As a key carrier supporting urban ecological health and living environment quality,urban ecological network is a key focus of current urban green space research.Jingzhou City of Hubei Province is taken as the research...As a key carrier supporting urban ecological health and living environment quality,urban ecological network is a key focus of current urban green space research.Jingzhou City of Hubei Province is taken as the research object.Relying on GIS technology platform,MSPA method is used to analyze the landscape pattern of Jingzhou City.On this basis,the landscape connectivity evaluation method is used to accurately identify and extract the source areas with important ecological value in Jingzhou City.Then,the normalization method and weighting method are combined to create a resistance factor evaluation system to construct the resistance surface.Based on the MCR model,the ecological network of Jingzhou City is successfully constructed,and targeted spatial optimization strategies and development suggestions are proposed.展开更多
Smart city refers to the information system with Intemet of things and cloud computing as the core tec hnology and government management and industrial development as the core content,forming a large scale,heterogeneo...Smart city refers to the information system with Intemet of things and cloud computing as the core tec hnology and government management and industrial development as the core content,forming a large scale,heterogeneous and dynamic distributed Internet of things environment between different Internet of things.There is a wide demand for cooperation between equipment and management institutions in the smart city.Therefore,it is necessary to establish a trust mechanism to promote cooperation,and based on this,prevent data disorder caused by the interaction between honest terminals and malicious temminals.However,most of the existing research on trust mechanism is divorced from the Internet of things environment,and does not consider the characteristics of limited computing and storage capacity and large differences of Internet of hings devices,resuling in the fact that the research on abstract trust trust mechanism cannot be directly applied to the Internet of things;On the other hand,various threats to the Internet of things caused by security vulnerabilities such as collision attacks are not considered.Aiming at the security problems of cross domain trusted authentication of Intelligent City Internet of things terminals,a cross domain trust model(CDTM)based on self-authentication is proposed.Unlike most trust models,this model uses self-certified trust.The cross-domain process of internet of things(IoT)terminal can quickly establish a trust relationship with the current domain by providing its trust certificate stored in the previous domain interaction.At the same time,in order to alleviate the collision attack and improve the accuracy of trust evaluation,the overall trust value is calculated by comprehensively considering the quantity weight,time attenuation weight and similarity weight.Finally,the simulation results show that CDTM has good anti collusion attack ability.The success rate of malicious interaction will not increase significantly.Compared with other models,the resource consumption of our proposed model is significantly reduced.展开更多
The dead fuel moisture content(DFMC)is the key driver leading to fire occurrence.Accurately estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timel...The dead fuel moisture content(DFMC)is the key driver leading to fire occurrence.Accurately estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timely deployment of fire-suppression resources.In this study,the DFMC and environmental variables,including air temperature,relative humidity,wind speed,solar radiation,rainfall,atmospheric pressure,soil temperature,and soil humidity,were simultaneously measured in a grassland of Ergun City,Inner Mongolia Autonomous Region of China in 2021.We chose three regression models,i.e.,random forest(RF)model,extreme gradient boosting(XGB)model,and boosted regression tree(BRT)model,to model the seasonal DFMC according to the data collected.To ensure accuracy,we added time-lag variables of 3 d to the models.The results showed that the RF model had the best fitting effect with an R2value of 0.847 and a prediction accuracy with a mean absolute error score of 4.764%among the three models.The accuracies of the models in spring and autumn were higher than those in the other two seasons.In addition,different seasons had different key influencing factors,and the degree of influence of these factors on the DFMC changed with time lags.Moreover,time-lag variables within 44 h clearly improved the fitting effect and prediction accuracy,indicating that environmental conditions within approximately 48 h greatly influence the DFMC.This study highlights the importance of considering 48 h time-lagged variables when predicting the DFMC of grassland fuels and mapping grassland fire risks based on the DFMC to help locate high-priority areas for grassland fire monitoring and prevention.展开更多
Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spat...Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were used.We performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its formation.The results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday AUHI.The urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate zones.The release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate zones.The rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.展开更多
To solve the problems of rural revitalization performance research,a quantitative model of non-oriented range-wide EBM(Epsilon-Based Measure)-GML(Global-Malmquist)based on VRS(Variable Returns to Scale)conditions incl...To solve the problems of rural revitalization performance research,a quantitative model of non-oriented range-wide EBM(Epsilon-Based Measure)-GML(Global-Malmquist)based on VRS(Variable Returns to Scale)conditions including non-desired outputs is constructed.A comprehensive spatio-temporal heterogeneity research index system of rural revitalization performance is also constructed.Taking the typical rural in Chifeng City as an example,the panel data from 2016-2020 are selected for empirical analysis,the conclusions and countermeasures are suggested as follows:1)In general,the rural revitalization performance of Chifeng City increases significantly during the five-year period,with significant spatio-temporal heterogeneity.The overall analysis shows that the overall performance value of rural revitalization in Chifeng City is 0.683 from 2016 to 2020.The highest performance value is 1 and the lowest performance value is 0.389.The performance growth rate increases year by year,with an average annual growth rate of 4.46%.2)From 2016 to 2020,the GML index of rural revitalization performance in Chifeng City is 1.174,showing an increasing trend.Based on the range of change of GML index,Chifeng City can be classified into three types:Continuous improvement,fluctuating improvement and fluctuating decline.3)Niujiayingzi,Guandongche,Zhaidamu,and Qiangangtai rural have the highest degree of technological progress.展开更多
Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human...Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human settlements,it is significant for exploring the evolution characteristics of urban thermal environment and analyzing its driving forces.Taking the Landsat series images as the basic data sources,the winter land surface temperature(LST)of the rapid urbanization area of Fuzhou City in China was quantitatively retrieved from 2001 to 2021.Combing comprehensively the standard deviation ellipse model,profile analysis and GeoDetector model,the spatio-temporal evolution characteristics and influencing factors of the winter urban thermal environment were systematically analyzed.The results showed that the winter LST presented an increasing trend in the study area during 2001–2021,and the winter LST of the central urban regions was significantly higher than the suburbs.There was a strong UHI effect from 2001 to 2021with an expansion trend from the central urban regions to the suburbs and coastal areas in space scale.The LST of green lands and wetlands are significantly lower than croplands,artificial surface and unvegetated lands.Vegetation and water bodies had a significant mitigation effect on UHI,especially in the micro-scale.The winter UHI had been jointly driven by the underlying surface and socio-economic factors in a nonlinear or two-factor interactive enhancement mode,and socio-economic factors had played a leading role.This research could provide data support and decision-making references for rationally planning urban layout and promoting sustainable urban development.展开更多
China is experiencing rapid urbanization and motorization. Urban transport congestion poses a challenge to the cities of China. Policies have been made trying to control the car use and the land use in Chinese cities ...China is experiencing rapid urbanization and motorization. Urban transport congestion poses a challenge to the cities of China. Policies have been made trying to control the car use and the land use in Chinese cities without sound modelling researches. The existing literature on monocentric city modelling has shown that the parameters are critical for the outcome of the modelling. Following the Alonso-type monocentric model, this paper introduces a bi-modal model to simulate the city size, the distribution of land rent and the modal substitution in Chinese cities. We set the key parameters according to the recent available data of China′s cities, and re-explain the hypothesis of the model. Then we make a sensitivity analysis to reveal the impacts of key parameters on the Chinese cities. According to the results, we find that the wage, the price of car use and the agriculture rent have significant impacts on city size. The land supply for the private transport or the public transport has the strongest impacts on car use and the level of transport congestion. The total population of the city and the wage level have strong impacts on land rent. Some results are counter-intuitive, but explainable. We also discuss implication of these results for policy making.展开更多
Data acquisition and modeling are the two important, difficult and costful aspects in a Cybercity project. 2D-GIS is mature and can manage a lot of spatial data. Thus 3D-GIS should make the best of data and technology...Data acquisition and modeling are the two important, difficult and costful aspects in a Cybercity project. 2D-GIS is mature and can manage a lot of spatial data. Thus 3D-GIS should make the best of data and technology of 2D-GIS. Construction of a useful synthetic environment requires integration of multiple types of information like DEM, texture images and 3D representation of objects such as buildings. In this paper, the method for 3D city landscape data model and visualization based on integrated databases is presented. Since the data volume of raster are very huge, special strategies(for example, pyramid gridded method) must be adopted in order to manage raster data efficiently. Three different methods of data acquisition, the proper data structure and a simple modeling method are presented as well. At last, a pilot project of Shanghai Cybercity is illustrated.展开更多
The research work has been seldom done about cloverleaf junction expression in a 3-dimensional city model (3DCM). The main reason is that the cloverleaf junction is often in a complex and enormous construction. Its ma...The research work has been seldom done about cloverleaf junction expression in a 3-dimensional city model (3DCM). The main reason is that the cloverleaf junction is often in a complex and enormous construction. Its main body is bestraddle in air,and has aerial intersections between its parts. This complex feature made cloverleaf junction quite different from buildings and terrain, therefore, it is difficult to express this kind of spatial objects in the same way as for buildings and terrain. In this paper,authors analyze spatial characteristics of cloverleaf junction, propose an all-constraint points TIN algorithm to partition cloverleaf junction road surface, and develop a method to visualize cloverleaf junction road surface using TIN. In order to manage cloverleaf junction data efficiently, the authors also analyzed the mechanism of 3DCM data management, extended BLOB type in relational database, and combined R-tree index to manage 3D spatial data. Based on this extension, an appropriate data展开更多
Today,resource depletion threatens a number of resource-based cities in China.The ecological security problem caused by the long-term exploitation of natural resources is a key issue to be solved in the development of...Today,resource depletion threatens a number of resource-based cities in China.The ecological security problem caused by the long-term exploitation of natural resources is a key issue to be solved in the development of resource-exhausted cities.Using 23 indicators,this study evaluated the ecological security status and development trends of 21 resource-exhausted cities in China from 2011 to 2017.The results showed that from 2011 to 2015,the overall ecological security of this type of city was low,with over 60%of the cities at an unsafe level.However,ecological security improved rapidly after 2016,and by 2017,all of the cities had reached the critical safety level.The top 10 indicators of ecological security included industrial sulfur dioxide emissions,water supply,agricultural fertilizer application,and forest coverage.These 10 indicators’cumulative contribution to ecological security was 48.3%;among them,reducing industrial sulfur dioxide emissions contributed the most at 5.7%.These findings can help governments better understand the ecological security status of resource-exhausted cities,and it can provide a reference for the allocation of funds and other resources to improve the ecological safety of these cities.展开更多
Very recently, we have applied the random walk model to fit the global temperature anomaly, CRUTEM3. With encouraging results, we apply the random walk model to fit the temperature walk that is the conversion of recor...Very recently, we have applied the random walk model to fit the global temperature anomaly, CRUTEM3. With encouraging results, we apply the random walk model to fit the temperature walk that is the conversion of recorded tem-perature and real recorded temperature in 46 gamma world cities from 1901 to 1998 in this study. The results show that the random walk model can fit both temperature walk and real recorded temperature although the fitted results from other climate models are unavailable for comparison in these 46 cities. Therefore, the random walk model can fit not only the global temperature anomaly, but also the real recorded temperatures in various cities around the world.展开更多
Smart sustainable city is that uses the technology to transform their core systems and optimize the exploitation of limited resources;it is a knowledge-based system that provides real-time insights to stakeholders. As...Smart sustainable city is that uses the technology to transform their core systems and optimize the exploitation of limited resources;it is a knowledge-based system that provides real-time insights to stakeholders. As a result of the challenges facing the cities of the Gaza Strip regarding population growth, lack of resources, increased demand for materials, the siege imposed on the Gaza Strip for more than twelve years, the smart city approach can contribute to mitigating these challenges and creating opportunities and solutions for many of these problems. Thus, this study aims to promote sustainable urban development through the adoption of smart city approaches using the city’s 3D representation and analysis capabilities to reflect and define the current situation and formulate a future vision using GIS and Building Information Modeling (BIM) considering Sheikh Hamad city as a case study. This involves developing a GIS web-based 3D model of the urban landscape of the city and creating a geometric descriptive database that includes the various elements of the city such as buildings, services and other facilities. The constructed database is to be automatically updated and can be used to facilitate documentation, transparency and help in decision-making process. The 3D smart city can also benefit stakeholders, government officials, private sectors as well as the city citizens. Therefore, urban services will be more efficient, and the cities of the Gaza Strip will be able to achieve sustainable development and competition in difficult economic, environmental and social conditions. This study recommends the use of BIM and GIS technologies in the transformation to a smart city concept as well as the rehabilitation of existing cadres to enable them to use those technologies to achieve the goal of improving the quality of life and facilitating the daily lives of people.展开更多
As an important sustainable development goal,the creation of low-carbon cities(LCCs)has become crucial to creating livable cities and environmental sustainability.Thus,we aimed to understand the factors that support t...As an important sustainable development goal,the creation of low-carbon cities(LCCs)has become crucial to creating livable cities and environmental sustainability.Thus,we aimed to understand the factors that support the transition of traditional cities to LCCs,by analyzing and synthesizing how to promote practical LCC across 15 pilot municipalities in four regions of Thailand,covering four strategies:City of Trees,City of Waste Minimization,City of Energy Efficiency,and City of Sustainable Consumption.Literature research,in-depth interviews,and observations were employed for data collection,while the 5W(who,says what,in which channel,to whom,and with what effect)and SMCR(sender,message,channel,and receiver)models were used to create a communication analysis framework.Results revealed that the effective activities of municipalities should increase tree planting and implement more serious regulations for the conservation of existing trees.Making compost and establishing waste recycling banks are recommended for rural municipalities,while optimization of garbage and wastewater management systems and facilities should be highlighted in urban municipalities.Moreover,recycling,low-carbon agriculture,second-hand shops/markets,green markets,and homegrown vegetables should be encouraged for sustainable consumption.Working with local municipalities,credible leaders and representatives were the key senders.Additionally,message design should compare the pros and cons of behaviors,connect with local health and tourism,and promote dialogue in easy-to-understand and thought-provoking language.Receivers that drive LCC should have an excellent understanding of LCC practice and its benefits,be public-minded,and have a desire to live in a good environment.展开更多
In 2010,the National Development and Reform Commission launched the low-carbon city(LCC)pilot pro‐gram.The scope of the pilot program was then gradually expanded to address the dilemma concerning eco‐nomic developme...In 2010,the National Development and Reform Commission launched the low-carbon city(LCC)pilot pro‐gram.The scope of the pilot program was then gradually expanded to address the dilemma concerning eco‐nomic development and low-carbon transition.Selecting the second batch of LCCs in China,this study uses a combination of propensity score matching and difference-in-differences models to determine the effect of LCC pilot policies on CO_(2) emission intensity.We also used the mediation effect model to further investigate its in‐ternal mechanism.The findings of the study are as follows.First,the LCC pilot policy plays an important role in reducing carbon emissions.Second,LCC pilots policies reduce CO_(2) emissions through intermediary paths of output adjustment and technological innovation.Third,our heterogeneity analysis reveals that cities with higher levels of economic growth and better levels of human capital have superior carbon emission reduction effects;lastly,non-resource-based cities have better carbon emission reduction effects.展开更多
With the acceleration of urbanization, city complex as an intensive urban organization form has gradually grown up in China. By consulting relevant documents of city complex, emergence background and related concepts ...With the acceleration of urbanization, city complex as an intensive urban organization form has gradually grown up in China. By consulting relevant documents of city complex, emergence background and related concepts of city complex were introduced, landscape design of Chenglong-International was analyzed to propose landscape design principles and concepts of city complex under the compound development model, landscape processing techniques of outdoor functional subareas and transitional areas were introduced to provide useful reference for the landscape design of city complex.展开更多
This paper analyses the overall landscape framework of city road system in ancient and modern China, using the ideal state terrain model which was fi rst recorded by the construction system of the Zhou Dynasty, and su...This paper analyses the overall landscape framework of city road system in ancient and modern China, using the ideal state terrain model which was fi rst recorded by the construction system of the Zhou Dynasty, and summarizes the ideal model of overall landscape framework of city road system, based on Chinese psychological needs of landscape, and conducts the applied research taking Nanchong in Sichuan, China for example.展开更多
In order to promote the research on the evaluation index system of low-carbon city,this paper reviewed and summarized the current evaluation index systems in recent years and the concepts of lowcarbon city in China.Th...In order to promote the research on the evaluation index system of low-carbon city,this paper reviewed and summarized the current evaluation index systems in recent years and the concepts of lowcarbon city in China.The current evaluation index systems of low-carbon city in China could be divided into two types:two class index system and three class index system.The establishment of different index systems basically adheres to the scientific,systematic,operable and dynamic principles,and the target value and weight of evaluation index could be confirmed in multiple ways.This paper analyzed the existing problems in the evaluation index systems of low-carbon city,and came up with some suggestions and advice to promote relevant research.展开更多
This paper studies the relationship between accessibility and housing prices in Dalian by using an improved geographically weighted regression model and house prices, traffic, remote sensing images, etc. Multi-source ...This paper studies the relationship between accessibility and housing prices in Dalian by using an improved geographically weighted regression model and house prices, traffic, remote sensing images, etc. Multi-source data improves the accuracy of the spatial differentiation that reflects the impact of traffic accessibility on house prices. The results are as follows: first, the average house price is 12 436 yuan(RMB)/m^2, and reveals a declining trend from coastal areas to inland areas. The exception was Guilin Street, which demonstrates a local peak of house prices that decreases from the center of the street to its periphery. Second, the accessibility value is 33 minutes on average, excluding northern and eastern fringe areas, which was over 50 minutes. Third, the significant spatial correlation coefficient between accessibility and house prices is 0.423, and the coefficient increases in the southeastern direction. The strongest impact of accessibility on house prices is in the southeastern coast, and can be seen in the Lehua, Yingke, and Hushan communities, while the weakest impact is in the northwestern fringe, and can be seen in the Yingchengzi, Xixiaomo, and Daheishi community areas.展开更多
基金by Jingzhou Science and Technology Program(2023EC45).
文摘As a key carrier supporting urban ecological health and living environment quality,urban ecological network is a key focus of current urban green space research.Jingzhou City of Hubei Province is taken as the research object.Relying on GIS technology platform,MSPA method is used to analyze the landscape pattern of Jingzhou City.On this basis,the landscape connectivity evaluation method is used to accurately identify and extract the source areas with important ecological value in Jingzhou City.Then,the normalization method and weighting method are combined to create a resistance factor evaluation system to construct the resistance surface.Based on the MCR model,the ecological network of Jingzhou City is successfully constructed,and targeted spatial optimization strategies and development suggestions are proposed.
基金This paper was sponsored in part by Beijing Postdoctoral Research Foundation(No.2021-ZZ-077,No.2020-YJ-006)Chongqing Industrial Control System Security Situational Awareness Platform,2019 Industrial Internet Innovation and Development Project-Provincial Industrial Control System Security Situational Awareness Platform,Center for Research and Innovation in Software Engineering,School of Computer and Information Science(Southwest University,Chongqing 400175,China)Chongqing Graduate Education Teaching Reform Research Project(yjg203032).
文摘Smart city refers to the information system with Intemet of things and cloud computing as the core tec hnology and government management and industrial development as the core content,forming a large scale,heterogeneous and dynamic distributed Internet of things environment between different Internet of things.There is a wide demand for cooperation between equipment and management institutions in the smart city.Therefore,it is necessary to establish a trust mechanism to promote cooperation,and based on this,prevent data disorder caused by the interaction between honest terminals and malicious temminals.However,most of the existing research on trust mechanism is divorced from the Internet of things environment,and does not consider the characteristics of limited computing and storage capacity and large differences of Internet of hings devices,resuling in the fact that the research on abstract trust trust mechanism cannot be directly applied to the Internet of things;On the other hand,various threats to the Internet of things caused by security vulnerabilities such as collision attacks are not considered.Aiming at the security problems of cross domain trusted authentication of Intelligent City Internet of things terminals,a cross domain trust model(CDTM)based on self-authentication is proposed.Unlike most trust models,this model uses self-certified trust.The cross-domain process of internet of things(IoT)terminal can quickly establish a trust relationship with the current domain by providing its trust certificate stored in the previous domain interaction.At the same time,in order to alleviate the collision attack and improve the accuracy of trust evaluation,the overall trust value is calculated by comprehensively considering the quantity weight,time attenuation weight and similarity weight.Finally,the simulation results show that CDTM has good anti collusion attack ability.The success rate of malicious interaction will not increase significantly.Compared with other models,the resource consumption of our proposed model is significantly reduced.
基金funded by the National Key Research and Development Program of China Strategic International Cooperation in Science and Technology Innovation Program (2018YFE0207800)the National Natural Science Foundation of China (31971483)。
文摘The dead fuel moisture content(DFMC)is the key driver leading to fire occurrence.Accurately estimating the DFMC could help identify locations facing fire risks,prioritise areas for fire monitoring,and facilitate timely deployment of fire-suppression resources.In this study,the DFMC and environmental variables,including air temperature,relative humidity,wind speed,solar radiation,rainfall,atmospheric pressure,soil temperature,and soil humidity,were simultaneously measured in a grassland of Ergun City,Inner Mongolia Autonomous Region of China in 2021.We chose three regression models,i.e.,random forest(RF)model,extreme gradient boosting(XGB)model,and boosted regression tree(BRT)model,to model the seasonal DFMC according to the data collected.To ensure accuracy,we added time-lag variables of 3 d to the models.The results showed that the RF model had the best fitting effect with an R2value of 0.847 and a prediction accuracy with a mean absolute error score of 4.764%among the three models.The accuracies of the models in spring and autumn were higher than those in the other two seasons.In addition,different seasons had different key influencing factors,and the degree of influence of these factors on the DFMC changed with time lags.Moreover,time-lag variables within 44 h clearly improved the fitting effect and prediction accuracy,indicating that environmental conditions within approximately 48 h greatly influence the DFMC.This study highlights the importance of considering 48 h time-lagged variables when predicting the DFMC of grassland fuels and mapping grassland fire risks based on the DFMC to help locate high-priority areas for grassland fire monitoring and prevention.
基金supported by the National Key R&D Program of China (Grant No.2019YFA0607202)the National Natural Science Foundation of China (Grant Nos. 42021004 and 42005143)+2 种基金support by the Postgraduate Research&Practice Innovation Program of Jiangsu Province (Grant No. KYCX21_0978)support by the Open Research Fund Program of the Key Laboratory of Urban Meteorology,China Meteorological Administration (Grant No. LUM-2023-12)the 333 Project of Jiangsu Province (Grant No. BRA2022023)
文摘Few studies have investigated the spatial patterns of the air temperature urban heat island(AUHI)and its controlling factors.In this study,the data generated by an urban climate model were used to investigate the spatial variations of the AUHI across China and the underlying climate and ecological drivers.A total of 355 urban clusters were used.We performed an attribution analysis of the AUHI to elucidate the mechanisms underlying its formation.The results show that the midday AUHI is negatively correlated with climate wetness(humid:0.34 K;semi-humid:0.50 K;semi-arid:0.73 K).The annual mean midnight AUHI does not show discernible spatial patterns,but is generally stronger than the midday AUHI.The urban–rural difference in convection efficiency is the largest contributor to the midday AUHI in the humid(0.32±0.09 K)and the semi-arid(0.36±0.11 K)climate zones.The release of anthropogenic heat from urban land is the dominant contributor to the midnight AUHI in all three climate zones.The rural vegetation density is the most important driver of the daytime and nighttime AUHI spatial variations.A spatial covariance analysis revealed that this vegetation influence is manifested mainly through its regulation of heat storage in rural land.
基金Research on Local Knowledge Mapping and Planning Application Strategies of Traditional Rural in Qinba Mountains(No.19YJAZH107)Humanities and Social Sciences Research Planning Fund,Ministry of Education,China.
文摘To solve the problems of rural revitalization performance research,a quantitative model of non-oriented range-wide EBM(Epsilon-Based Measure)-GML(Global-Malmquist)based on VRS(Variable Returns to Scale)conditions including non-desired outputs is constructed.A comprehensive spatio-temporal heterogeneity research index system of rural revitalization performance is also constructed.Taking the typical rural in Chifeng City as an example,the panel data from 2016-2020 are selected for empirical analysis,the conclusions and countermeasures are suggested as follows:1)In general,the rural revitalization performance of Chifeng City increases significantly during the five-year period,with significant spatio-temporal heterogeneity.The overall analysis shows that the overall performance value of rural revitalization in Chifeng City is 0.683 from 2016 to 2020.The highest performance value is 1 and the lowest performance value is 0.389.The performance growth rate increases year by year,with an average annual growth rate of 4.46%.2)From 2016 to 2020,the GML index of rural revitalization performance in Chifeng City is 1.174,showing an increasing trend.Based on the range of change of GML index,Chifeng City can be classified into three types:Continuous improvement,fluctuating improvement and fluctuating decline.3)Niujiayingzi,Guandongche,Zhaidamu,and Qiangangtai rural have the highest degree of technological progress.
基金Under the auspices of the Social Science and Humanity on Young Fund of the Ministry of Education of China(No.21YJCZH100)the Scientific Research Project on Outstanding Young of the Fujian Agriculture and Forestry University(No.XJQ201920)+1 种基金the Science and Technology Innovation Special Fund Project of Fujian Agriculture and Forestry University(No.CXZX2021032)the Forestry Peak Discipline Construction Project of Fujian Agriculture and Forestry University(No.72202200205)。
文摘Under the influence of anthropogenic and climate change,the problems caused by urban heat island(UHI)has become increasingly prominent.In order to promote urban sustainable development and improve the quality of human settlements,it is significant for exploring the evolution characteristics of urban thermal environment and analyzing its driving forces.Taking the Landsat series images as the basic data sources,the winter land surface temperature(LST)of the rapid urbanization area of Fuzhou City in China was quantitatively retrieved from 2001 to 2021.Combing comprehensively the standard deviation ellipse model,profile analysis and GeoDetector model,the spatio-temporal evolution characteristics and influencing factors of the winter urban thermal environment were systematically analyzed.The results showed that the winter LST presented an increasing trend in the study area during 2001–2021,and the winter LST of the central urban regions was significantly higher than the suburbs.There was a strong UHI effect from 2001 to 2021with an expansion trend from the central urban regions to the suburbs and coastal areas in space scale.The LST of green lands and wetlands are significantly lower than croplands,artificial surface and unvegetated lands.Vegetation and water bodies had a significant mitigation effect on UHI,especially in the micro-scale.The winter UHI had been jointly driven by the underlying surface and socio-economic factors in a nonlinear or two-factor interactive enhancement mode,and socio-economic factors had played a leading role.This research could provide data support and decision-making references for rationally planning urban layout and promoting sustainable urban development.
基金Under the auspices of National Science and Technology Support Program of China(No.2012BAJ22B05)National Natural Science Foundation of China(No.41401170)
文摘China is experiencing rapid urbanization and motorization. Urban transport congestion poses a challenge to the cities of China. Policies have been made trying to control the car use and the land use in Chinese cities without sound modelling researches. The existing literature on monocentric city modelling has shown that the parameters are critical for the outcome of the modelling. Following the Alonso-type monocentric model, this paper introduces a bi-modal model to simulate the city size, the distribution of land rent and the modal substitution in Chinese cities. We set the key parameters according to the recent available data of China′s cities, and re-explain the hypothesis of the model. Then we make a sensitivity analysis to reveal the impacts of key parameters on the Chinese cities. According to the results, we find that the wage, the price of car use and the agriculture rent have significant impacts on city size. The land supply for the private transport or the public transport has the strongest impacts on car use and the level of transport congestion. The total population of the city and the wage level have strong impacts on land rent. Some results are counter-intuitive, but explainable. We also discuss implication of these results for policy making.
文摘Data acquisition and modeling are the two important, difficult and costful aspects in a Cybercity project. 2D-GIS is mature and can manage a lot of spatial data. Thus 3D-GIS should make the best of data and technology of 2D-GIS. Construction of a useful synthetic environment requires integration of multiple types of information like DEM, texture images and 3D representation of objects such as buildings. In this paper, the method for 3D city landscape data model and visualization based on integrated databases is presented. Since the data volume of raster are very huge, special strategies(for example, pyramid gridded method) must be adopted in order to manage raster data efficiently. Three different methods of data acquisition, the proper data structure and a simple modeling method are presented as well. At last, a pilot project of Shanghai Cybercity is illustrated.
文摘The research work has been seldom done about cloverleaf junction expression in a 3-dimensional city model (3DCM). The main reason is that the cloverleaf junction is often in a complex and enormous construction. Its main body is bestraddle in air,and has aerial intersections between its parts. This complex feature made cloverleaf junction quite different from buildings and terrain, therefore, it is difficult to express this kind of spatial objects in the same way as for buildings and terrain. In this paper,authors analyze spatial characteristics of cloverleaf junction, propose an all-constraint points TIN algorithm to partition cloverleaf junction road surface, and develop a method to visualize cloverleaf junction road surface using TIN. In order to manage cloverleaf junction data efficiently, the authors also analyzed the mechanism of 3DCM data management, extended BLOB type in relational database, and combined R-tree index to manage 3D spatial data. Based on this extension, an appropriate data
基金This work was supported by the Technology R&D Program of Changsha City(nos.kc1702045 and kq1901145)the Key Technology R&D Program of Hunan Province(nos.2016TP2007,2017TP2006,and 2016TP1014).
文摘Today,resource depletion threatens a number of resource-based cities in China.The ecological security problem caused by the long-term exploitation of natural resources is a key issue to be solved in the development of resource-exhausted cities.Using 23 indicators,this study evaluated the ecological security status and development trends of 21 resource-exhausted cities in China from 2011 to 2017.The results showed that from 2011 to 2015,the overall ecological security of this type of city was low,with over 60%of the cities at an unsafe level.However,ecological security improved rapidly after 2016,and by 2017,all of the cities had reached the critical safety level.The top 10 indicators of ecological security included industrial sulfur dioxide emissions,water supply,agricultural fertilizer application,and forest coverage.These 10 indicators’cumulative contribution to ecological security was 48.3%;among them,reducing industrial sulfur dioxide emissions contributed the most at 5.7%.These findings can help governments better understand the ecological security status of resource-exhausted cities,and it can provide a reference for the allocation of funds and other resources to improve the ecological safety of these cities.
文摘Very recently, we have applied the random walk model to fit the global temperature anomaly, CRUTEM3. With encouraging results, we apply the random walk model to fit the temperature walk that is the conversion of recorded tem-perature and real recorded temperature in 46 gamma world cities from 1901 to 1998 in this study. The results show that the random walk model can fit both temperature walk and real recorded temperature although the fitted results from other climate models are unavailable for comparison in these 46 cities. Therefore, the random walk model can fit not only the global temperature anomaly, but also the real recorded temperatures in various cities around the world.
文摘Smart sustainable city is that uses the technology to transform their core systems and optimize the exploitation of limited resources;it is a knowledge-based system that provides real-time insights to stakeholders. As a result of the challenges facing the cities of the Gaza Strip regarding population growth, lack of resources, increased demand for materials, the siege imposed on the Gaza Strip for more than twelve years, the smart city approach can contribute to mitigating these challenges and creating opportunities and solutions for many of these problems. Thus, this study aims to promote sustainable urban development through the adoption of smart city approaches using the city’s 3D representation and analysis capabilities to reflect and define the current situation and formulate a future vision using GIS and Building Information Modeling (BIM) considering Sheikh Hamad city as a case study. This involves developing a GIS web-based 3D model of the urban landscape of the city and creating a geometric descriptive database that includes the various elements of the city such as buildings, services and other facilities. The constructed database is to be automatically updated and can be used to facilitate documentation, transparency and help in decision-making process. The 3D smart city can also benefit stakeholders, government officials, private sectors as well as the city citizens. Therefore, urban services will be more efficient, and the cities of the Gaza Strip will be able to achieve sustainable development and competition in difficult economic, environmental and social conditions. This study recommends the use of BIM and GIS technologies in the transformation to a smart city concept as well as the rehabilitation of existing cadres to enable them to use those technologies to achieve the goal of improving the quality of life and facilitating the daily lives of people.
基金supported by the National Research Council of Thailand(NRCT)and Biodiversity-Based Economy Development Office(Public Organization)(BEDO),[Grant number.49/2559]。
文摘As an important sustainable development goal,the creation of low-carbon cities(LCCs)has become crucial to creating livable cities and environmental sustainability.Thus,we aimed to understand the factors that support the transition of traditional cities to LCCs,by analyzing and synthesizing how to promote practical LCC across 15 pilot municipalities in four regions of Thailand,covering four strategies:City of Trees,City of Waste Minimization,City of Energy Efficiency,and City of Sustainable Consumption.Literature research,in-depth interviews,and observations were employed for data collection,while the 5W(who,says what,in which channel,to whom,and with what effect)and SMCR(sender,message,channel,and receiver)models were used to create a communication analysis framework.Results revealed that the effective activities of municipalities should increase tree planting and implement more serious regulations for the conservation of existing trees.Making compost and establishing waste recycling banks are recommended for rural municipalities,while optimization of garbage and wastewater management systems and facilities should be highlighted in urban municipalities.Moreover,recycling,low-carbon agriculture,second-hand shops/markets,green markets,and homegrown vegetables should be encouraged for sustainable consumption.Working with local municipalities,credible leaders and representatives were the key senders.Additionally,message design should compare the pros and cons of behaviors,connect with local health and tourism,and promote dialogue in easy-to-understand and thought-provoking language.Receivers that drive LCC should have an excellent understanding of LCC practice and its benefits,be public-minded,and have a desire to live in a good environment.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China[Grant number:72173094,72174195].
文摘In 2010,the National Development and Reform Commission launched the low-carbon city(LCC)pilot pro‐gram.The scope of the pilot program was then gradually expanded to address the dilemma concerning eco‐nomic development and low-carbon transition.Selecting the second batch of LCCs in China,this study uses a combination of propensity score matching and difference-in-differences models to determine the effect of LCC pilot policies on CO_(2) emission intensity.We also used the mediation effect model to further investigate its in‐ternal mechanism.The findings of the study are as follows.First,the LCC pilot policy plays an important role in reducing carbon emissions.Second,LCC pilots policies reduce CO_(2) emissions through intermediary paths of output adjustment and technological innovation.Third,our heterogeneity analysis reveals that cities with higher levels of economic growth and better levels of human capital have superior carbon emission reduction effects;lastly,non-resource-based cities have better carbon emission reduction effects.
文摘With the acceleration of urbanization, city complex as an intensive urban organization form has gradually grown up in China. By consulting relevant documents of city complex, emergence background and related concepts of city complex were introduced, landscape design of Chenglong-International was analyzed to propose landscape design principles and concepts of city complex under the compound development model, landscape processing techniques of outdoor functional subareas and transitional areas were introduced to provide useful reference for the landscape design of city complex.
文摘This paper analyses the overall landscape framework of city road system in ancient and modern China, using the ideal state terrain model which was fi rst recorded by the construction system of the Zhou Dynasty, and summarizes the ideal model of overall landscape framework of city road system, based on Chinese psychological needs of landscape, and conducts the applied research taking Nanchong in Sichuan, China for example.
基金Sponsored by Ecology Leading Academic Discipline Project in Jiangsu ProvinceEnvironmental Science Leading Academic Discipline Project in NanjingScientific Research Project in Nanjing Xiaozhuang University(2012NXY24)
文摘In order to promote the research on the evaluation index system of low-carbon city,this paper reviewed and summarized the current evaluation index systems in recent years and the concepts of lowcarbon city in China.The current evaluation index systems of low-carbon city in China could be divided into two types:two class index system and three class index system.The establishment of different index systems basically adheres to the scientific,systematic,operable and dynamic principles,and the target value and weight of evaluation index could be confirmed in multiple ways.This paper analyzed the existing problems in the evaluation index systems of low-carbon city,and came up with some suggestions and advice to promote relevant research.
基金Under the auspices of National Natural Science Foundation of China(No.41471140,41771178)Liaoning Province Outstanding Youth Program(No.LJQ2015058)
文摘This paper studies the relationship between accessibility and housing prices in Dalian by using an improved geographically weighted regression model and house prices, traffic, remote sensing images, etc. Multi-source data improves the accuracy of the spatial differentiation that reflects the impact of traffic accessibility on house prices. The results are as follows: first, the average house price is 12 436 yuan(RMB)/m^2, and reveals a declining trend from coastal areas to inland areas. The exception was Guilin Street, which demonstrates a local peak of house prices that decreases from the center of the street to its periphery. Second, the accessibility value is 33 minutes on average, excluding northern and eastern fringe areas, which was over 50 minutes. Third, the significant spatial correlation coefficient between accessibility and house prices is 0.423, and the coefficient increases in the southeastern direction. The strongest impact of accessibility on house prices is in the southeastern coast, and can be seen in the Lehua, Yingke, and Hushan communities, while the weakest impact is in the northwestern fringe, and can be seen in the Yingchengzi, Xixiaomo, and Daheishi community areas.