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Determining the road traffic accident hotspots using GIS-based temporal-spatial statistical analytic techniques in Hanoi,Vietnam

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Geo-spatial Information Science 2020年第2期23卷 153-164页

作者： Khanh Giang Le Pei Liu Liang-Tay Lin College of Construction and Development Feng Chia UniversityTaichungTaiwanChina Faculty of Civil Engineering University of Transport and CommunicationsHanoiVietnam

This study applied GIS-based statistical analytic techniques to investigate the influence of accident Severity Index(SI)on temporal-spatial patterns of accident hotspots related to the specific time intervals of day and seasons.Road Traffic Accident(RTA)data in 3 years(2015-2017)in Hanoi,Vietnam were used to analyze and test this approach.Firstly,the RTA data were divided into four seasons in accordance with Hanoi's weather conditions and the time intervals such as the daytime,nighttime,or peak hours.Then,the Kernel Density Estimation(KDE)method was applied to analyze hotspots according to the time intervals and seasons.Finally,the results were presented by using the comap technique.This study considered both analyses with and without SI.The accident SI measures the seriousness of an accident.The approach method is to give higher weights to the more serious accidents,but not with the extremely high values calculated on a direct rate to the accident expenditures.The results showed that both analyses determined the relatively similar hotspots,but the rankings of some hotspots were quite different due to the integration of SI.It is better to take into account SI in determining RTA hotspots because the gained results are more precise and the rankings of hotspots are more accurate.From there,the traffic authorities can easily understand the causes behind each accident and provide reasonable solutions to solve the most dangerous hotspots in case of limited budget and resources appropriately.This is also the first study about this issue in Vietnam,so the contribution of the article will help the traffic authorities easily solve this problem not only in Hanoi but also in other cities.

关键词： Road Traffic Accident(RTA) hotspot GIS temporal-spatial analysis Kernel Density Estimation(KDE) Severity Index(SI)

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Electron acceleration in interaction of magnetic islands in large temporal-spatial turbulent magnetic reconnection

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Earth and Planetary Physics 2019年第1期3卷 17-25页

作者： BoJing Zhu Hui Yan David A Yuen YaoLin Shi Yunnan Observatories Chinese Academy of Sciences Center for Astronomical Mega-Science Chinese Academy of Sciences National Supercomputer Center in Guangzhou Sun Yat-sen University Department of Earth Science and Minnesota Supercomputing Institute University of Minnesota Applied Physics and Applied Mathematics Department Columbia University Key Laboratory of Computing Geodynamics Chinese Academy of Sciences College of Earth and Planetary Sciences University of Chinese Academy of Sciences

A new combined Fermi, betatron, and turbulent electron acceleration mechanism is proposed in interaction of magnetic islands during turbulent magnetic reconnection evolution in explosive astrophysical phenomena at large temporal-spatial scale(LTSTMR), the ratio of observed current sheets thickness to electron characteristic length, electron Larmor radius for low-β and electron inertial length for high-β, is on the order of 10^(10)–10^(11); the ratio of observed evolution time to electron gyroperiod is on the order of 10~7–10~9).The original combined acceleration model is known to be one of greatest importance in the interaction of magnetic islands; it assumes that the continuous kinetic-dynamic temporal-spatial scale evolution occurs as two separate independent processes.In this paper, we reconsider the combined acceleration mechanism by introducing a kinetic-dynamic-hydro full-coupled model instead of the original micro-kinetic or macro-dynamic model.We investigate different acceleration mechanisms in the vicinity of neutral points in magnetic islands evolution, from the stage of shrink and breakup into smaller islands(kinetic scale), to the stage of coalescence and growth into larger islands(dynamic scale), to the stages of constant and quasi-constant(contracting-expanding) islands(hydro scale).As a result, we give for the first time the acceleration efficiencies of different types of acceleration mechanisms in magnetic islands' interactions in solar atmosphere LTSTMR activities(pico-, 10^(–2)–10~5 m; nano-, 10~5–10~6 m; micro-, 10~6–10~7 m; macro-, 10~7–10~8 m; large-,10~8–10~9 m).

关键词： hybrid particle acceleration mechanism large temporal-spatial turbulent magnetic reconnection Hydro-Dynamic-Kinetic model

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The concept, key technologies and applications of temporal-spatial information infrastructure

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Geo-spatial Information Science 2016年第2期19卷中插6-中插6,148-156页

作者： Chengming Li Po Liu Jie Yin Xiaoli Liu Chinese Academy of Surveying and Mapping BeijingChina

Smart city is the development of digital city; as its main supporting technology, the digital city geo-spatial framework has to be upgraded to the temporal-spatial information infrastructure (TSII). first, this paper proposes the concept and basic framework of smart city and defines the concept of TSII - processes, integration, mining analysis, and share time-stamps geographic data - and the related policy, regulations and standards, technology, facilities, mechanism, and human resources. The framework has four components: the benchmark of time and space, temporal-spatial big data, the cloud service platform and the related supporting environment. Second, the temporal-spatial big data and cloud service platform are elaborated. finally, an application of TSII constructed by the Xicheng District Planning Bureau in Beijing is introduced, which provides a useful reference for the construction of smart city.

关键词： Smart city temporal-spatial information infrastructure cloud platform big data data mining

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Quantitative method for evaluating detailed volatility of wind power at multiple temporal-spatial scales

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Global Energy Interconnection 2019年第4期2卷 318-327页

作者： Yongqian Liu Han Wang Shuang Han Jie Yan Li Li Zixin Chen State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources NorthChina Electric Power UniversityBeijing102206P.R.China Chifeng Branch of China Datang Corporation Chifeng City024000Inner Mongolia AutonomousRegionP.R.China

With the increasing proportion of wind power integration, the volatility of wind power brings huge challenges to the safe and stable operation of the electric power system. At present, the indexes commonly used to evaluate the volatility of wind power only consider its overall characteristics, such as the standard deviation of wind power, the average of power variables, etc., while ignoring the detailed volatility of wind power, that is, the features of the frequency distribution of power variables. However, how to accurately describe the detailed volatility of wind power is the key foundation to reduce its adverse influences. To address this, a quantitative method for evaluating the detailed volatility of wind power at multiple temporal-spatial scales is proposed. First, the volatility indexes which can evaluate the detailed fluctuation characteristics of wind power are presented, including the upper confidence limit, lower confidence limit and confidence interval of power variables under the certain confidence level. Then, the actual wind power data from a location in northern China is used to illustrate the application of the proposed indexes at multiple temporal(year–season–month–day) and spatial scales(wind turbine–wind turbines–wind farm–wind farms) using the calculation time windows of 10 min, 30 min, 1 h, and 4 h. Finally, the relationships between wind power forecasting accuracy and its corresponding detailed volatility are analyzed to further verify the effectiveness of the proposed indexes. The results show that the proposed volatility indexes can effectively characterize the detailed fluctuations of wind power at multiple temporal-spatial scales. It is anticipated that the results of this study will serve as an important reference for the reserve capacity planning and optimization dispatch in the electric power system which with a high proportion of renewable energy.

关键词： Wind power Detailed volatility Frequency distribution Multiple temporal-spatial scales Typical days Forecasting accuracy

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Effect of water level fluctuations on temporal-spatial patterns of foraging activities by the wintering Hooded Crane(Grus monacha)

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Chinese Birds 2015年第3期6卷 169-177页

作者： Dongmei Zhang Lizhi Zhou Yunwei Song School of Resources and Environmental Engineering Anhui University Institute of Biodiversity and Wetland Ecology Anhui University Anhui Biodiversity Information Center Shengjin Lake National Nature Reserve of Anhui Province

Background:The Yangtze River floodplain provides important wintering habitats for Hooded Cranes(Grus monacha) in China.Fluctuations in the water level change foraging habitat and food availability,affecting their temporal-spatial patterns of foraging activities.It is of considerable importance to investigate the effect of these fluctuations on food availability for wintering Hooded Cranes and their foraging response to these changes.Understanding their behavior patterns is beneficial in protecting the wintering crane population and restoring their wintering habitats.Methods:A field survey of the winter behavior of cranes was carried out at Shengjin Lake from November in 2013 to April in 2014.Habitat variables,as well as the spatial distribution and behavior patterns of wintering cranes at their foraging sites during five stages of water level fluctuation were collected.Based on this data we analyzed the relationship of foraging behavior relative to water level fluctuations and habitat types.Results:The foraging habitats used by Hooded Cranes varied at the different water level stages.As the water level decreased,the use of meadows and mudflats increased.When the water dropped to its lowest level,the use by the Hooded Crane in the mudflats reached a peak.There were statistically significant differences in time budget in the three types of habitats over the five stages of the water level.In the mudflats,the foraging behavior and maintenance behavior varied significantly with the water level,while the alert behavior showed little variation.Analysis of a generalized linear model showed that the five water level stages and three habitat types had a significant effect on foraging behavior,while the combined effect of these two variables was significant on the foraging time budget and the length of foraging activity of the Hooded Crane.Conclusions:With the decrease in the water level,the use of mudflats by Hooded Cranes increased correspondingly.Food availability in different habitats was affected by changes in the wate

关键词： Water level fluctuations Foraging activity temporal-spatial pattern Hooded Crane Grus monacha

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temporal-spatial change and driving mechanism for regional difference of domestic tourism in China

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Chinese Journal of Population,Resources and Environment 2013年第1期11卷 69-78页

作者： Degen Wang Tian Chen Institute of Geographic Sciences and Natural Research CAS The Graduate School of Chinese Academy of Science Tourism Department of Suzhou University

By using the variation coefficient,Gini coefficient and Theil coefficient,this paper makes preliminary exploration of temporalspatial change features and driving mechanism for regional differences of domestic tourism in China from 1995 to 2009.According to the results,we drew the following conclusions:(1)The regional difference of domestic tourism in China tends to be narrowing generally,and is less than that of inbound tourism,playing an important role in narrowing the overall gap of regional tourism in China.(2)The regional internal difference features:inter-provincial difference in the eastern region and difference among the eastern,central and western regions are comparatively obvious and demonstrate a significantly shrinking tendency,the change tendency is consistent with the change tendency of overall difference and exercises a decisive role in overall difference,whereas the inter-provincial difference in the central and western regions is small and relatively stable,having less influence on the overall difference.(3)The temporal-spatial change in regional difference is featured by:low-level provinces occupy a majority and are concentrated in the central and western regions,showing a tendency of narrowing difference;high-level provinces are concentrated in the eastern region,showing a tendency of spreading to the central and western regions;spatial pattern of regional difference demonstrates 4 types,i.e."proliferation type","polarization type","quiescence type"and"collapse type."(4)The driving force for regional difference of domestic tourism in China comes down to 3 aspects:regional socio-economic attribute,regional transport accessibility level and regional development policy.

关键词： domestic tourism regional difference temporal-spatial change driving mechanism China

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Relationship between the temporal-spatial distribution of archaeological sites and natural environment from the Paleolithic Age to the Tang and Song Dynasties in the Three Gorges Reservoir of Chongqing area

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Chinese Science Bulletin 2008年第S1期53卷 107-128页

作者： ChaoGui Zheng Cheng Zhu YiShun Zhong PengLian Yin JiuJiang Bai ZhiBin Sun Chinese Acad Sci Nanjing Inst Geog and Limnol Nanjing 210008 Peoples R China.

The temporal-spatial distribution features including time distribution,horizontal and vertical spatial distribution of archaeological sites from the Paleolithic Age to the Tang and Song Dynasties in the Three Gorges Reservoir of Chongqing area are analyzed based on GIS spatial analysis.The successive pollen record of deposited peat stratum since the Paleolithic Age in the Dajiuhu Basin of Shennongjia is used in combination with the research of the historical environmental evolution to reconstruct the Paleoenvironment in the Three Gorges Reservoir of Chongqing area.Through the comparison of the temporal-spatial distribution of the archaeological sites and the natural environment,the relation between the distribution of the archaeological sites and the natural environment evolution and disaster changes from the Neolithic Age to the Tang and Song Dynasties has been discussed.Study shows that 677 archaeological sites from the Paleolithic Age to the Tang and Song Dynasties in the Three Gorges Reservoir of Chongqing area increase gradually from west to east and from high land to low land.Most of the sites are distributed along the river and aggregated at the confluence.Obviously,the altitudes of archaeological sites in the Paleolithic Age and the Neolithic Age are much higher than those of historical sites.The analysis suggests:(1)the human beings of every times would like to choose the first or the second river terrace as living sites which are nearer to the water source and are easier to with- stand flood.The pre-historical sites of earlier ages are often located at the higher altitude place because of the tectonic uplift and downcutting of rivers since Holocene.(2)Due to the rugged terrain in Chongqing area,most of the sites are located along the river sides,for example,the wide river valley and terrace,which could provide wider living space caused by the lateral erosion and deposition of the river course.(3)The early residents mainly relied on fishing,hunting and agriculture,and the rugged terrain of the mountainou

关键词： Three Gorges Reservoir of Chongqing area the Paleolithic Age to the Tang and Song Dynasties temporal-spatial distribution of archaeological sites pollen record environmental evolution

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Evolution of temporal-spatial Pattern of Green Development Efficiency in Shandong Province

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Meteorological and Environmental Research 2019年第3期10卷 74-76页

作者： Hou Ailing Guo Fuyou College of Geography and Tourism Qufu Normal University

temporal-spatial differentiation characteristics of green development efficiency in 17 prefecture-level cities of Shandong Province during 2005-2016 were studied by using SBM-undesirable model and spatial auto-correlation analysis.Results showed that ① green development efficiency considering unexpected output could more accurately represent the real cost of regional development,while lower green development efficiency considering unexpected output and traditional green development efficiency illustrated that Shandong Province has spent a lot of resources and environment in the long-term development process.② Green development efficiency of Shandong Province during 2005-2016 showed the change characteristics of "peak-valley-peak-valley",and standard deviation and coefficient of variation of green development efficiency showed fluctuation characteristics in the research period.③ Green development efficiency of Shandong Province had obvious spatial differentiation characteristics,and its polarization differentiation was obvious.

关键词： Green development efficiency Performance measurement temporal-spatial pattern Shandong Province

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temporal-spatial Change Rules of Mangrove in Guangdong Province and Suggestions on Its Protection Measures

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Meteorological and Environmental Research 2019年第2期10卷 91-95页

作者： Xiao Chaoming Yin Juanjuan Liu Xucheng Shenzhen Habitat Environment Technology Review Center Shenzhen Hanyu Environmental Technology Co.Ltd. South China Institute of Environmental Sciences.MEE

Mangrove ecosystem has an important ecological function. But since it is distributed in land-sea alternating region,mangrove is vulnerable to environmental pollution. Mangrove area of Guangdong Province greatly decreased after the 1950 s,and it declined to the minimum in the1990 s and then gradually increased. Mangrove area of Guangdong Province quickly increased from 2001 to now,and its area in 2014 was 19 824. 53 hm^2,in which Zhanjiang accounted for 72%. During 2001-2014,mangrove area of Guangdong Province increased significantly,in which the newly increased mangrove area in Zhanjiang,Yangjiang,Jiangmen,Zhuhai,Guangzhou and Shantou was larger,with obvious increase magnitude; mangrove area in east Guangdong during 2001-2005 increased quickly,while increase magnitude of mangrove area in west Guangdong and the Pearl River Delta was improved significantly after 2005. Additionally,mangrove species in Guangdong Province continuously decreased from south to north,showing as west Guangdong > the Pearl River Delta > east Guangdong. Mangrove of Guangdong Province could be protected strictly from shoreline control,ecological protection,function upgrading,and ecological restoration.

关键词： Mangrove Ecosystem temporal-spatial distribution Protective measures

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temporal-spatial Change of Cr Content in Bottom Waters

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Meteorological and Environmental Research 2017年第5期8卷 125-126页

作者： Yang Dongfang Zhu Sixi Wang Fengyou Yang Xiuqin Zhao Xiaoli Karst Wetland Ecology Research Center Guizhou Minzu UniversityGuiyang 550025China School of Chemistry and Environmental Sciences Guizhou Minzu UniversityGuiyang 550025China North China Sea Environmental Monitoring Center State Oceanic AdministrationQingdao 266033China

Based on the investigation data of Jiaozhou Bay waters in 1981,current situation and horizontal distribution of Cr content in bottom waters of Jiaozhou Bay mouth were studied. Results showed that in bottom waters of Jiaozhou Bay center,Cr content changed from 0. 50 to3. 78 μg/L in April. In August,Cr content changed from 0. 14 to 1. 42 μg/L in bottom waters of Jiaozhou Bay mouth. It showed that Cr content corresponded with national class-one seawater quality standard(50. 00 μg/L) at different times and spaces,and Cr content was far less than5. 00 μg/L. Therefore,under the effect of vertical water body,water quality was clean in bottom waters of Jiaozhou Bay,which was not polluted by Cr. In bottom waters of Jiaozhou Bay center in April and bottom waters of Jiaozhou Bay mouth in August,Cr transported by the river came to the bottom layer from surface layer by passing through water body in temporal-spatial change process. Under the effects of gravity and water flow,Cr continuously and quickly sank to the sea bottom. It verified the sedimentation process of Cr content.

关键词： Cr content Bottom layer distribution Water quality temporal-spatial change Jiaozhou Bay

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