With global climate change, population growth,and economic development in the twenty-first century,large cyclonic storm surges may result in devastating effects in some coastal areas of the world. However, due to the ...With global climate change, population growth,and economic development in the twenty-first century,large cyclonic storm surges may result in devastating effects in some coastal areas of the world. However, due to the deficiency of global data and large-scale modeling efforts, the assessment and mapping of potential storm surge impacts at the global level are limited. In this article,the potential inundated area of global coastal zones is projected using information diffusion theory, based on the historical hourly sea-level observation records from the University of Hawaii Sea Level Center(UHSLC), considering variations in coastal morphology and tropical cyclone tracks. Combined with global demographic and GDP data,population and GDP at risk of storm surge impacts are calculated, mapped, and validated through the comparison with historical losses. The resulting potential impact maps provide a preliminary outlook on risks that may help governments of countries to make storm surge disaster prevention and reduction plans.展开更多
Applications of VANETs(Vehicular Ad hoc Networks)have their own requirements and challenges in wireless communication technology.Although regarded as the rst standard for VANETs,IEEE 802.11p is still in the eld-trial ...Applications of VANETs(Vehicular Ad hoc Networks)have their own requirements and challenges in wireless communication technology.Although regarded as the rst standard for VANETs,IEEE 802.11p is still in the eld-trial stage.Recently,LTE V2X(Long-Term Evolution Vehicular to X)appeared as a systematic V2X solution based on TD-LTE(Time Division Long-Term Evolution)4G.It is regarded as the most powerful competitor to 802.11p.We conduct link level simulations of LTE V2X and DSRC(Dedicated Short-Range Communication)for several di erent types of scenarios.Simulation results show that LTE V2X can achieve the same BLER(Block Error Ratio)with a lower SNR(Signal Noise Ratio)than DSRC.A more reliable link can be guaranteed by LTE V2X,which can achieve the same BLER with lower receiving power than DSRC.The coverage area of LTE V2X is larger than that of DSRC.展开更多
Human proximity to water and its dynamics are important to understanding the socio-hydrological dilemma between using floodplains and avoiding flood risk.However,previous studies have not distinguished between the wat...Human proximity to water and its dynamics are important to understanding the socio-hydrological dilemma between using floodplains and avoiding flood risk.However,previous studies have not distinguished between the water proximity of built-up land in floodplains(BLF)and the water proximity of built-up land outside floodplains(BLOF).This article provides a new and spatiotemporal perspective of the BLF water proximities for understanding the changing flood risk in China.The results show that China’s BLFs had an average water proximity of 5.41 km in 2014.Most of the BLFs(62%,25.889103 km2)were located within 3 km of waterbodies.From 1990 to 2014,China’s BLFs increased rapidly by 81%from23.069103 km2 to 41.749103 km2,of which a large portion(57%)was concentrated in water surroundings(≤km),shortening the distance between BLFs and waterbodies by 169 m.The BLF growth concentrated in water surroundings even in areas where BLFs have an overall increasing distance from waterbodies.Both the increases in the BLFs and their proximity to waterbodies can increase flood exposure and exacerbate flood risk.The scientific community and policymakers should pay attention not only to the volume of BLF growth,but also its spatial relationship with waterbodies.展开更多
Digital Elevation Models(DEMs)play a critical role in hydrologic and hydraulic modeling.Flood inundation mapping is highly dependent on the accuracy of DEMs.Various vertical differences exist among open access DEMs as...Digital Elevation Models(DEMs)play a critical role in hydrologic and hydraulic modeling.Flood inundation mapping is highly dependent on the accuracy of DEMs.Various vertical differences exist among open access DEMs as they use various observation satellites and algorithms.The problem is particularly acute in small,flat coastal cities.Thus,it is necessary to assess the differences of the input of DEMs in flood simulation and to reduce anomalous errors of DEMs.In this study,we first conducted urban flood simulation in the Huangpu River Basin in Shanghai by using the LISFLOOD-FP hydrodynamic model and six open-access DEMs(SRTM,MERIT,CoastalDEM,GDEM,NASADEM,and AW3D30),and analyzed the differences in the results of the flood inundation simulations.Then,we processed the DEMs by using two statistically based methods and compared the results with those using the original DEMs.The results show that:(1)the flood inundation mappings using the six original DEMs are significantly different under the same simulation conditions—this indicates that only using a single DEM dataset may lead to bias of flood mapping and is not adequate for high confidence analysis of exposure and flood management;and(2)the accuracy of a DEM corrected by the Dixon criterion for predicting inundation extent is improved,in addition to reducing errors in extreme water depths—this indicates that the corrected datasets have some performance improvement in the accuracy of flood simulation.A freely available,accurate,high-resolution DEM is needed to support robust flood mapping.Flood-related researchers,practitioners,and other stakeholders should pay attention to the uncertainty caused by DEM quality.展开更多
基金Acknowledgments This work was funded by the Chinese National Basic Research Program(973 Program):“Global Change and Environmental Risk Relationships and Adaptability Paradigm”(2012CB955404)the Innovative Research Group Project of National Natural Science Foundation of China(41321001)the 111 project“Hazard and Risk Science Base at Beijing Normal University”under Grant B08008,Ministry of Education and State Administration of Foreign Experts Affairs,China.
文摘With global climate change, population growth,and economic development in the twenty-first century,large cyclonic storm surges may result in devastating effects in some coastal areas of the world. However, due to the deficiency of global data and large-scale modeling efforts, the assessment and mapping of potential storm surge impacts at the global level are limited. In this article,the potential inundated area of global coastal zones is projected using information diffusion theory, based on the historical hourly sea-level observation records from the University of Hawaii Sea Level Center(UHSLC), considering variations in coastal morphology and tropical cyclone tracks. Combined with global demographic and GDP data,population and GDP at risk of storm surge impacts are calculated, mapped, and validated through the comparison with historical losses. The resulting potential impact maps provide a preliminary outlook on risks that may help governments of countries to make storm surge disaster prevention and reduction plans.
基金This work is supported in part by the National Science and Technology Major Projects of China(No.2017ZX03001014)the National Science Fund for Distinguished Young Scholars(No.61425012)the National Science Foundation Project(No.61300183).
文摘Applications of VANETs(Vehicular Ad hoc Networks)have their own requirements and challenges in wireless communication technology.Although regarded as the rst standard for VANETs,IEEE 802.11p is still in the eld-trial stage.Recently,LTE V2X(Long-Term Evolution Vehicular to X)appeared as a systematic V2X solution based on TD-LTE(Time Division Long-Term Evolution)4G.It is regarded as the most powerful competitor to 802.11p.We conduct link level simulations of LTE V2X and DSRC(Dedicated Short-Range Communication)for several di erent types of scenarios.Simulation results show that LTE V2X can achieve the same BLER(Block Error Ratio)with a lower SNR(Signal Noise Ratio)than DSRC.A more reliable link can be guaranteed by LTE V2X,which can achieve the same BLER with lower receiving power than DSRC.The coverage area of LTE V2X is larger than that of DSRC.
基金funded by the National Key Research and Development Program of China(2017YFC1503001)the National Natural Science Foundation of China(Grant Nos.41871200,41730642,51761135024)+1 种基金the Shanghai Sailing Program(No.19YF1413700)the China Postdoctoral Science Foundation(No.2019M651429)。
文摘Human proximity to water and its dynamics are important to understanding the socio-hydrological dilemma between using floodplains and avoiding flood risk.However,previous studies have not distinguished between the water proximity of built-up land in floodplains(BLF)and the water proximity of built-up land outside floodplains(BLOF).This article provides a new and spatiotemporal perspective of the BLF water proximities for understanding the changing flood risk in China.The results show that China’s BLFs had an average water proximity of 5.41 km in 2014.Most of the BLFs(62%,25.889103 km2)were located within 3 km of waterbodies.From 1990 to 2014,China’s BLFs increased rapidly by 81%from23.069103 km2 to 41.749103 km2,of which a large portion(57%)was concentrated in water surroundings(≤km),shortening the distance between BLFs and waterbodies by 169 m.The BLF growth concentrated in water surroundings even in areas where BLFs have an overall increasing distance from waterbodies.Both the increases in the BLFs and their proximity to waterbodies can increase flood exposure and exacerbate flood risk.The scientific community and policymakers should pay attention not only to the volume of BLF growth,but also its spatial relationship with waterbodies.
基金the National Natural Science Foundation of China(42001096,41730646)the Shanghai Sailing Program(19YF1413700)+2 种基金the China Postdoctoral Science Foundation(2019M651429)East China Normal University Institute of Belt and Road&Global Development(ECNU-BRGD-202106)the National Key R&D Program of China(2017YFC1503001,2017YFE0100700).
文摘Digital Elevation Models(DEMs)play a critical role in hydrologic and hydraulic modeling.Flood inundation mapping is highly dependent on the accuracy of DEMs.Various vertical differences exist among open access DEMs as they use various observation satellites and algorithms.The problem is particularly acute in small,flat coastal cities.Thus,it is necessary to assess the differences of the input of DEMs in flood simulation and to reduce anomalous errors of DEMs.In this study,we first conducted urban flood simulation in the Huangpu River Basin in Shanghai by using the LISFLOOD-FP hydrodynamic model and six open-access DEMs(SRTM,MERIT,CoastalDEM,GDEM,NASADEM,and AW3D30),and analyzed the differences in the results of the flood inundation simulations.Then,we processed the DEMs by using two statistically based methods and compared the results with those using the original DEMs.The results show that:(1)the flood inundation mappings using the six original DEMs are significantly different under the same simulation conditions—this indicates that only using a single DEM dataset may lead to bias of flood mapping and is not adequate for high confidence analysis of exposure and flood management;and(2)the accuracy of a DEM corrected by the Dixon criterion for predicting inundation extent is improved,in addition to reducing errors in extreme water depths—this indicates that the corrected datasets have some performance improvement in the accuracy of flood simulation.A freely available,accurate,high-resolution DEM is needed to support robust flood mapping.Flood-related researchers,practitioners,and other stakeholders should pay attention to the uncertainty caused by DEM quality.