型的趋势。通过梳理无...随着低空经济发展,无人机配送与城市空间协同日益密切。为探究其发展现状,首先以Web of Science为数据库检索相关文献并进行关键词共现与聚类分析。结果表明,当前研究正呈现从单一技术应用向“技术―空间”协同转型的趋势。通过梳理无人机配送与城市空域规划、社会接受度的关联机制,构建协同框架,并将城市按空间特征、配送需求及社会敏感度划分为6类功能区,针对性提出策略:商业区空域分层管控+屋顶物流节点;住宅区分时段禁飞+低空配送走廊;生态敏感区全域禁飞+应急限高;工业区模块化停机坪;混合功能区航路分时复用。研究旨在推动无人机配送与城市空间深度融合,为低空经济可持续发展提供理论支撑与实践路径。展开更多
城市功能区识别可为城市建设决策提供技术支撑。本研究提出了面向城市功能区识别的多源场景特征Transformer融合方法。利用路网构建交通分析区(Traffic Analysis Zone,TAZ),采用Delaunay三角网创建POI(Point of Interest)数据的图结构,...城市功能区识别可为城市建设决策提供技术支撑。本研究提出了面向城市功能区识别的多源场景特征Transformer融合方法。利用路网构建交通分析区(Traffic Analysis Zone,TAZ),采用Delaunay三角网创建POI(Point of Interest)数据的图结构,通过TAZ获得遥感数据的影像对象;利用图卷积网络提取POI图结构的社会场景特征,由ResNet-50编码遥感数据的自然场景特征;基于Transformer的多头注意力机制融合多维特征,依托SoftMax实现功能区识别。以沈阳市主城区为例,以2021年的OpenStreetMap、POI和遥感数据为数据源。该方法的总体精度和Kappa系数为82.2%和70%,Kappa系数较单一数据方法和其他融合方法至少提高18%和9%。本研究采用Transformer融合社会场景特征和自然场景特征,解决了多源数据难以集成表达的问题,为城市功能区识别提供了新的技术路径。展开更多
基金Major Program of National Natural Science Foundation of China,No.41590841Key Project for National Natural Science Foundation of China,No.41230633
文摘Urbanization significantly increases the risk of urban flooding. Therefore, quantitative study of urban rainfall-runoff processes can provide a scientific basis for urban planning and management. In this paper, the built-up region within the Fifth Ring Road of Beijing was selected as the study area. The details of land cover and urban function zones(UFZs) were identified using GIS and RS methods. On this basis, the SCS-CN model was adopted to analyze the rainfall-runoff risk characteristics of the study area. The results showed that:(1) UFZs within different levels of runoff risk varied under different rainfall conditions. The area ratio of the UFZs with high runoff risk increased from 18.90%(for rainfall return period of 1 a) to 54.74%(for period of 100 a). Specifically, urban commercial areas tended to have the highest runoff risk, while urban greening spaces had the lowest.(2) The spatial characteristics of the runoff risks showed an obvious circular distribution. Spatial cluster areas with high runoff risk were mainly concentrated in the center of the study area, while those with low runoff risk were mainly distributed between the fourth and fifth ring roads. The results indicated that the spatial clustering characteristic of urban runoff risk and runoff heterogeneity among different UFZs should be fully considered during urban rainwater management.
基金Under the auspices of Liaoning Revitalization Talents Program(No.XLYC2202024)Basic Scientific Research Project(Key Project)of the Education Department of Liaoning Province(No.LJ212410165084)the Fundamental Research Funds for the Central Universities(No.N2111003,N2411001)。
文摘To adapt to national climate change strategies,understanding the thermal vulnerability of urban functional zones(UFZs)is critical for enhancing the livability and sustainable development of cities.We address the limitations of existing thermal vulnerability assessments by incorporating human perception into the analysis.Specifically,we introduce the sky openness index to reflect human perception of the thermal environment and examine variations in thermal vulnerability across different UFZs.Using the Extreme Gradient Boosting(XGBoost)-SHapley Additive exPlanations(SHAP)model,we analyze the contributions of 2D and 3D urban form indicators to thermal vulnerability and link these contributions to the unique needs and vulnerability characteristics of UFZs of Foshan City,China in 2023.The results reveal that:1)high-value heat-fragile areas(1.74–2.00]constitute 10.42%of Foshan City;2)traffic zone and publiccommercial zone exhibit the highest levels of thermal vulnerability;and 3)building height and the normalized building index are the most influential factors,with contributions of|0.06|and|0.03|,respectively.We provide a scientific foundation for developing governance strategies to promote urban resilience.
基金supported by the National Natural Science Foundation of China(Grants No.42322110 and 42271415)。
文摘Large-scale urban land expansion in mountainous and hilly areas(UEMH)has significantly altered the terrain in many Chinese cities,leading to various environmental and urban challenges.Despite its importance,there is limited nation-scale research that reveals the amount and the spatial variations of UEMH-induced terrain alteration.This research integrates the Global Annual Urban Dynamics dataset,the Global Basic Landform Unit dataset,the TanDEM-X DEM Change Map(DCM)dataset,Baidu Points-of-Interest(POI),and other auxiliary datasets to conduct a comprehensive analysis of terrain alteration induced by UEMH in China from 2012 to 2020.The results indicate that the country-wide UEMH-induced terrain alteration reached approximately 13 billion m^(3),which is about 100 times the volume of Hangzhou West Lake,and terrain alteration volume in over 300 counties exceeded 10 million m^(3).The Southwest and Southeast regions,which are ecologically sensitive and critical,feature the greatest alteration in terms of area and volume.The most significant terrain alteration in terms of intensity is observed in the Southwest and Hengduan Mountain Area.Additionally,there are significant spatial variations in the contributions of different urban functional zones to terrain alteration.Our findings indicate that urban land expansion in mountains and hills has significantly altered terrain in some regions of China,necessitating customized urban planning strategies for better managing mountainous urban land expansion and governance policies to address the geological,ecological,and urban development challenges.
文摘Functional zones in cities constitute the most conspicuous components of newly developed urban areas, and have been a hot spot for domestic and foreign investors in China, which not only show the expanse of urban space accompanied by the shifts both in landscape (from rural to urban) and land use(from less extensive to extensive), but also display the transformation of regional ecological functions. By using the theories and methods of landscape ecology, the structure of landscapes and landscape ecological planning can be analyzed and evaluated for studying the urban functional zones' layout. In 1990, the Central Government of China declared to develop and open up Pudong New Area so as to promote economic development in Shanghai. Benefited from the advantages of Shanghai's location and economy, the government of Pudong New Area has successively built up 7 different functional zones over the past decade according to their functions and strategic goals. Based on the multi-spectral satellite imageries taken in 1990, 1997 and 2000, a landscape ecology analysis was carried out for Pudong New Area of Shanghai, supported by GIS technology. Green space (including croplands) and built-up areas are the major factors considered in developing urban landscape. This paper was mainly concerned with the different spatial patterns and dynamics of green space, built-up areas and new buildings in different functional zones, as influenced by different functional layouts and development strategies. The rapid urbanization in Pudong New Area resulted in a more homogeneous landscape. Agricultural landscape and suburban landscape were gradually replaced by urban landscape as the degree of urbanization increased. As a consequence of urbanization in Pudong, not only built-up patches, but also newly-built patches and green patches merged into one large patch, which should be attributed to the construction policy of extensive green space as the urban development process in Pudong New Area. The shape of green area of 7 functional zones became more and more regular because of the horticultural needs in Shanghai urban planning. Some suggestions were finally made for the study of future urban planning and layout.
基金National Natural Science Foundation of China,No.41971164, No.42071148Strategic Priority Research Program of the Chinese Academy of Sciences,Grant No.XDA23020101。
文摘Environmental stress is used as an indicator of the overall pressure on regional environmental systems caused by the output of various pollutants as a result of human activities. Based on the pollutant emissions and socioeconomic databases of the counties in Beijing–Tianjin–Hebei region, this paper comprehensively calculates the environmental stress index(ESI) for the urban agglomeration using the entropy weight method(EWM) at the county scale and analyzes the spatiotemporal patterns and the differences among the four types of major functional zones(MFZ) for the period 2012–2016. In addition, the socioeconomic driving forces of environmental stress are quantitatively estimated using the geographically weighted regression(GWR) method based on the STIRPAT model framework. The results show that:(1) The level of environmental stress in the Beijing–Tianjin–Hebei region was significantly alleviated during that time period, with a decrease in ESI of 54.68% by 2016. This decrease was most significant in Beijing, Tangshan, Tianjin, Shijiazhuang, and other central urban areas, as well as the Binhai New Area. The level of environmental stress in counties decreased gradually from the central urban areas to the suburban areas, and the high-level stress counties were eliminated by 2016.(2) The spatial spillover effect of environmental stress increased further at the county scale from 2012 to 2016, and spatial locking and path dependence emerged in the cities of Tangshan and Tianjin.(3) Urbanized zones(development-optimized and development-prioritized zones) were the major areas bearing environmental pollution in the Beijing–Tianjin–Hebei region in that time period. The ESI accounted for 65.98% of the whole region, where there was a need to focus on the prevention and control of environmental pollution.(4) The driving factors of environmental stress at the county scale included population size and the level of economic development. In addition, the technical capacity of environmental waste disposal, the intensity of agricultural production input, the intensity of territorial development, and the level of urbanization also had a certain degree of influence.(5) There was spatial heterogeneity in the effects of the various driving factors on the level of environmental stress. Thus, it was necessary to adopt differentiated environmental governance and reduction countermeasures in respect of emission sources, according to the intensity and spatiotemporal differences in the driving forces in order to improve the accuracy and adaptability of environmental collaborative control in the Beijing–Tianjin–Hebei region.
文摘随着低空经济发展,无人机配送与城市空间协同日益密切。为探究其发展现状,首先以Web of Science为数据库检索相关文献并进行关键词共现与聚类分析。结果表明,当前研究正呈现从单一技术应用向“技术―空间”协同转型的趋势。通过梳理无人机配送与城市空域规划、社会接受度的关联机制,构建协同框架,并将城市按空间特征、配送需求及社会敏感度划分为6类功能区,针对性提出策略:商业区空域分层管控+屋顶物流节点;住宅区分时段禁飞+低空配送走廊;生态敏感区全域禁飞+应急限高;工业区模块化停机坪;混合功能区航路分时复用。研究旨在推动无人机配送与城市空间深度融合,为低空经济可持续发展提供理论支撑与实践路径。
文摘城市功能区识别可为城市建设决策提供技术支撑。本研究提出了面向城市功能区识别的多源场景特征Transformer融合方法。利用路网构建交通分析区(Traffic Analysis Zone,TAZ),采用Delaunay三角网创建POI(Point of Interest)数据的图结构,通过TAZ获得遥感数据的影像对象;利用图卷积网络提取POI图结构的社会场景特征,由ResNet-50编码遥感数据的自然场景特征;基于Transformer的多头注意力机制融合多维特征,依托SoftMax实现功能区识别。以沈阳市主城区为例,以2021年的OpenStreetMap、POI和遥感数据为数据源。该方法的总体精度和Kappa系数为82.2%和70%,Kappa系数较单一数据方法和其他融合方法至少提高18%和9%。本研究采用Transformer融合社会场景特征和自然场景特征,解决了多源数据难以集成表达的问题,为城市功能区识别提供了新的技术路径。
