Urban land provides a suitable location for various economic activities which affect the development of surrounding areas. With rapid industrialization and urbanization, the contradictions in land-use become more noti...Urban land provides a suitable location for various economic activities which affect the development of surrounding areas. With rapid industrialization and urbanization, the contradictions in land-use become more noticeable. Urban administrators and decision-makers seek modern methods and technology to provide information support for urban growth. Recently, with the fast development of high-resolution sensor technology, more relevant data can be obtained, which is an advantage in studying the sustainable development of urban land-use. However, these data are only information sources and are a mixture of "information" and "noise". Processing, analysis and information extraction from remote sensing data is necessary to provide useful information. This paper extracts urban land-use information from a high-resolution image by using the multi-feature information of the image objects, and adopts an object-oriented image analysis approach and multi-scale image segmentation technology. A classification and extraction model is set up based on the multi-features of the image objects, in order to contribute to information for reasonable planning and effective management. This new image analysis approach offers a satisfactory solution for extracting information quickly and efficiently.展开更多
Spatial and temporal informationon urban infrastructure is essential and requires various land-cover/land-use planning and management applications.Besides,a change in infrastructure has a direct impact on other land-c...Spatial and temporal informationon urban infrastructure is essential and requires various land-cover/land-use planning and management applications.Besides,a change in infrastructure has a direct impact on other land-cover and climatic conditions.This study assessed changes in the rate and spatial distribution of Peshawar district’s infrastructure and its effects on Land Surface Temperature(LST)during the years 1996 and 2019.For this purpose,firstly,satellite images of bands7 and 8 ETM+(Enhanced Thematic Mapper)plus and OLI(Operational Land Imager)of 30 m resolution were taken.Secondly,for classification and image processing,remote sensing(RS)applications ENVI(Environment for Visualising Images)and GIS(Geographic Information System)were used.Thirdly,for better visualization and more in-depth analysis of land sat images,pre-processing techniques were employed.For Land use and Land cover(LU/LC)four types of land cover areas were identified-vegetation area,water cover,urbanized area,and infertile land for the years under research.The composition of red,green,and near infra-red bands was used for supervised classification.Classified images were extracted for analyzing the relative infrastructure change.A comparative analysis for the classification of images is performed for SVM(Support Vector Machine)and ANN(Artificial Neural Network).Based on analyzing these images,the result shows the rise in the average temperature from 30.04℃ to 45.25℃.This only possible reason is the increase in the built-up area from 78.73 to 332.78 Area km^(2) from 1996 to 2019.It has also been witnessed that the city’s sides are hotter than the city’s center due to the barren land on the borders.展开更多
Land cover classification is one of the main components of the modern weather research and forecasting models, which can influence the meteorological variable, and in turn the concentration of air pollutants. In this ...Land cover classification is one of the main components of the modern weather research and forecasting models, which can influence the meteorological variable, and in turn the concentration of air pollutants. In this study the impact of using two traditional land use classifications, the United States Geological Survey (USGS) and the Moderate-resolution Imaging Spectroradiometer (MODIS), were evaluated. The Weather Research and Forecasting model (WRF, version 3.2.1) was run for the period 18 - 22 August, 2014 (dry season) at a grid spacing of 3 km centered on the city of Manaus. The comparison between simulated and ground-based observed data revealed significant differences in the meteorological fields, for instance, the temperature. Compared to USGS, MODIS classification showed better skill in representing observed temperature for urban areas of Manaus, while the two files showed similar results for nearby areas. The analysis of the files suggests that the better quality of the simulations favorable to the MODIS file is straightly related to its better representation of urban class of land use, which is observed to be not adequately represented by USGS.展开更多
Urban planning construction land standard is the technical specification for scientifically allocating various types of urban construction land,and it is the basis for drawing up and revising the overall urban plannin...Urban planning construction land standard is the technical specification for scientifically allocating various types of urban construction land,and it is the basis for drawing up and revising the overall urban planning scheme.Considering China’s current urban planning construction land standard,many problems exist,such as the gap in the land use control threshold,the lack of regional differences in the climate revision,and failing to consider the topographic factors.To resolve these problems,this study proposed a step-by-step process framework and quantitative calculation method for the establishment and revision of standards in accordance with the principle of Total-Structure control.By setting the conditions,a universal basic standard for construction land was established.Quantitative analysis was then conducted on the relationship between the basic standard and the selected key indicators,such as urban population size,sunshine spacing coefficient,the width of river valleys or inter-montane basins,and terrain slope,among others.Finally,revised standards were formed for climate conditions,topography,and geomorphologic conditions,which were matched with the basic standards.The key results are three-fold:(1)The per capita construction land standard of 95 m~2/person can be used as the total indicator of China’s urban planning basic standard,and the corresponding per capita single construction land comprises 32.50%of residential land,7.42%of public management and public service land,22.50%of industrial land,17.50%of transportation facilities,12.50%of green space,and 7.58%of other land-use types.The results of the revision of the urban population size indicate that the difference in population size has little effect on the total amount of per capita construction land.(2)The climate revision results of per capita residential land and per capita construction land in major cities reveal that the revised climate value varies greatly between north and south China.The revised climate values of the per capita area of construction land vary by latitude as follows:the value at 20°N is 93 m^(2)/person,the value at 30°N is 97 m^(2)/person,the value at 40°N is 103 m^(2)/person,and the value at 50°N is 115 m^(2)/person.The basic standard land value of 95 m^(2)/person is generally distributed across the Xiamen-Guilin-Kunming line.(3)The cities located in mountainous areas,hilly valleys,or inter-montane basins can reduce the allocation of community parks and comprehensive parks when the average width of an existing river valley or inter-montane basin is less than 2 km.When the average width of the valley or inter-montane basin is between 2 km to 4 km,the allocation of the comprehensive parks can be reduced.The revised results of per capita sloping construction land reveal that the terrain slope greatly affects the revised value of per capita construction land.Specifically,the revised value at 3°is 3.68%higher than the basic standard value,and the increase rates at 8°,15°,and 25°are 11.25%,26.49%,and 68.47%,respectively.展开更多
This paper examines the utility of high-resolution airborne RGB orthophotos and LiDAR data for mapping residential land uses within the spatial limits of suburb of Athens, Greece. Modem remote sensors deliver ample in...This paper examines the utility of high-resolution airborne RGB orthophotos and LiDAR data for mapping residential land uses within the spatial limits of suburb of Athens, Greece. Modem remote sensors deliver ample information from the AOI (area of interest) for the estimation of 2D indicators or with the inclusion of elevation data 3D indicators for the classification of urban land. In this research, two of these indicators, BCR (building coverage ratio) and FAR (floor area ratio) are automatically evaluated. In the pre-processing step, the low resolution elevation data are fused with the high resolution optical data through a mean-shift based discontinuity preserving smoothing algorithm. The outcome is an nDSM (normalized digital surface model) comprised of upsampled elevation data with considerable improvement regarding region filling and "straightness" of elevation discontinuities. Following this step, a MFNN (multilayer feedforward neural network) is used to classify all pixels of the AOI into building or non-building categories. The information derived from the BCR and FAR building indicators, adapted to landscape characteristics of the test area is used to propose two new indices and an automatic post-classification based on the density of buildings.展开更多
The classification of urban functional areas plays an important role in urban planning and resource management.Although previous studies have confirmed that different urban func-tional areas have different morphologic...The classification of urban functional areas plays an important role in urban planning and resource management.Although previous studies have confirmed that different urban func-tional areas have different morphological structures and Land Surface Temperature(LST)characteristics,these two types of characteristics have rarely been fully integrated and used for functional area classification.In this paper,a new framework for classifying urban functional areas is proposed by combining urban morphological features and LST features.First,metrics are constructed from three levels,namely,building,road and region,which are used to portray urban morphology;LST is retrieved using thermal infrared remote sensing to reflect LST features with four metrics:the average temperature,maximum temperature,temperature difference and standard deviation of temperature.Then,the functional areas are classified into four categories:service/public land,commercial land,residential land and industrial land.A random forest algorithm is used to effectively fuse the features of these two categories and classify the functional areas.The effectiveness of the proposed framework is tested in the study area of Shenzhen City,Guangdong Province.The results show that the combined classification accuracy of the proposed classification method is 0.85,which is 0.26 higher than that of the classification model based on urban morphology and 0.1 higher than that of the classification model based on LST features.The proposed framework verifies that the integration of LST features into urban functional area classification is reliable and effectively combines urban morphology and LST features for functional area classification.展开更多
Homeowners’Associations(HOAs)dictate landscape structure and management through legally enforceable land covenants at the neighborhood scale in the USA.Determining the location and spatial extent of HOAs is critical ...Homeowners’Associations(HOAs)dictate landscape structure and management through legally enforceable land covenants at the neighborhood scale in the USA.Determining the location and spatial extent of HOAs is critical for examining its influence.However,such analysis is confounded by the lack of spatial data at the appropriate unit for such analysis.The purpose of this paper is to develop and realize an open source implementation to automate land parcel classification,which is an initial step towards the goal of determining the impact of HOAs on urban land management.Using Maricopa County,Arizona as a testbed,we found that parcel merging processes reduce the number of subdivisions from 26,042 to 17,269,such that boundaries better align with neighborhood units to which rule sets like land covenants apply.Moreover,after an initial training period,this process was completed in just over 7 hours.This research is an important first step in enabling a number of analysis including determining the location and spatial extent of HOAs regionally and,eventually,nationally and determining proposed links between HOAs and land management outcomes.展开更多
Urban land use information that reflects socio-economic functions and human activities is critically essential for urban planning,land-scape design,environmental management,health promotion,and biodiversity conservati...Urban land use information that reflects socio-economic functions and human activities is critically essential for urban planning,land-scape design,environmental management,health promotion,and biodiversity conservation.Land-use maps outlining the distribution,pattern,and composition of essential urban land use categories(EULUC)have facilitated a wide spectrum of applications and further triggered new opportunities in urban studies.New and improved Earth observations,algorithms,and advanced products for extracting thematic urban information,in association with emer-ging social sensing big data and auxiliary crowdsourcing datasets,all together offer great potentials to mapping fine-resolution EULUC from regional to global scales.Here we review the advances of EULUC mapping research and practices in terms of their data,methods,and applications.Based on the historical retrospect,we summarize the challenges and limitations of current EULUC studies regarding sample collection,mixed land use problem,data and model generalization,and large-scale mapping efforts.Finally,we propose and discuss future opportunities,including cross-scale mapping,optimal integration of multi-source features,global sam-ple libraries from crowdsourcing approaches,advanced machine learning and ensembled classification strategy,open portals for data visualization and sharing,multi-temporal mapping of EULUC change,and implications in urban environmental studies,to facil-itate multi-scale fine-resolution EULUC mapping research.展开更多
Landsat ETM/TM data and an artificial neural network (ANN) were applied to analyse the expansion of the city of Xi'an and land use/cover change of its surrounding area between 2000 and 2003. Supervised classificati...Landsat ETM/TM data and an artificial neural network (ANN) were applied to analyse the expansion of the city of Xi'an and land use/cover change of its surrounding area between 2000 and 2003. Supervised classification and normalized difference barren index (NDBI) were used respectively to retrieve its urban boundary. Results showed that the urban area increased by an annual rate of 12.3%, with area expansion from 253.37 km^2 in 2000 to 358.60 km^2 in 2003. Large areas of farmland in the north and southwest were converted into urban construction land. The land use/cover changes of Xi'an were mainly caused by fast development of urban economy, population immigration from countryside, great development of infrastructure such as transportation, and huge demands for urban market. In addition, affected by the government policy of “returning farmland to woodland”, some farmland was converted into economic woodland, such as Chinese goosebeerv garden, vineyard etc.展开更多
Background:Cities are social-ecological systems characterized by remarkably high spatial and temporal heterogeneity,which are closely related to myriad urban problems.However,the tools to map and quantify this heterog...Background:Cities are social-ecological systems characterized by remarkably high spatial and temporal heterogeneity,which are closely related to myriad urban problems.However,the tools to map and quantify this heterogeneity are lacking.We here developed a new three-level classification scheme,by considering ecosystem types(level 1),urban function zones(level 2),and land cover elements(level 3),to map and quantify the hierarchical spatial heterogeneity of urban landscapes.Methods:We applied the scheme using an object-based approach for classification using very high spatial resolution imagery and a vector layer of building location and characteristics.We used a top-down classification procedure by conducting the classification in the order of ecosystem types,function zones,and land cover elements.The classification of the lower level was based on the results of the higher level.We used an objectbased methodology to carry out the three-level classification.Results:We found that the urban ecosystem type accounted for 45.3%of the land within the Shenzhen city administrative boundary.Within the urban ecosystem type,residential and industrial zones were the main zones,accounting for 38.4%and 33.8%,respectively.Tree canopy was the dominant element in Shenzhen city,accounting for 55.6%over all ecosystem types,which includes agricultural and forest.However,in the urban ecosystem type,the proportion of tree canopy was only 22.6%because most trees were distributed in the forest ecosystem type.The proportion of trees was 23.2% in industrial zones,2.2%higher than that in residential zones.That information“hidden”in the usual statistical summaries scaled to the entire administrative unit of Shenzhen has great potential for improving urban management.Conclusions:This paper has taken the theoretical understanding of urban spatial heterogeneity and used it to generate a classification scheme that exploits remotely sensed imagery,infrastructural data available at a municipal level,and object-based spatial analysis.For effective planning and management,the hierarchical levels of landscape classification(level 1),the analysis of use and cover by urban zones(level 2),and the fundamental elements of land cover(level 3),each exposes different respects relevant to city plans and management.展开更多
Progressive population concentration to the urban centres has fuelled urban expansion in both horizontal as well as vertical direction,consequences in the urban landscape change.This growth resulted in posing many com...Progressive population concentration to the urban centres has fuelled urban expansion in both horizontal as well as vertical direction,consequences in the urban landscape change.This growth resulted in posing many complexities towards sustainable urban development which can be counted by observing the changing proportions of natural landscapes and built up areas.Local climate zones(LCZs),a systematic classification of natural lands and built up lands,are identified in Siliguri Municipal Corporation(SMC)and its surrounding region to explore the spatio temporal complexity of urban growth in recent years.Rapid urbanization and population growth of SMC have led to change the building states from low rise to mid and high rise which added an important feature to the urban landscape dynamics of the area.The work intends to provide the vision of spatial urban morphology of the area through investigation of its changing land use and changing urban built space using the LCZ classification.The study shows that the WUDAPT method can accurately generate LCZs,especially the built type LCZs.The results of the proposed LCZ classification scheme are tested using error matrix for the year 2001 and 2021 having coefficient values of 0.79 and 0.81 respectively.The study explores the changing pattern of building states of SMC using LCZ products,which is essential for proper urban planning implementations.展开更多
The goal of this study is to spatially portray Taif’s urban expansion and determine for last 30 years, from 1990 to 2020. It is only including the residential neighborhoods approved by the Taif Municipality, which is...The goal of this study is to spatially portray Taif’s urban expansion and determine for last 30 years, from 1990 to 2020. It is only including the residential neighborhoods approved by the Taif Municipality, which is responsible and organized for urban planning in the city. The geographical location of the city of Taif is a vital crossroad between eastern and western parts of the Kingdom of Saudi Arabia, which made it a tourist destination, as well as commercial and agricultural preference for many years, as it was considered the summer capital of the KSA. Moreover, it serves as the entrance to Makkah city from the eastern side. The proposed study has necessitated because the lack of recent scientific studies that dealt with the spatial analysis of urban expansion and its trends in the city of Taif and follow the stages of expansion during periods of time by relying on remote sensing and geographic information systems (GIS) techniques. The many development projects in the city of Taif, such as Taif International Airport, the new Taif project, and other projects, which will cause an increase in demand for residential, commercial, industrial and service units have also prompted the proposed study. This was investigated using a multitemporal Landsat data for the years of 1990, 2002 and 2020, as well as census data from 1990 to 2020, along with Remote Sensing (RS) and Geographic Information System (GIS) techniques. The results revealed that over the last 30 years, urban land cover has increased by 20,448 (ha) whereas other land covers, such as green area, have decreased significantly by 14,554 (ha). The results also indicate that the increase in urban areas amounted to 114.8% during the period from 1990 to 2020. The locations of new developments such as Taif airport, Taif university, Ministry of Housing projects, etc. were located to the North and Northeast. This is due to the area’s topography, which played a major role in determining the direction of urban expansion. According to the study, multiple urban centers, rising low-density dispersed communities, and leapfrogging growth were all hallmarks of urban expansion in Taif. The study demonstrated that Taif is at risk of ecosystem loss as a result of continued urban expansion. To ensure environmental sustainability, the current effort asks for actions that will restrict urban sprawl and prepare the city for future growth.展开更多
基金The paper is supported by the Research Foundation for OutstandingYoung Teachers , China University of Geosciences ( Wuhan) ( No .CUGQNL0616) Research Foundationfor State Key Laboratory of Geo-logical Processes and Mineral Resources ( No . MGMR2002-02)Hubei Provincial Depart ment of Education (B) .
文摘Urban land provides a suitable location for various economic activities which affect the development of surrounding areas. With rapid industrialization and urbanization, the contradictions in land-use become more noticeable. Urban administrators and decision-makers seek modern methods and technology to provide information support for urban growth. Recently, with the fast development of high-resolution sensor technology, more relevant data can be obtained, which is an advantage in studying the sustainable development of urban land-use. However, these data are only information sources and are a mixture of "information" and "noise". Processing, analysis and information extraction from remote sensing data is necessary to provide useful information. This paper extracts urban land-use information from a high-resolution image by using the multi-feature information of the image objects, and adopts an object-oriented image analysis approach and multi-scale image segmentation technology. A classification and extraction model is set up based on the multi-features of the image objects, in order to contribute to information for reasonable planning and effective management. This new image analysis approach offers a satisfactory solution for extracting information quickly and efficiently.
文摘Spatial and temporal informationon urban infrastructure is essential and requires various land-cover/land-use planning and management applications.Besides,a change in infrastructure has a direct impact on other land-cover and climatic conditions.This study assessed changes in the rate and spatial distribution of Peshawar district’s infrastructure and its effects on Land Surface Temperature(LST)during the years 1996 and 2019.For this purpose,firstly,satellite images of bands7 and 8 ETM+(Enhanced Thematic Mapper)plus and OLI(Operational Land Imager)of 30 m resolution were taken.Secondly,for classification and image processing,remote sensing(RS)applications ENVI(Environment for Visualising Images)and GIS(Geographic Information System)were used.Thirdly,for better visualization and more in-depth analysis of land sat images,pre-processing techniques were employed.For Land use and Land cover(LU/LC)four types of land cover areas were identified-vegetation area,water cover,urbanized area,and infertile land for the years under research.The composition of red,green,and near infra-red bands was used for supervised classification.Classified images were extracted for analyzing the relative infrastructure change.A comparative analysis for the classification of images is performed for SVM(Support Vector Machine)and ANN(Artificial Neural Network).Based on analyzing these images,the result shows the rise in the average temperature from 30.04℃ to 45.25℃.This only possible reason is the increase in the built-up area from 78.73 to 332.78 Area km^(2) from 1996 to 2019.It has also been witnessed that the city’s sides are hotter than the city’s center due to the barren land on the borders.
基金This work received funding support from CNPq(National Counsel of Technological and Scientific Development,process 404104/2013-4)CAPES(Coordination for the Improvement of Higher Education Personnel)and Araucária Foundation
文摘Land cover classification is one of the main components of the modern weather research and forecasting models, which can influence the meteorological variable, and in turn the concentration of air pollutants. In this study the impact of using two traditional land use classifications, the United States Geological Survey (USGS) and the Moderate-resolution Imaging Spectroradiometer (MODIS), were evaluated. The Weather Research and Forecasting model (WRF, version 3.2.1) was run for the period 18 - 22 August, 2014 (dry season) at a grid spacing of 3 km centered on the city of Manaus. The comparison between simulated and ground-based observed data revealed significant differences in the meteorological fields, for instance, the temperature. Compared to USGS, MODIS classification showed better skill in representing observed temperature for urban areas of Manaus, while the two files showed similar results for nearby areas. The analysis of the files suggests that the better quality of the simulations favorable to the MODIS file is straightly related to its better representation of urban class of land use, which is observed to be not adequately represented by USGS.
基金The Second Tibetan Plateau Scientific Expedition and Research Program,No.2019QZKK0406。
文摘Urban planning construction land standard is the technical specification for scientifically allocating various types of urban construction land,and it is the basis for drawing up and revising the overall urban planning scheme.Considering China’s current urban planning construction land standard,many problems exist,such as the gap in the land use control threshold,the lack of regional differences in the climate revision,and failing to consider the topographic factors.To resolve these problems,this study proposed a step-by-step process framework and quantitative calculation method for the establishment and revision of standards in accordance with the principle of Total-Structure control.By setting the conditions,a universal basic standard for construction land was established.Quantitative analysis was then conducted on the relationship between the basic standard and the selected key indicators,such as urban population size,sunshine spacing coefficient,the width of river valleys or inter-montane basins,and terrain slope,among others.Finally,revised standards were formed for climate conditions,topography,and geomorphologic conditions,which were matched with the basic standards.The key results are three-fold:(1)The per capita construction land standard of 95 m~2/person can be used as the total indicator of China’s urban planning basic standard,and the corresponding per capita single construction land comprises 32.50%of residential land,7.42%of public management and public service land,22.50%of industrial land,17.50%of transportation facilities,12.50%of green space,and 7.58%of other land-use types.The results of the revision of the urban population size indicate that the difference in population size has little effect on the total amount of per capita construction land.(2)The climate revision results of per capita residential land and per capita construction land in major cities reveal that the revised climate value varies greatly between north and south China.The revised climate values of the per capita area of construction land vary by latitude as follows:the value at 20°N is 93 m^(2)/person,the value at 30°N is 97 m^(2)/person,the value at 40°N is 103 m^(2)/person,and the value at 50°N is 115 m^(2)/person.The basic standard land value of 95 m^(2)/person is generally distributed across the Xiamen-Guilin-Kunming line.(3)The cities located in mountainous areas,hilly valleys,or inter-montane basins can reduce the allocation of community parks and comprehensive parks when the average width of an existing river valley or inter-montane basin is less than 2 km.When the average width of the valley or inter-montane basin is between 2 km to 4 km,the allocation of the comprehensive parks can be reduced.The revised results of per capita sloping construction land reveal that the terrain slope greatly affects the revised value of per capita construction land.Specifically,the revised value at 3°is 3.68%higher than the basic standard value,and the increase rates at 8°,15°,and 25°are 11.25%,26.49%,and 68.47%,respectively.
文摘This paper examines the utility of high-resolution airborne RGB orthophotos and LiDAR data for mapping residential land uses within the spatial limits of suburb of Athens, Greece. Modem remote sensors deliver ample information from the AOI (area of interest) for the estimation of 2D indicators or with the inclusion of elevation data 3D indicators for the classification of urban land. In this research, two of these indicators, BCR (building coverage ratio) and FAR (floor area ratio) are automatically evaluated. In the pre-processing step, the low resolution elevation data are fused with the high resolution optical data through a mean-shift based discontinuity preserving smoothing algorithm. The outcome is an nDSM (normalized digital surface model) comprised of upsampled elevation data with considerable improvement regarding region filling and "straightness" of elevation discontinuities. Following this step, a MFNN (multilayer feedforward neural network) is used to classify all pixels of the AOI into building or non-building categories. The information derived from the BCR and FAR building indicators, adapted to landscape characteristics of the test area is used to propose two new indices and an automatic post-classification based on the density of buildings.
基金supported by the National Natural Science Foundation of China[grant Nos 41971406,41871292]the Science and Technology Program of Guangdong Province[grant number 2018B020207002]the Science and Technology Program of Guangzhou,China[grant number 201803030034].
文摘The classification of urban functional areas plays an important role in urban planning and resource management.Although previous studies have confirmed that different urban func-tional areas have different morphological structures and Land Surface Temperature(LST)characteristics,these two types of characteristics have rarely been fully integrated and used for functional area classification.In this paper,a new framework for classifying urban functional areas is proposed by combining urban morphological features and LST features.First,metrics are constructed from three levels,namely,building,road and region,which are used to portray urban morphology;LST is retrieved using thermal infrared remote sensing to reflect LST features with four metrics:the average temperature,maximum temperature,temperature difference and standard deviation of temperature.Then,the functional areas are classified into four categories:service/public land,commercial land,residential land and industrial land.A random forest algorithm is used to effectively fuse the features of these two categories and classify the functional areas.The effectiveness of the proposed framework is tested in the study area of Shenzhen City,Guangdong Province.The results show that the combined classification accuracy of the proposed classification method is 0.85,which is 0.26 higher than that of the classification model based on urban morphology and 0.1 higher than that of the classification model based on LST features.The proposed framework verifies that the integration of LST features into urban functional area classification is reliable and effectively combines urban morphology and LST features for functional area classification.
文摘Homeowners’Associations(HOAs)dictate landscape structure and management through legally enforceable land covenants at the neighborhood scale in the USA.Determining the location and spatial extent of HOAs is critical for examining its influence.However,such analysis is confounded by the lack of spatial data at the appropriate unit for such analysis.The purpose of this paper is to develop and realize an open source implementation to automate land parcel classification,which is an initial step towards the goal of determining the impact of HOAs on urban land management.Using Maricopa County,Arizona as a testbed,we found that parcel merging processes reduce the number of subdivisions from 26,042 to 17,269,such that boundaries better align with neighborhood units to which rule sets like land covenants apply.Moreover,after an initial training period,this process was completed in just over 7 hours.This research is an important first step in enabling a number of analysis including determining the location and spatial extent of HOAs regionally and,eventually,nationally and determining proposed links between HOAs and land management outcomes.
基金This work was supported by National Key Research and Development Program of the Ministry of Science and Technology of the People’s Republic of China[2016YFA0600104]and the Cyrus Tang Foundation.
文摘Urban land use information that reflects socio-economic functions and human activities is critically essential for urban planning,land-scape design,environmental management,health promotion,and biodiversity conservation.Land-use maps outlining the distribution,pattern,and composition of essential urban land use categories(EULUC)have facilitated a wide spectrum of applications and further triggered new opportunities in urban studies.New and improved Earth observations,algorithms,and advanced products for extracting thematic urban information,in association with emer-ging social sensing big data and auxiliary crowdsourcing datasets,all together offer great potentials to mapping fine-resolution EULUC from regional to global scales.Here we review the advances of EULUC mapping research and practices in terms of their data,methods,and applications.Based on the historical retrospect,we summarize the challenges and limitations of current EULUC studies regarding sample collection,mixed land use problem,data and model generalization,and large-scale mapping efforts.Finally,we propose and discuss future opportunities,including cross-scale mapping,optimal integration of multi-source features,global sam-ple libraries from crowdsourcing approaches,advanced machine learning and ensembled classification strategy,open portals for data visualization and sharing,multi-temporal mapping of EULUC change,and implications in urban environmental studies,to facil-itate multi-scale fine-resolution EULUC mapping research.
基金European Commission Project,No.ICA4-CT-2002-10004Knowledge Innovation ProjectofChinese Academ y ofSciences,No.KZCX3-SW -146
文摘Landsat ETM/TM data and an artificial neural network (ANN) were applied to analyse the expansion of the city of Xi'an and land use/cover change of its surrounding area between 2000 and 2003. Supervised classification and normalized difference barren index (NDBI) were used respectively to retrieve its urban boundary. Results showed that the urban area increased by an annual rate of 12.3%, with area expansion from 253.37 km^2 in 2000 to 358.60 km^2 in 2003. Large areas of farmland in the north and southwest were converted into urban construction land. The land use/cover changes of Xi'an were mainly caused by fast development of urban economy, population immigration from countryside, great development of infrastructure such as transportation, and huge demands for urban market. In addition, affected by the government policy of “returning farmland to woodland”, some farmland was converted into economic woodland, such as Chinese goosebeerv garden, vineyard etc.
基金This research was funded by the National Key R&D Program of China(Grant No.2017YFC0505801)the National Natural Science Foundation of China(Grant No.41771203 and 41601180)+1 种基金the Shenzhen Ecological Environment Bureau(Grant No.SZCG2018161498)the Shenzhen Environmental Monitoring Center(Grant No.SZCG2018161442 and SZCG2017158233).
文摘Background:Cities are social-ecological systems characterized by remarkably high spatial and temporal heterogeneity,which are closely related to myriad urban problems.However,the tools to map and quantify this heterogeneity are lacking.We here developed a new three-level classification scheme,by considering ecosystem types(level 1),urban function zones(level 2),and land cover elements(level 3),to map and quantify the hierarchical spatial heterogeneity of urban landscapes.Methods:We applied the scheme using an object-based approach for classification using very high spatial resolution imagery and a vector layer of building location and characteristics.We used a top-down classification procedure by conducting the classification in the order of ecosystem types,function zones,and land cover elements.The classification of the lower level was based on the results of the higher level.We used an objectbased methodology to carry out the three-level classification.Results:We found that the urban ecosystem type accounted for 45.3%of the land within the Shenzhen city administrative boundary.Within the urban ecosystem type,residential and industrial zones were the main zones,accounting for 38.4%and 33.8%,respectively.Tree canopy was the dominant element in Shenzhen city,accounting for 55.6%over all ecosystem types,which includes agricultural and forest.However,in the urban ecosystem type,the proportion of tree canopy was only 22.6%because most trees were distributed in the forest ecosystem type.The proportion of trees was 23.2% in industrial zones,2.2%higher than that in residential zones.That information“hidden”in the usual statistical summaries scaled to the entire administrative unit of Shenzhen has great potential for improving urban management.Conclusions:This paper has taken the theoretical understanding of urban spatial heterogeneity and used it to generate a classification scheme that exploits remotely sensed imagery,infrastructural data available at a municipal level,and object-based spatial analysis.For effective planning and management,the hierarchical levels of landscape classification(level 1),the analysis of use and cover by urban zones(level 2),and the fundamental elements of land cover(level 3),each exposes different respects relevant to city plans and management.
文摘Progressive population concentration to the urban centres has fuelled urban expansion in both horizontal as well as vertical direction,consequences in the urban landscape change.This growth resulted in posing many complexities towards sustainable urban development which can be counted by observing the changing proportions of natural landscapes and built up areas.Local climate zones(LCZs),a systematic classification of natural lands and built up lands,are identified in Siliguri Municipal Corporation(SMC)and its surrounding region to explore the spatio temporal complexity of urban growth in recent years.Rapid urbanization and population growth of SMC have led to change the building states from low rise to mid and high rise which added an important feature to the urban landscape dynamics of the area.The work intends to provide the vision of spatial urban morphology of the area through investigation of its changing land use and changing urban built space using the LCZ classification.The study shows that the WUDAPT method can accurately generate LCZs,especially the built type LCZs.The results of the proposed LCZ classification scheme are tested using error matrix for the year 2001 and 2021 having coefficient values of 0.79 and 0.81 respectively.The study explores the changing pattern of building states of SMC using LCZ products,which is essential for proper urban planning implementations.
文摘The goal of this study is to spatially portray Taif’s urban expansion and determine for last 30 years, from 1990 to 2020. It is only including the residential neighborhoods approved by the Taif Municipality, which is responsible and organized for urban planning in the city. The geographical location of the city of Taif is a vital crossroad between eastern and western parts of the Kingdom of Saudi Arabia, which made it a tourist destination, as well as commercial and agricultural preference for many years, as it was considered the summer capital of the KSA. Moreover, it serves as the entrance to Makkah city from the eastern side. The proposed study has necessitated because the lack of recent scientific studies that dealt with the spatial analysis of urban expansion and its trends in the city of Taif and follow the stages of expansion during periods of time by relying on remote sensing and geographic information systems (GIS) techniques. The many development projects in the city of Taif, such as Taif International Airport, the new Taif project, and other projects, which will cause an increase in demand for residential, commercial, industrial and service units have also prompted the proposed study. This was investigated using a multitemporal Landsat data for the years of 1990, 2002 and 2020, as well as census data from 1990 to 2020, along with Remote Sensing (RS) and Geographic Information System (GIS) techniques. The results revealed that over the last 30 years, urban land cover has increased by 20,448 (ha) whereas other land covers, such as green area, have decreased significantly by 14,554 (ha). The results also indicate that the increase in urban areas amounted to 114.8% during the period from 1990 to 2020. The locations of new developments such as Taif airport, Taif university, Ministry of Housing projects, etc. were located to the North and Northeast. This is due to the area’s topography, which played a major role in determining the direction of urban expansion. According to the study, multiple urban centers, rising low-density dispersed communities, and leapfrogging growth were all hallmarks of urban expansion in Taif. The study demonstrated that Taif is at risk of ecosystem loss as a result of continued urban expansion. To ensure environmental sustainability, the current effort asks for actions that will restrict urban sprawl and prepare the city for future growth.