The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurr...The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurred.The ongoing surge in high-resolution data allows novel opportunities for quantification of hazards and exposure.Here,we provide a global spatial synthesis of urban populations'exposure to riverinefloods and storm surges in 1990 and 2015.Our results reveal that,owing to rapid economic development globally in a large proportion of exposed areas,most of the exposure has shifted from low-income to middle-income countries.Asia dominates as a continent.The total growth of human exposure continues,suggesting that disaster risk reduction policies and implementation call for enduring effort.展开更多
Data on global population distribution are a strategic resource currently in high demand in an age of new Development Agendas that call for universal inclusiveness of people.However,quality,detail,and age of census da...Data on global population distribution are a strategic resource currently in high demand in an age of new Development Agendas that call for universal inclusiveness of people.However,quality,detail,and age of census data varies significantly by country and suffers from shortcomings that propagate to derived population grids and their applications.In this work,the improved capabilities of recent remote sensing-derived global settlement data to detect and mitigate major discrepancies with census data is explored.Open layers mapping builtup presence were used to revise census units deemed as‘unpopulated’and to harmonize population distribution along coastlines.Automated procedures to detect and mitigate these anomalies,while minimizing changes to census geometry,preserving the regional distribution of population,and the overall counts were developed,tested,and applied.The two procedures employed for the detection of deficiencies in global census data obtained high rates of true positives,after verification and validation.Results also show that the targeted anomalies were significantly mitigated and are encouraging for further uses of free and open geospatial data derived from remote sensing in complementing and improving conventional sources of fundamental population statistics.展开更多
In recent decades,the continuous growth in the population has significantly changed the area of human settlements across the globe.The change of human settlements has brought great challenges to human development,envi...In recent decades,the continuous growth in the population has significantly changed the area of human settlements across the globe.The change of human settlements has brought great challenges to human development,environmental change,resource allocation,and disaster prediction and prevention.In the current paper,we integrate data products provided by the European Commission,Joint Research Centre with multi-source remote sensing data to analyze the changing trends of global human settlements under varying geographical distributions from 1990 to 2014.The results demonstrate that on the global scale,human settlements are generally distributed in Europe,East Asia,Southeast Asia,South Asia,the eastern United States,the Gulf Coast and the coast of Oceania,with most of them distributed in urban agglomerations and coastal areas.Global human settlements have continued to grow over the past 25 years,mainly in East Asia,Western Europe and the United States.The area of human settlements in eastern Europe has been slightly reduced.The distribution of human settlements is affected by climate,water and terrain conditions.Humans were more likely to have settled in temperate regions with wetter climates,and most of the human settlements are located within 500 km of the coastline and 30 km of land-based water sources.Our results can provide insights into further investigations of the spatio-temporal dynamics of human settlements and its connections to ecological and environmental issues in a changing world.展开更多
There is an increasing availability of geospatial data describing patterns of human settlement and population such as various global remote-sensing based built-up land layers,fine-grained census-based population estim...There is an increasing availability of geospatial data describing patterns of human settlement and population such as various global remote-sensing based built-up land layers,fine-grained census-based population estimates,and publicly available cadastral and building footprint data.This development constitutes new integrative modeling opportunities to characterize the continuum of urban,peri-urban,and rural settlements and populations.However,little research has been done regarding the agreement between such data products in measuring human presence which is measured by different proxy variables(i.e.presence of built-up structures derived from different remote sensors,census-derived population counts,or cadastral land parcels).In this work,we quantitatively evaluate and cross-compare the ability of such data to model the urban continuum,using a unique,integrated validation database of cadastral and building footprint data,U.S.census data,and three different versions of the Global Human Settlement Layer(GHSL)derived from remotely sensed data.We identify advantages and shortcomings of these data types across different geographic settings in the U.S.,which will inform future data users on implications of data accuracy and suitability for a given application,even in data-poor regions of the world.展开更多
基金Maa-ja Vesitekniikan Tuki RyDepartment of Built Environment(OV),Aalto University。
文摘The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurred.The ongoing surge in high-resolution data allows novel opportunities for quantification of hazards and exposure.Here,we provide a global spatial synthesis of urban populations'exposure to riverinefloods and storm surges in 1990 and 2015.Our results reveal that,owing to rapid economic development globally in a large proportion of exposed areas,most of the exposure has shifted from low-income to middle-income countries.Asia dominates as a continent.The total growth of human exposure continues,suggesting that disaster risk reduction policies and implementation call for enduring effort.
文摘Data on global population distribution are a strategic resource currently in high demand in an age of new Development Agendas that call for universal inclusiveness of people.However,quality,detail,and age of census data varies significantly by country and suffers from shortcomings that propagate to derived population grids and their applications.In this work,the improved capabilities of recent remote sensing-derived global settlement data to detect and mitigate major discrepancies with census data is explored.Open layers mapping builtup presence were used to revise census units deemed as‘unpopulated’and to harmonize population distribution along coastlines.Automated procedures to detect and mitigate these anomalies,while minimizing changes to census geometry,preserving the regional distribution of population,and the overall counts were developed,tested,and applied.The two procedures employed for the detection of deficiencies in global census data obtained high rates of true positives,after verification and validation.Results also show that the targeted anomalies were significantly mitigated and are encouraging for further uses of free and open geospatial data derived from remote sensing in complementing and improving conventional sources of fundamental population statistics.
基金The National Science and Technology Key Project(2016YFB0502301)。
文摘In recent decades,the continuous growth in the population has significantly changed the area of human settlements across the globe.The change of human settlements has brought great challenges to human development,environmental change,resource allocation,and disaster prediction and prevention.In the current paper,we integrate data products provided by the European Commission,Joint Research Centre with multi-source remote sensing data to analyze the changing trends of global human settlements under varying geographical distributions from 1990 to 2014.The results demonstrate that on the global scale,human settlements are generally distributed in Europe,East Asia,Southeast Asia,South Asia,the eastern United States,the Gulf Coast and the coast of Oceania,with most of them distributed in urban agglomerations and coastal areas.Global human settlements have continued to grow over the past 25 years,mainly in East Asia,Western Europe and the United States.The area of human settlements in eastern Europe has been slightly reduced.The distribution of human settlements is affected by climate,water and terrain conditions.Humans were more likely to have settled in temperate regions with wetter climates,and most of the human settlements are located within 500 km of the coastline and 30 km of land-based water sources.Our results can provide insights into further investigations of the spatio-temporal dynamics of human settlements and its connections to ecological and environmental issues in a changing world.
基金This research has been funded,in part,by the U.S.National Science Foundation(Directorate for Social,Behavioral and Economic Sciences)award#1416860 to the City University of New York,the Population Council,the National Center for Atmospheric Research and the University of Colorado at BoulderIt has been supported,in part,by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health under Award Number P2CHD066613+1 种基金Furthermore,this work has been funded,in part,by an Andrew Carnegie Fellowship(#G-F-16-53680)from the Carnegie Corporation of New York to D.BalkInnovative Seed Grant funding from the University of Colorado,support through Earth Lab,a University of Colorado Boulder Grand Challenge Initiative,as well as a development grant received from the University of Colorado Population Center(CUPC)at the Institute of Behavioral Science(University of Colorado Boulder),are acknowledged.
文摘There is an increasing availability of geospatial data describing patterns of human settlement and population such as various global remote-sensing based built-up land layers,fine-grained census-based population estimates,and publicly available cadastral and building footprint data.This development constitutes new integrative modeling opportunities to characterize the continuum of urban,peri-urban,and rural settlements and populations.However,little research has been done regarding the agreement between such data products in measuring human presence which is measured by different proxy variables(i.e.presence of built-up structures derived from different remote sensors,census-derived population counts,or cadastral land parcels).In this work,we quantitatively evaluate and cross-compare the ability of such data to model the urban continuum,using a unique,integrated validation database of cadastral and building footprint data,U.S.census data,and three different versions of the Global Human Settlement Layer(GHSL)derived from remotely sensed data.We identify advantages and shortcomings of these data types across different geographic settings in the U.S.,which will inform future data users on implications of data accuracy and suitability for a given application,even in data-poor regions of the world.
