本文简要介绍了日本道路交通信息管理系统(VICS:Vehicle Information and CommunicationSystem)的建设发起、法人构成、系统框架、运行模式等。VICS通过实时向公众发布道路交通信息,由驾车人自行选择道路等措施,较好地解决了道路交通中...本文简要介绍了日本道路交通信息管理系统(VICS:Vehicle Information and CommunicationSystem)的建设发起、法人构成、系统框架、运行模式等。VICS通过实时向公众发布道路交通信息,由驾车人自行选择道路等措施,较好地解决了道路交通中存在的问题。VICS的建设和运行的成功经验,对我国的智能道路建设有很好的借鉴意义,我国道路信息收集和发布等方面已具有了建立类似VICS的条件,有关部门应协手共建我国的智能交通系统(CITS:China Intelligent Transport System),提高道路设施的效能,缓解车辆拥挤状况,缩小与国际先进水平差距,使道路交通管理水平上一个新台阶。展开更多
VICS(Vehicle Information and Communication System)是一个数字数据通讯系统，主要用来通过车辆导航设备为驾驶员提供必要的实时交通信息。日本于1996年开通第一个VICS服务系统，VICS可根据驾驶员的需求，利用图形或者文字的方式提供...VICS(Vehicle Information and Communication System)是一个数字数据通讯系统，主要用来通过车辆导航设备为驾驶员提供必要的实时交通信息。日本于1996年开通第一个VICS服务系统，VICS可根据驾驶员的需求，利用图形或者文字的方式提供有关道路拥堵和各个区域的旅行时间等实时信息，主要是通过利用安装在路旁的信息标志以及车辆导航设备来完成，而利用FM调频广播的信息服务则覆盖了更大的领域和范围。展开更多
Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts ...Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts and their lag time from meteorological droughts at a daily scale.In this study,precipitation data were collected to calculate the standardized precipitation index(SPI),and runoff data simulated by the variable infiltration capacity(VIC)model were utilized to compute the standardized runoff index(SRI).The three-threshold run theory was used to identify drought characteristics in China.These drought characteristics were utilized to investigate spatiotemporal variations,seasonal trends,and temporal changes in areas affected by meteorological and hydrological droughts.Additionally,the interconnections and lag effects between meteorological and hydrological droughts were explored.The results indicated that(1)drought occurred during approximately 28%of the past 34 years in China;(2)drought conditions tended to worsen in autumn and weaken in winter;(3)drought-affected areas shifted from northwest to northeast and finally to southern China;and(4)the correlation between meteorological and hydrological droughts was lower in the northwest and higher in the southeast,with all correlation coefficients exceeding 0.7.The lag times between meteorological and hydrological droughts were longest(5 d)in the Yangtze River,Yellow River,and Hai River basins,and shortest(0 d)in the Tarim River Basin.This study provides a scientific basis for effective early warning of droughts.展开更多
文摘本文简要介绍了日本道路交通信息管理系统(VICS:Vehicle Information and CommunicationSystem)的建设发起、法人构成、系统框架、运行模式等。VICS通过实时向公众发布道路交通信息,由驾车人自行选择道路等措施,较好地解决了道路交通中存在的问题。VICS的建设和运行的成功经验,对我国的智能道路建设有很好的借鉴意义,我国道路信息收集和发布等方面已具有了建立类似VICS的条件,有关部门应协手共建我国的智能交通系统(CITS:China Intelligent Transport System),提高道路设施的效能,缓解车辆拥挤状况,缩小与国际先进水平差距,使道路交通管理水平上一个新台阶。
文摘VICS(Vehicle Information and Communication System)是一个数字数据通讯系统，主要用来通过车辆导航设备为驾驶员提供必要的实时交通信息。日本于1996年开通第一个VICS服务系统，VICS可根据驾驶员的需求，利用图形或者文字的方式提供有关道路拥堵和各个区域的旅行时间等实时信息，主要是通过利用安装在路旁的信息标志以及车辆导航设备来完成，而利用FM调频广播的信息服务则覆盖了更大的领域和范围。
基金supported by the National Key Research and Development Program of China(Grant No.2023YFC3006505)the Fundamental Research Funds for the Central Universities of China(Grant No.B240203007)the National Key Laboratory of Water Disaster Prevention(Grant No.524015222)。
文摘Understanding the evolution and lag effects of droughts is critical to effective drought warning and water resources management.However,due to limited hydrological data,few studies have examined hydrological droughts and their lag time from meteorological droughts at a daily scale.In this study,precipitation data were collected to calculate the standardized precipitation index(SPI),and runoff data simulated by the variable infiltration capacity(VIC)model were utilized to compute the standardized runoff index(SRI).The three-threshold run theory was used to identify drought characteristics in China.These drought characteristics were utilized to investigate spatiotemporal variations,seasonal trends,and temporal changes in areas affected by meteorological and hydrological droughts.Additionally,the interconnections and lag effects between meteorological and hydrological droughts were explored.The results indicated that(1)drought occurred during approximately 28%of the past 34 years in China;(2)drought conditions tended to worsen in autumn and weaken in winter;(3)drought-affected areas shifted from northwest to northeast and finally to southern China;and(4)the correlation between meteorological and hydrological droughts was lower in the northwest and higher in the southeast,with all correlation coefficients exceeding 0.7.The lag times between meteorological and hydrological droughts were longest(5 d)in the Yangtze River,Yellow River,and Hai River basins,and shortest(0 d)in the Tarim River Basin.This study provides a scientific basis for effective early warning of droughts.
