When a vehicle travels in urban areas, onboard global positioning system (GPS) signals may be obstructed by high-rise buildings and thereby cannot provide accurate positions. It is proposed to perform localization b...When a vehicle travels in urban areas, onboard global positioning system (GPS) signals may be obstructed by high-rise buildings and thereby cannot provide accurate positions. It is proposed to perform localization by registering ground images to a 2D building boundary map which is generated from aerial images. Multilayer feature graphs (MFG) is employed to model building facades from the ground images. MFG was reported in the previous work to facilitate the robot scene understand- ing in urhan areas. By constructing MFG, the 2D/3D positions of features can be obtained, inclu- cling line segments, ideal lines, and all primary vertical planes. Finally, a voting-based feature weighted localization method is developed based on MFGs and the 2D building boundary map. The proposed method has been implemented and validated in physical experiments. In the proposed ex- periments, the algorithm has achieved an overall localization accuracy of 2.2m, which is better than commercial GPS working in open environments.展开更多
Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent transportation.Lowcost Inertial Navigation System a...Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent transportation.Lowcost Inertial Navigation System and Global Navigation Satellite System(INS/GNSS)integrated navigation systems have been an important means of fulfilling the above quest due to the complementary error characteristics between INS and GNSS.The complex urban driving environment requires the system sufficiently adaptive to keep up with the time-varying measurement noise and sufficiently robust to cope with measurement outliers and prior uncertainties.However,many efforts lack a balance between adaptability and robustness.In this paper,a novel positioning method with both adaptability and robustness is proposed by coupling the Mahalanobis distance method,the Variational Bayesian method and the student’s t-distribution in one process(M-VBt method).This method is robust against non-Gaussian noise and priori uncertainties,plus adaptive against measurement noise uncertainty and time-varying noise.The field test results show that the M-VBt method(especially the Mahalanobis distance part)has significantly improved the system performance in the complex urban driving environment.展开更多
The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the i...The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the impact of urban block landscape environment on thermal comfort in China,collected by CNKI(China National Knowledge Infrastructure)from 2002 to 2022,are used as the research object.Through bibliometric statistical analysis,LLR algorithm,and cluster analysis,the current research status of the impact of urban block landscape environment on thermal comfort in China is analyzed and processed,and its external characteristics are identified.Using the information visualization software CiteSpace,the research topics in the field of the impact of urban block landscape environment on thermal comfort are presented in the form of knowledge graphs.Through co-occurrence analysis of keywords and trend of word frequency changes,the development trends of research hotspots and cutting-edge fields of the impact of urban block landscape environment on thermal comfort are determined,hoping to provide reference for future research in this field.展开更多
Urban waterfront human settlements have gradually become a hot topic for research in recent years.Using CiteSpace,597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted...Urban waterfront human settlements have gradually become a hot topic for research in recent years.Using CiteSpace,597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted out,and the following characteristics were found:(1)The research hotspots transitioned from thermal comfort evaluation to the functional mechanism of water bodies,and then to the impact on the environment and residents’behavior.(2)The integration of disciplines has promoted the diversification of perspectives on urban waterfront human settlements,and the content has become more concentrated in interdisciplinary fields.Research on corresponding technology and methods of urban waterfront human settlement has improved,and so has the extensiveness of the experiments.(3)The research on urban waterfront human settlement from the perspective of ecology has been improving.The research focuses more on the harmonious coexistence of ecological and cultural values and human beings.展开更多
Sustainable Cities:Assessing the Performance and Practice of Urban Environments Authors:Pierre Laconte,Chris Gossop Year:2016 Publisher:I.B.Tauris & Co.Ltd ISBN:9781784532321(288 pages,in English) How to build sus...Sustainable Cities:Assessing the Performance and Practice of Urban Environments Authors:Pierre Laconte,Chris Gossop Year:2016 Publisher:I.B.Tauris & Co.Ltd ISBN:9781784532321(288 pages,in English) How to build sustainable cities has always been a common concern to the world for a long period of time.Sustainable development usually includes three dimensions:economy,society。展开更多
This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance th...This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance the quality and reliability of the energy spectrum data, we devised a temporal energy window. This partitioned the time-series detector response data, resulting in energy spectra that emphasize the vital information pertaining to radioactive materials. We then extracted characteristic features of these energy spectra, relying on the formation mechanism and measurement principles of the gammaray instrument spectrum. These features encompassed aggregated counts, peak-to-flat ratios, and peak-to-peak ratios. This methodology not only simplified the interpretation of the energy spectra's physical significance but also eliminated the necessity for peak searching and individual peak analyses. Given the requirements of imbalanced multi-classification, we created a detection and identification model using a weighted k-nearest neighbors(KNN) framework. This model recognized that energy spectra of identical radioactive materials exhibit minimal inter-class similarity. Consequently, it considerably boosted the classification accuracy of minority classes, enhancing the classifier's overall efficacy. We also executed a series of comparative experiments. Established methods for radionuclide identification classification, such as standard KNN, support vector machine, Bayesian network, and random tree, were used for comparison purposes. Our proposed algorithm realized an F1 measure of 0.9868 on the time-series detector response data, reflecting a minimum enhancement of 0.3% in comparison with other techniques. The results conclusively show that our algorithm outperforms others when applied to time-series detector response data in urban contexts.展开更多
Despite frequent use of digital devices in everyday life,cost-effective measurement of public health issues in urban areas is still challenging.This study was,therefore,planned to extract land-use types using object-b...Despite frequent use of digital devices in everyday life,cost-effective measurement of public health issues in urban areas is still challenging.This study was,therefore,planned to extract land-use types using object-based and spatial metric approaches to explore the dengue incidence in relation to the surrounding environment in near real-time using Google and Advanced Land Observation Satellite images.The characterised image showed useful classification of an urban areawith 77%accuracy and 0.68 kappa.Geospatial analysis on public health data indicated that most of the dengue cases were found in densely populated areas surrounded by dense vegetation.People living in independent houses having sparsely vegetated surroundings were found to be less vulnerable.Disease incidence was more prevalent in people of 5-24 years of age(67%);while in terms of occupation,mostly students,the unemployed,labourers and farmers(88%)were affected.In general,males were affected slightly more(10%)than females.Proximity analyses indicated that most of the dengue cases were around institutions(40%),religious places(18%)and markets(15%).Thus,usage of Digital Earth scalable tools for monitoring health issues would open new ways for maintaining a healthy and sustainable society in the years ahead.展开更多
Background:Dengue fever(DF)is a mosquito-borne infectious disease that has threatened tropical and subtropical regions in recent decades.An early and targeted warning of a dengue epidemic is important for vector contr...Background:Dengue fever(DF)is a mosquito-borne infectious disease that has threatened tropical and subtropical regions in recent decades.An early and targeted warning of a dengue epidemic is important for vector control.Current studies have primarily determined weather conditions to be the main factor for dengue forecasting,thereby neglecting that environmental suitability for mosquito breeding is also an important factor,especially in fine-grained intra-urban settings.Considering that street-view images are promising for depicting physical environments,this study proposes a framework for facilitating fine-grained intra-urban dengue forecasting by integrating the urban environments measured from street-view images.展开更多
A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century...A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century,climate changes and,due to industrial development,forest areas were under air pollution.Based on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth century.The environment has changed,and the growth and development of plantations has slowed.Pine yields(-34%stand volume)and their life expectancy(on average 50 years)have decreased.These changes are critical for forestry and for the management of forests in urban centers.Due to the decline in growth,ecosystem functions by urban forests has decreased.In order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.展开更多
Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorptio...Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.展开更多
The ecological environment of industrial wasteland has been severely damaged,and problems such as environmental pollution,sharp decline in biodiversity,and ecological damage frequently occur.Therefore,reasonable renov...The ecological environment of industrial wasteland has been severely damaged,and problems such as environmental pollution,sharp decline in biodiversity,and ecological damage frequently occur.Therefore,reasonable renovation of industrial wasteland has become an urgent issue to be resolved.Earth art originates from nature and integrates with industrial wasteland,which plays a guiding role in promoting the upgrading and transformation of industrial wasteland landscapes,and is of great significance for the healthy development of urban environment,improving urban human settlements,and other issues.The combination of land art and urban industrial wasteland landscape transformation can guide the healthy development of urban environment.展开更多
[Objective] The aim was to study on construction of overall water environment in Xi'an. [Method] The study discussed necessity and basic principles of over-all restoration and construction of "Chang'an Eight Water...[Objective] The aim was to study on construction of overall water environment in Xi'an. [Method] The study discussed necessity and basic principles of over-all restoration and construction of "Chang'an Eight Water" from urban planning, and explored related methods from long term planning and concrete construction approaches. [Result] The study proposed that urban landscape substrates of "Chang' an Eight Water" should be restored based on overall planning about urban water environment, change of linear metabolism, and construction of drainage circulation system. Furthermore, self-circulation and purification of rainfall and sewage could be made use of there in view of present urban water environment. In addition, urban "metabolism" should be restored progressively to improve urban environment with consideration of water catchment, storage, and diversion. [Conclusion] We should take the initiative to catch the special opportunity to build Xi'an into an international metropolis with overall planning, designing and implementation, which will be conducive to reconstruction of water system and pleasant surroundings, and to presentation of urban ecosystem and context in "Chang'an Eight Water", providing many opportunities for urban development.展开更多
Urban areas face significant challenges in maintaining water quality amidst increasing urbanization and changing climatic patterns. This study investigates the complex interplay between meteorological variables and wa...Urban areas face significant challenges in maintaining water quality amidst increasing urbanization and changing climatic patterns. This study investigates the complex interplay between meteorological variables and water quality parameters in Nairobi City, focusing on the impacts of rainfall and temperature on surface water quality. Data from multiple sources, including the Water Resources Authority, Nairobi Water and Sewerage Company, and the World Bank’s Climate Change Knowledge Portal, were analyzed to assess the relationships between meteorological variables (rainfall and temperature) and water quality parameters (such as electroconductivity, biochemical oxygen demand, chloride, and pH). The analysis reveals varying impacts of rainfall and temperature on different water quality parameters. While parameters like iron and pH show strong relationships with both rainfall and temperature, others such as ammonia and nitrate exhibit moderate relationships. Additionally, the study highlights the influence of runoff, urbanization, and industrial activities on water quality, emphasizing the need for holistic management approaches. Recommendations encompass the establishment of annual publications on Nairobi River water quality, online accessibility of water quality data, development of hydrological models, spatial analysis, and fostering cross-disciplinary research collaborations. Implementing these recommendations can enhance water quality management practices, mitigate risks, and safeguard environmental integrity in Nairobi City.展开更多
Considering the urban characteristics, a customized multi-scale numerical modeling system is established to simulate the urban meteorological environment. The system mainly involves three spatial scales: the urban sca...Considering the urban characteristics, a customized multi-scale numerical modeling system is established to simulate the urban meteorological environment. The system mainly involves three spatial scales: the urban scale, urban sub-domain scale, and single to few buildings scale. In it, different underlying surface types are employed, the building drag factor is used to replace its roughness in the influence on the urban wind field, the effects of building distribution, azimuth and screening of shortwave radiation are added, and the influence of anthropogenic heating is also taken into account. All the numerical tests indicate that the simulated results are reasonably in agreement with the observational data, so the system can be used to simulate the urban meteorological environment. Making use of it, the characteristics of the meteorological environment from the urban to urban sub-domain scales, even the among-buildings scale, can be recognized. As long as the urban planning scheme is given, the corresponding simulated results can be obtained so as to meet the need of optimizing urban planning.展开更多
Urbanization,especially urban land expansion,has a profound influence on the urban thermal environment.Cities in Northeast China face remarkably uneven development and environmental issues,and thus it is necessary to ...Urbanization,especially urban land expansion,has a profound influence on the urban thermal environment.Cities in Northeast China face remarkably uneven development and environmental issues,and thus it is necessary to strengthen the diagnosis of thermal environmental pressure brought by urbanization.In this study,multi remote sensing imageries and statistical approaches,involving piecewise linear regression(PLR),were used to explore urban expansion and its effects on the thermal environment of Changchun City in Jilin Province,China.Results show that Changchun experienced rapid urban expansion from 2000 to 2020,with urban built-up areas increasing from 171.77 to 525.14 km^(2).The area of the city’s urban heat island(UHI)increased dramatically,during both day and night.Using PLR,a positive linear correlation of built-up density with land surface temperature(LST)was detected,with critical breakpoints of 70%-80%during the daytime and 40%-50%at nighttime.Above the thresholds,the magnitude of LST in response to built-up density significantly increased with intensifying urbanization,especially for nighttime LST.An analysis of the relative frequency distributions(RFDs)of LST reveals that rapid urbanization resulted in a significant increase of mean LST in newly urbanized areas,but had weak effects on daytime LST change in existing urban area.Urban expansion also contributed to a constant decrease of spatial heterogeneity of LST in existing urban area,especially at daytime.However,in newly urbanized areas,the spatial heterogeneity of LST was decreased during the daytime but increased at nighttime due to urbanization.展开更多
Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area...Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area in Gansu Province with very vulnerable and sensitive natural environment but long history of oasis economy, as an example, evaluated the sustainability of its environment and analyzed the scenarios of Wuwei’s household energy consumption, waste discharge in transportation industry, primary industry, secondary industry, tertiary industry, by the integration of the systematical dynamics model Stella and Polestar language to simulate the future development of the research area. The results showed that, first, the developing model of IU was propitious to Wuwei City named for oasis economy and vulnerable natural environment. The strategy of "Intensive Urbanization" can change the structure of energy utilization, and improve the efficiency of energy utilization. Second, the proportion of domestic energy consumption will decrease with industrialization and economic development, while that of tertiary industry, secondary industry and transportation will gradually grow up according to strategy of "Intensive Urbanization". Third, the Wuwei City is facing a severe eco-environmental crisis under the conventional patterns of development and a better future under a sustainable urbanization scenario, in the next 10 to 20 years. The different developing trends were clarified and the relative countermeasures were put forward for the policy makers according to the driving forces.展开更多
The accelerated urbanization has resulted in new soil erosion in the Loess Plateau region since the 1980s. A concept of urban erosion and its impacts on environment are discussed. The experimental studies and field in...The accelerated urbanization has resulted in new soil erosion in the Loess Plateau region since the 1980s. A concept of urban erosion and its impacts on environment are discussed. The experimental studies and field investigations show that those loose silt and earth piles formed by urban construction can be eroded seriously: Under stormy rain, the amount of sediment from steep man-dumped slope is 10.8–12.2 times that of from uncovered slope land; the result of experiments with the wind tunnel also shows that the damage to the surface structure of dry loess can cause serious soil erosion by wind in some cities of the region. Even if in the urban built-up area, there are many loose sandy soil, mud and silt, which are washed into rivers by city’s ground flow in the rainy season. So, anthropogenically induced soil erosion has made soil erosion more serious around the urban areas. And the urban eroded environment has several characteristics such as fragility, complexity, seasonality and quick variability. Urban areas witness a quick economic growth and have more construction projects than rural areas, which brings more intensive changes of environments during a short period of time or adds some new elements to the erosion system. Therefore erosion has experienced more intensive impact by human activities. So, the possible impact of urbanization on erosion environment must be taken into consideration when designing or planning to exploit natural resources or to develop urban areas in the Loess Plateau.展开更多
In addition to purifying water, constructed wetland has become an important ecological landscape in city. The characteristics and key design points of constructed wetland under the ecological principles were explored,...In addition to purifying water, constructed wetland has become an important ecological landscape in city. The characteristics and key design points of constructed wetland under the ecological principles were explored, taking the Jingyue Lake in Zhongxiang City, Hubei Province for example, treatment processes were designed for different infl ow waters on the basis of site analysis to facilitate the water environment control and ecological landscape construction, ecological theories were applied to explore functional layouts and landscape designs of wetland, to build a favorable ecological environment of urban wetland and design outstanding wetland ecological landscapes.展开更多
Urbanization is a potential factor in economic development, which is a main route to social development. As the scale of urbanization expands, the quality of the urban water environment may deteriorate, which can have...Urbanization is a potential factor in economic development, which is a main route to social development. As the scale of urbanization expands, the quality of the urban water environment may deteriorate, which can have a negative impact on sustainable urbanization. Therefore, a comprehensive understanding of the functions of the urban water environment is landscape, culture, and economy. Furthermore, a the urban water environment, which is associated necessary, including its security, resources, ecology, deep analysis is required of the theoretical basis of with geographical location, landscape ecology, and a low-carbon economy. In this paper, we expound the main principles for constructing a system for the urban water environment (including sustainable development, ecological priority, and regional differ- ences), and suggest the content of an urban water environmental system. Such a system contains a nat- ural water environment, an economic water environment, and a social water environment. The natural water environment is the base, an effective economic water environment is the focus, and a healthy social water environment is the essence of such a system. The construction of an urban water environment should rely on a comprehensive security system, complete scientific theory, and advanced technology.展开更多
The aim of this paper is to develop a Multi-Actor Geo-Collaborative Device to improve the processes of household waste collect (HWC) in urban areas. The proposed device will be tested in the Lamkansa district, in the ...The aim of this paper is to develop a Multi-Actor Geo-Collaborative Device to improve the processes of household waste collect (HWC) in urban areas. The proposed device will be tested in the Lamkansa district, in the southwestern part of Casablanca city, Morocco. The approach used is a systemic analysis of communication in order to act on a territory. We have been inspired by several methodological developments concerning multi-actor processes of land use planning. We focused our work on the involvement of the inhabitants in the process of household waste collect. The results show that the urban population can help and contribute to the development of complementary solutions to improve the urban environment and their living environment. Moreover, by integrating citizens in HWC processes, as well as decision communication, we can reduce household waste management costs and make it faster and more efficient, through a geo-collaborative, participatory and incentive logic. The approach described in this article is original, not only considering the technologies used to present and share the collected information, but also regarding the concept of integrating several actors in a collaborative/incentive mode. It arouses great interest by combining geomatics with communication and information sciences. It contributes to improve the participation of the inhabitants in the life of their urban environment in order to establish a reinforced dialogue on the future of their city and public health. Also, it involves the development and testing of new devices and tools for multi-actor collaboration.展开更多
基金Supported by the National High Technology Research and Development Program of China(No.2012AA041403)National Natural Science Foundation of China(No.60905061,61305107)+1 种基金the Fundamental Research Funds for the Central Universities(No.ZXH2012N003)the Scientific Research Funds for Civil Aviation University of China(No.2012QD23x)
文摘When a vehicle travels in urban areas, onboard global positioning system (GPS) signals may be obstructed by high-rise buildings and thereby cannot provide accurate positions. It is proposed to perform localization by registering ground images to a 2D building boundary map which is generated from aerial images. Multilayer feature graphs (MFG) is employed to model building facades from the ground images. MFG was reported in the previous work to facilitate the robot scene understand- ing in urhan areas. By constructing MFG, the 2D/3D positions of features can be obtained, inclu- cling line segments, ideal lines, and all primary vertical planes. Finally, a voting-based feature weighted localization method is developed based on MFGs and the 2D building boundary map. The proposed method has been implemented and validated in physical experiments. In the proposed ex- periments, the algorithm has achieved an overall localization accuracy of 2.2m, which is better than commercial GPS working in open environments.
基金funded by National Natural Science Foundation of China(No.61901015)。
文摘Achieving higher accuracy positioning results in urban environments at a lower cost has been an important pursuit in areas such as autonomous driving and intelligent transportation.Lowcost Inertial Navigation System and Global Navigation Satellite System(INS/GNSS)integrated navigation systems have been an important means of fulfilling the above quest due to the complementary error characteristics between INS and GNSS.The complex urban driving environment requires the system sufficiently adaptive to keep up with the time-varying measurement noise and sufficiently robust to cope with measurement outliers and prior uncertainties.However,many efforts lack a balance between adaptability and robustness.In this paper,a novel positioning method with both adaptability and robustness is proposed by coupling the Mahalanobis distance method,the Variational Bayesian method and the student’s t-distribution in one process(M-VBt method).This method is robust against non-Gaussian noise and priori uncertainties,plus adaptive against measurement noise uncertainty and time-varying noise.The field test results show that the M-VBt method(especially the Mahalanobis distance part)has significantly improved the system performance in the complex urban driving environment.
基金the National Natural Science Foundation of China(51708004)Beijing Youth Teaching Master Team Construction Project(108051360023XN261)Yuyou Talent Training Program of North China University of Technology(215051360020XN160/009).
文摘The landscape environment of urban blocks plays a significant role in improving the comfort of urban thermal environment and promoting green and high-quality development.The 342 papers related to the research on the impact of urban block landscape environment on thermal comfort in China,collected by CNKI(China National Knowledge Infrastructure)from 2002 to 2022,are used as the research object.Through bibliometric statistical analysis,LLR algorithm,and cluster analysis,the current research status of the impact of urban block landscape environment on thermal comfort in China is analyzed and processed,and its external characteristics are identified.Using the information visualization software CiteSpace,the research topics in the field of the impact of urban block landscape environment on thermal comfort are presented in the form of knowledge graphs.Through co-occurrence analysis of keywords and trend of word frequency changes,the development trends of research hotspots and cutting-edge fields of the impact of urban block landscape environment on thermal comfort are determined,hoping to provide reference for future research in this field.
文摘Urban waterfront human settlements have gradually become a hot topic for research in recent years.Using CiteSpace,597 publications from 2017 to 2023 that were retrieved from the Web of Science were analyzed and sorted out,and the following characteristics were found:(1)The research hotspots transitioned from thermal comfort evaluation to the functional mechanism of water bodies,and then to the impact on the environment and residents’behavior.(2)The integration of disciplines has promoted the diversification of perspectives on urban waterfront human settlements,and the content has become more concentrated in interdisciplinary fields.Research on corresponding technology and methods of urban waterfront human settlement has improved,and so has the extensiveness of the experiments.(3)The research on urban waterfront human settlement from the perspective of ecology has been improving.The research focuses more on the harmonious coexistence of ecological and cultural values and human beings.
基金supported by the National Natural Science Foundation of China(No.51378278)
文摘Sustainable Cities:Assessing the Performance and Practice of Urban Environments Authors:Pierre Laconte,Chris Gossop Year:2016 Publisher:I.B.Tauris & Co.Ltd ISBN:9781784532321(288 pages,in English) How to build sustainable cities has always been a common concern to the world for a long period of time.Sustainable development usually includes three dimensions:economy,society。
基金supported by the National Defense Fundamental Research Projects (Nos. JCKY2020404C004 and JCKY2022404C005)Sichuan Science and Technology Program (No. 22NSFSC0044)。
文摘This study introduces a novel algorithm to detect and identify radioactive materials in urban settings using time-series detector response data. To address the challenges posed by varying backgrounds and to enhance the quality and reliability of the energy spectrum data, we devised a temporal energy window. This partitioned the time-series detector response data, resulting in energy spectra that emphasize the vital information pertaining to radioactive materials. We then extracted characteristic features of these energy spectra, relying on the formation mechanism and measurement principles of the gammaray instrument spectrum. These features encompassed aggregated counts, peak-to-flat ratios, and peak-to-peak ratios. This methodology not only simplified the interpretation of the energy spectra's physical significance but also eliminated the necessity for peak searching and individual peak analyses. Given the requirements of imbalanced multi-classification, we created a detection and identification model using a weighted k-nearest neighbors(KNN) framework. This model recognized that energy spectra of identical radioactive materials exhibit minimal inter-class similarity. Consequently, it considerably boosted the classification accuracy of minority classes, enhancing the classifier's overall efficacy. We also executed a series of comparative experiments. Established methods for radionuclide identification classification, such as standard KNN, support vector machine, Bayesian network, and random tree, were used for comparison purposes. Our proposed algorithm realized an F1 measure of 0.9868 on the time-series detector response data, reflecting a minimum enhancement of 0.3% in comparison with other techniques. The results conclusively show that our algorithm outperforms others when applied to time-series detector response data in urban contexts.
文摘Despite frequent use of digital devices in everyday life,cost-effective measurement of public health issues in urban areas is still challenging.This study was,therefore,planned to extract land-use types using object-based and spatial metric approaches to explore the dengue incidence in relation to the surrounding environment in near real-time using Google and Advanced Land Observation Satellite images.The characterised image showed useful classification of an urban areawith 77%accuracy and 0.68 kappa.Geospatial analysis on public health data indicated that most of the dengue cases were found in densely populated areas surrounded by dense vegetation.People living in independent houses having sparsely vegetated surroundings were found to be less vulnerable.Disease incidence was more prevalent in people of 5-24 years of age(67%);while in terms of occupation,mostly students,the unemployed,labourers and farmers(88%)were affected.In general,males were affected slightly more(10%)than females.Proximity analyses indicated that most of the dengue cases were around institutions(40%),religious places(18%)and markets(15%).Thus,usage of Digital Earth scalable tools for monitoring health issues would open new ways for maintaining a healthy and sustainable society in the years ahead.
文摘Background:Dengue fever(DF)is a mosquito-borne infectious disease that has threatened tropical and subtropical regions in recent decades.An early and targeted warning of a dengue epidemic is important for vector control.Current studies have primarily determined weather conditions to be the main factor for dengue forecasting,thereby neglecting that environmental suitability for mosquito breeding is also an important factor,especially in fine-grained intra-urban settings.Considering that street-view images are promising for depicting physical environments,this study proposes a framework for facilitating fine-grained intra-urban dengue forecasting by integrating the urban environments measured from street-view images.
基金supported by the Russian State Agrarian University–Moscow Timiryazev Agricultural Academy。
文摘A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present day.In the twentieth century,climate changes and,due to industrial development,forest areas were under air pollution.Based on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth century.The environment has changed,and the growth and development of plantations has slowed.Pine yields(-34%stand volume)and their life expectancy(on average 50 years)have decreased.These changes are critical for forestry and for the management of forests in urban centers.Due to the decline in growth,ecosystem functions by urban forests has decreased.In order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.
基金supported by the National Natural Science Foundation of China(Nos.61805257,41905130)in part by the China Postdoctoral Science Foundation(Nos.2020M671383,2020M681517)in part by the Science and Technology Development Plan Foundation of Suzhou(No.SS202148).
文摘Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.
文摘The ecological environment of industrial wasteland has been severely damaged,and problems such as environmental pollution,sharp decline in biodiversity,and ecological damage frequently occur.Therefore,reasonable renovation of industrial wasteland has become an urgent issue to be resolved.Earth art originates from nature and integrates with industrial wasteland,which plays a guiding role in promoting the upgrading and transformation of industrial wasteland landscapes,and is of great significance for the healthy development of urban environment,improving urban human settlements,and other issues.The combination of land art and urban industrial wasteland landscape transformation can guide the healthy development of urban environment.
文摘[Objective] The aim was to study on construction of overall water environment in Xi'an. [Method] The study discussed necessity and basic principles of over-all restoration and construction of "Chang'an Eight Water" from urban planning, and explored related methods from long term planning and concrete construction approaches. [Result] The study proposed that urban landscape substrates of "Chang' an Eight Water" should be restored based on overall planning about urban water environment, change of linear metabolism, and construction of drainage circulation system. Furthermore, self-circulation and purification of rainfall and sewage could be made use of there in view of present urban water environment. In addition, urban "metabolism" should be restored progressively to improve urban environment with consideration of water catchment, storage, and diversion. [Conclusion] We should take the initiative to catch the special opportunity to build Xi'an into an international metropolis with overall planning, designing and implementation, which will be conducive to reconstruction of water system and pleasant surroundings, and to presentation of urban ecosystem and context in "Chang'an Eight Water", providing many opportunities for urban development.
文摘Urban areas face significant challenges in maintaining water quality amidst increasing urbanization and changing climatic patterns. This study investigates the complex interplay between meteorological variables and water quality parameters in Nairobi City, focusing on the impacts of rainfall and temperature on surface water quality. Data from multiple sources, including the Water Resources Authority, Nairobi Water and Sewerage Company, and the World Bank’s Climate Change Knowledge Portal, were analyzed to assess the relationships between meteorological variables (rainfall and temperature) and water quality parameters (such as electroconductivity, biochemical oxygen demand, chloride, and pH). The analysis reveals varying impacts of rainfall and temperature on different water quality parameters. While parameters like iron and pH show strong relationships with both rainfall and temperature, others such as ammonia and nitrate exhibit moderate relationships. Additionally, the study highlights the influence of runoff, urbanization, and industrial activities on water quality, emphasizing the need for holistic management approaches. Recommendations encompass the establishment of annual publications on Nairobi River water quality, online accessibility of water quality data, development of hydrological models, spatial analysis, and fostering cross-disciplinary research collaborations. Implementing these recommendations can enhance water quality management practices, mitigate risks, and safeguard environmental integrity in Nairobi City.
基金sponsored by the Key Project(96-920-34-07)of the Ministry of Science and Technology,Chinathe Nationa1 Natura1 Science Foundation of China(40333027).
文摘Considering the urban characteristics, a customized multi-scale numerical modeling system is established to simulate the urban meteorological environment. The system mainly involves three spatial scales: the urban scale, urban sub-domain scale, and single to few buildings scale. In it, different underlying surface types are employed, the building drag factor is used to replace its roughness in the influence on the urban wind field, the effects of building distribution, azimuth and screening of shortwave radiation are added, and the influence of anthropogenic heating is also taken into account. All the numerical tests indicate that the simulated results are reasonably in agreement with the observational data, so the system can be used to simulate the urban meteorological environment. Making use of it, the characteristics of the meteorological environment from the urban to urban sub-domain scales, even the among-buildings scale, can be recognized. As long as the urban planning scheme is given, the corresponding simulated results can be obtained so as to meet the need of optimizing urban planning.
基金Under the auspices of the Natural Science Foundation of Jilin Province(No.20200201048JC)。
文摘Urbanization,especially urban land expansion,has a profound influence on the urban thermal environment.Cities in Northeast China face remarkably uneven development and environmental issues,and thus it is necessary to strengthen the diagnosis of thermal environmental pressure brought by urbanization.In this study,multi remote sensing imageries and statistical approaches,involving piecewise linear regression(PLR),were used to explore urban expansion and its effects on the thermal environment of Changchun City in Jilin Province,China.Results show that Changchun experienced rapid urban expansion from 2000 to 2020,with urban built-up areas increasing from 171.77 to 525.14 km^(2).The area of the city’s urban heat island(UHI)increased dramatically,during both day and night.Using PLR,a positive linear correlation of built-up density with land surface temperature(LST)was detected,with critical breakpoints of 70%-80%during the daytime and 40%-50%at nighttime.Above the thresholds,the magnitude of LST in response to built-up density significantly increased with intensifying urbanization,especially for nighttime LST.An analysis of the relative frequency distributions(RFDs)of LST reveals that rapid urbanization resulted in a significant increase of mean LST in newly urbanized areas,but had weak effects on daytime LST change in existing urban area.Urban expansion also contributed to a constant decrease of spatial heterogeneity of LST in existing urban area,especially at daytime.However,in newly urbanized areas,the spatial heterogeneity of LST was decreased during the daytime but increased at nighttime due to urbanization.
基金Under theauspicesofKey Program of the National Natural Science Foundation of China (No .90102013) and KeyInnovationSub-projectof Chinese Academy of Sciences(No .KZCX1-10-07-04 )
文摘Based on data of questionnaire and field survey and two developing models of Business As Usual (BAU) and the Intensive Urbanization (IU), this article, taking Wuwei City, a medium size city and typical oasis arid area in Gansu Province with very vulnerable and sensitive natural environment but long history of oasis economy, as an example, evaluated the sustainability of its environment and analyzed the scenarios of Wuwei’s household energy consumption, waste discharge in transportation industry, primary industry, secondary industry, tertiary industry, by the integration of the systematical dynamics model Stella and Polestar language to simulate the future development of the research area. The results showed that, first, the developing model of IU was propitious to Wuwei City named for oasis economy and vulnerable natural environment. The strategy of "Intensive Urbanization" can change the structure of energy utilization, and improve the efficiency of energy utilization. Second, the proportion of domestic energy consumption will decrease with industrialization and economic development, while that of tertiary industry, secondary industry and transportation will gradually grow up according to strategy of "Intensive Urbanization". Third, the Wuwei City is facing a severe eco-environmental crisis under the conventional patterns of development and a better future under a sustainable urbanization scenario, in the next 10 to 20 years. The different developing trends were clarified and the relative countermeasures were put forward for the policy makers according to the driving forces.
基金National Natural Science Foundation of China, No. 40071005.
文摘The accelerated urbanization has resulted in new soil erosion in the Loess Plateau region since the 1980s. A concept of urban erosion and its impacts on environment are discussed. The experimental studies and field investigations show that those loose silt and earth piles formed by urban construction can be eroded seriously: Under stormy rain, the amount of sediment from steep man-dumped slope is 10.8–12.2 times that of from uncovered slope land; the result of experiments with the wind tunnel also shows that the damage to the surface structure of dry loess can cause serious soil erosion by wind in some cities of the region. Even if in the urban built-up area, there are many loose sandy soil, mud and silt, which are washed into rivers by city’s ground flow in the rainy season. So, anthropogenically induced soil erosion has made soil erosion more serious around the urban areas. And the urban eroded environment has several characteristics such as fragility, complexity, seasonality and quick variability. Urban areas witness a quick economic growth and have more construction projects than rural areas, which brings more intensive changes of environments during a short period of time or adds some new elements to the erosion system. Therefore erosion has experienced more intensive impact by human activities. So, the possible impact of urbanization on erosion environment must be taken into consideration when designing or planning to exploit natural resources or to develop urban areas in the Loess Plateau.
文摘In addition to purifying water, constructed wetland has become an important ecological landscape in city. The characteristics and key design points of constructed wetland under the ecological principles were explored, taking the Jingyue Lake in Zhongxiang City, Hubei Province for example, treatment processes were designed for different infl ow waters on the basis of site analysis to facilitate the water environment control and ecological landscape construction, ecological theories were applied to explore functional layouts and landscape designs of wetland, to build a favorable ecological environment of urban wetland and design outstanding wetland ecological landscapes.
文摘Urbanization is a potential factor in economic development, which is a main route to social development. As the scale of urbanization expands, the quality of the urban water environment may deteriorate, which can have a negative impact on sustainable urbanization. Therefore, a comprehensive understanding of the functions of the urban water environment is landscape, culture, and economy. Furthermore, a the urban water environment, which is associated necessary, including its security, resources, ecology, deep analysis is required of the theoretical basis of with geographical location, landscape ecology, and a low-carbon economy. In this paper, we expound the main principles for constructing a system for the urban water environment (including sustainable development, ecological priority, and regional differ- ences), and suggest the content of an urban water environmental system. Such a system contains a nat- ural water environment, an economic water environment, and a social water environment. The natural water environment is the base, an effective economic water environment is the focus, and a healthy social water environment is the essence of such a system. The construction of an urban water environment should rely on a comprehensive security system, complete scientific theory, and advanced technology.
文摘The aim of this paper is to develop a Multi-Actor Geo-Collaborative Device to improve the processes of household waste collect (HWC) in urban areas. The proposed device will be tested in the Lamkansa district, in the southwestern part of Casablanca city, Morocco. The approach used is a systemic analysis of communication in order to act on a territory. We have been inspired by several methodological developments concerning multi-actor processes of land use planning. We focused our work on the involvement of the inhabitants in the process of household waste collect. The results show that the urban population can help and contribute to the development of complementary solutions to improve the urban environment and their living environment. Moreover, by integrating citizens in HWC processes, as well as decision communication, we can reduce household waste management costs and make it faster and more efficient, through a geo-collaborative, participatory and incentive logic. The approach described in this article is original, not only considering the technologies used to present and share the collected information, but also regarding the concept of integrating several actors in a collaborative/incentive mode. It arouses great interest by combining geomatics with communication and information sciences. It contributes to improve the participation of the inhabitants in the life of their urban environment in order to establish a reinforced dialogue on the future of their city and public health. Also, it involves the development and testing of new devices and tools for multi-actor collaboration.