Featured Uses of Data

Researchers used observations of very small particulates in the air, as monitored by the U.S. Environmental Protection Agency as well as via the satellite-based Global Annual PM2.5 Grids from MODIS, MISR and SeaWiFS Aerosol Optical Depth (AOD), v1 data set distributed by SEDAC, to uncover the relationship between air pollution and type 2 diabetes. Controlling for non-pollution factors like obesity, they found that tiny particulates are responsible for a significant number of diabetes cases and that reducing exposure to the pollution would yield significant health benefits.

Using data from the NASA Gravity Recovery and Climate Experiment (GRACE) satellite instrument and the Advanced Land Observing Satellite Phased Array type L-Band Synthetic Aperture Radar (ALOS PALSAR) to study land subsidence, and SEDAC’s Gridded Population of the World (GPW), v3 to examine the distribution of people, investigators assessed the loss of groundwater storage in one of Mexico's most important watersheds.

Tornadoes account for about one in five natural hazard-related deaths in the United States.  This recent study investigated the relationships between tornado casualties (injuries and deaths), storm energy, and population using the NASA SEDAC Gridded Population of the World (GPW) v4 data set.  For all tornadoes, investigators found that a doubling of population increased the casualty rate by 21% while a doubling of storm energy increased the casualty rate by 33%.  For the strongest storms casualty rates from increases in population and storm energy were even greater.  These estimates can be used to project future changes in casualties given known population and storm trends.

SEDAC's Global Rural-Urban Mapping Project (GRUMP) v1 population and urban extent data are used in the International Food Policy Research Institute (IFPRI) interactive mapping application for Sub-Saharan Africa.  The application, known as Mappr, is built on IFPRI’s HarvestChoice geospatial database of biophysical and socioeconomic indicators covering four broad research domains: agriculture, agroecology, demographics and markets.  Mappr serves as the core to a decision-support system enabling people to visualize relationships between major agroecological challenges, like soil and land degradation, and socioeconomic trends such as poverty, health and nutrition.

For a new report assessing the environmental and socioeconomic conditions in 286 of the world’s transboundary river basins, SEDAC data were used in the calculation of several indicators: economic dependence on water resources, societal wellbeing levels, and the risk of climate-related hazards. The report is an outcome of the Transboundary Waters Assessment Programme, coordinated by the UNEP-DHI (Danish Hydrological Institute) Center on Waste and Environment in execution with international partners, for the Global Environmental Facility, with the aim of creating a baseline assessment of all transboundary water resources on Earth.

Combining SEDAC’s Low Elevation Coastal Zone (LECZ) data and Natural Disaster Hotspots flood frequency maps with land cover imagery derived from NASA’s MODIS instrument, the researchers who developed SEDAC’s Global Grid of Probabilities of Urban Expansion data set ask how the global and regional patterns of urban growth in the near future will affect urban susceptibility to floods and droughts.  What they found is that the extent of urban areas exposed to floods and drought will generally double by 2030, even without factoring in the potential impacts of climate change.

The SEDAC Global Agricultural Cropland and Pasture data sets are presented in Food: An Atlas, which uses maps to explore global food distribution and production.  The cropland and pasture data, originally developed by Ramankutty et al (2008), are transformed into cartograms, in which the land area of countries is replaced by extent of crops and pastures, by Benjamin Hennig to better visualize the magnitude of agricultural areas around the world.

A complex spatial relationship between population density and fire exists across the globe.  This study looked at this relationship by comparing population density data from SEDAC’s Gridded Population of the World to burned area maps based largely on NASA MODIS satellite observations.  In general it finds that in regions where climate or vegetation create conditions where fire is likely, people tend to suppress the fire, whereas in less fire-prone regions people tend to let the fire spread.  In most regions of the world, increased population density initially leads to an increase in burned area but that relationship reverses at higher levels of population density.

Carbon dioxide (CO₂) is the primary greenhouse gas responsible for warming the planet.  While the global distribution of carbon dioxide in the atmosphere is well known, tracking the emissions of CO₂ to their sources is a challenge, especially over large urban areas.  One approach uses the NASA instrument Measurement of Pollution in the Troposphere (MOPITT). Here scientists explore how carbon monoxide (CO) emission measurements from MOPITT can complement existing satellite CO₂ measurements in megacities delineated by SEDAC’s Gridded Population of the World, to provide improved spatial and temporal understanding of CO₂ emissions.

Human impacts have resulted in a global tendency for tree cover to be constrained to sloped terrain and losses to be concentrated on flat terrain. This effect, which the researchers quantify using NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) and Shuttle Radar Topography Mission (SRTM) satellite instruments, increases in strength with increasing human pressure, as measured by SEDAC’s Human Influence Index data set. It is most pronounced in countries with rapidly growing economies, limited human population stress, and highly effective governments, as defined in SEDAC’s Environmental Sustainability Index. By combining these measures of human influence with the remote sensing of trees, the researchers show how interactions between local topographic conditions and human impacts control tree cover distribution.

In moist regions around the globe, fire activity is believed to be driven by drought frequency, whereas in dry regions, fire is thought to be limited by the amount of fuel available.  Researchers recently tested these ideas by comparing global fire activity as detected by the NASA Moderate Resolution Imaging Spectroradiometer (MODIS) sensor with measures of vegetation such as net primary productivity from the Human Appropriation of Net Primary Productivity (HANPP) data collection available from SEDAC and the Normalized Difference Vegetation Index (NDVI) derived from NOAA satellite data.  Although fire activity is indeed limited by droughts in moist areas and by fuel in dry regions, human activities—specifically tropical rain forest deforestation and fire suppression policies in the western U.S.—also strongly influence fire activity.

A recent survey of African forest elephants has revealed a startling reduction in that animal's population and geographic range over the past decade.  Human population density, as measured by SEDAC's Gridded Population of the World (GPW v3) data set, and nearness to human infrastructure, as indicated by SEDAC's Human Influence Index (HII v2), are two of the strongest predictors of that decline along with hunting intensity, poor governance and absence of law enforcement.

The growth of urban areas has long been considered a local issue, but scientists using SEDAC’s Global Rural-Urban Mapping Project (GRUMP v1) and NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) land cover product have made spatially explicit forecasts of urban land-cover change to show that biodiversity hotspots and carbon pools will be significantly affected by urban population growth.  The researchers estimate that by 2030, urban land area around the globe will nearly triple the level in year 2000, resulting in substantial loss of habitats in key biodiversity hotspots.

An analysis of coastal wetlands loss from sea level rise due to climate change, conducted by SEDAC for the Ramsar Convention's Scientific and Technical Review Panel, provides estimates of wetland losses as a basis for identifying potential adaptation measures. The Ramsar Wetlands of International Importance: Sea Level Rise Impacts data and related map client make use of NASA’s Shuttle Radar Topography Mission (SRTM) elevation data, SEDAC’s Global Rural-Urban Mapping Project version 1 (GRUMPv1) population density grid for the year 2000 (and a 2010 projection), the GRUMPv1 urban extents grid, and an updated version of SEDAC’s Global Subnational Infant Mortality Rates, v1 data.

This article in the annual anthology, Sensing Our Planet: NASA Earth Science Research Features 2012, describes how economists have used night-time lights satellite data together with SEDAC human settlements data as a measure of economic growth, complementing traditional economic data. The researchers combined a dataset produced by NOAA’s National Geophysical Data Center from the Defense Meteorological Satellite Program (DMSP) with SEDAC’s Global Rural-Urban Mapping Project version 1 (GRUMPv1) Settlement Points to attribute economic activity to specific cities.  The researchers, including former SEDAC staff member Adam Storeygard, show that the night-time lights data enable cross-border and subnational assessments of economic activity.

Researchers interested in the sustainability of groundwater depletion used SEDAC’s Gridded Population of the World (GPW v3) population count data for 2000 to find that approximately 1.7 billion people inhabit areas impacted by groundwater stress.  More than half the people affected live in China and India.

A five-part article examines the implications of world population growth beyond seven billion; SEDAC's Human Footprint data shows where Earth been most impacted.

Satellite data offer a particularly valuable perspective on PM2—small particles deriving mostly from burning fossil fuels and biomass, which can harm human health—because ground instruments may be unavailable or offer limited information, as is the case in China. With that in mind, researchers at Columbia University’s Earth Institute and Batelle Memorial Institute have developed maps based on satellite data that depict annual PM2.5 exposure in all of China’s provinces.

The widely distributed 2010-2011 World Resources Report: Decision Making in a Changing Climate includes coastal population estimates from SEDAC′s Population Landscape and Climate Estimates (PLACE) data collection. The data includes both the percentage of and a country′s actual population living within 10 kilometers of a coastline, and is based on SEDAC′s Global Rural-Urban Mapping Project (GRUMP) population data set.

A Nature Climate Change article focuses on the milestone of world population passing the seven billion mark and the implications for climate change mitigation and adaptation. Maps featuring SEDAC’s GRUMP data set, describing populations at risk of climate change impacts, are featured on Page 3. The article also features interviews with former SEDAC project scientist Deborah Balk and SEDAC deputy manager Alex de Sherbinin. 

A map using SEDAC′s Gridded Population of the World data set to illustrate a discussion of population density and population growth, page 50 of the National Geographic Visual Atlas of the World (2009).

A map of SEDAC′s the Human Footprint illustrates the extent to which Africa′s land area is influenced by humans.

This interactive map tool and associated data set lets users map low-income areas having high-density populations that lack good access to nutritious food (“food deserts”). Census tract-level statistics for these areas may also be viewed. Satellite imagery provides an optional background in the map viewer. SEDAC’s U.S. Census Grids data are used as a key source for the tool.

SEDAC′s GPWv3 and GRUMPv1, along with MODIS and SRTM data, are used in a paper, “Modelling the Distribution of Chickens, Ducks, and Geese in China,” by D.J. Prosser et al, appearing in Agriculture, Ecosystems & Environment. Global concerns over the emergence of zoonotic pandemics emphasize the need for high-resolution population distribution mapping and spatial modelling. Because of a lack of livestock population distribution data in China, modeling the distribution of poultry is critical to studying emerging zoonotic pandemics. GRUMP population density and urban extents are predictor variables in the model in this paper.

An embedded Google Earth client in an article in Nature News shows the population count living within 75 kilometers of each of the world′s nuclear power plants. Population increases with circle size and color, from green (< 0.5 million) to red (> 20 million). The data and analysis were developed by SEDAC.

A map by SEDAC of the world′s malnourished illustrates an article in Nature News, “Food: The Growing Problem.” It makes the case that inability to purchase food rather than lack of enough is the reason for worldwide malnutrition. 

The SEDAC data set Low-elevation Coastal Zone (LECZ) is the basis for a set of national-level indicators of the total area and population in the LECZ circa 2000. Map 2.2 (page 94), Chapter 2 of the World Development Report 2010, Managing Urban Growth and Flood Risk in a Changing Climate in South and Southeast Asia.  

Data and maps compiled by SEDAC and the Center for Hazards and Risk Research are featured in a front-page news article in the New York Times (print version February 25) assessing the vulnerability of buildings in earthquake zones. “Where Shoddy Construction Could Mean Death” shows a map (top) that depicts the predicted number of deaths in Instanbul from a magnitude 7.5 earthquake, depending on the type of construction of the building. The second map (bottom) ranks the vulnerability of other urban areas in earthquake zones with more than one million people.

This interactive map shows the population missing as a result of the Haiti earthquake on January 28, 2010. Thousands of personal reports of loved ones missing were provided to Ireport, and this information was combined with SEDAC population data to create the map.

An interactive map shows impacts from the recent Haiti earthquake.

SEDAC population density data was used in a map of the Haiti earthquake.

SEDAC′s role in making climate change data freely available to the public is noted in a collection of articles on how scientists use Earth science data to learn about the planet.

In this blog for the Center Environmental and Security Program (ECSP), CIESIN deputy director Marc Levy talks with ECSP director Geoff Dabelko about using the Gridded Population of the World (GPW) data product to aid in combining population and geographic data.

The report on linkages between climate and migration, In Search of Shelter, is featured in a daily geography quiz of the public radio program, PRI’s The World.

A typically higher standard of living in urban areas compared to rural ones does not rule out striking disparities within cities. SEDAC data from its Global Poverty Mapping Project is used as the basis for this  map. Map 1.2, illustration for Chapter 1--Density, The World Development Report Online 2009.

A map of Burma, based on the SEDAC Gridded Population of the World (GPW) data product, reveals that coastal areas hit hardest by the cyclone in May 2008 were highly populated. (Areas in progressively darker shades of brown represent increased population.)

Map of Pakistan illustrating areas of escalating violence in the Punjab, the country’s most populous province.

Map of school-age children in earthquake zones illustrates an accompanying article: following the recent earthquakes in China, experts assess school safety and the vulnerability of children to earthquakes.

Map of China illustrates an article comparing the location of the Sichuan province earthquakes with population centers in China.

A CNN video newscast refers to a map of the path of Cyclone Nargis and the populations affected, in the worst natural disaster in the recorded history of Burma (Myanmar).

Sensing Our Planet: NASA Earth Science Research Features 2008 features an article on how SEDAC data was used for the 2008 Environmental Performance Index and other environmental assessments; CIESIN’s Marc Levy is interviewed.