User Profile: Deborah Balk
Who uses NASA Earth Science Data? User Profile
Deborah Balk, Professor, Baruch School of Public Affairs, City University of New York (CUNY) Graduate Center Doctoral Programs in Public Health, Sociology, and Economics. Balk also is the Associate Director, CUNY Institute of Demographic Research.
Research interests: Urbanization in the developing world, including demographic behavior such as urbanization, fertility, and mortality (and related characteristics such as poverty). Balk’s research uses a spatial framework to study the demographic impacts of climate-related hazards and adaptations to climate change.
Current research/work focus: Most of Balk’s research is global, with a strong focus on Asia, Africa, and Latin America. Balk and her colleagues are working to create new, demographically informed methods to forecast city growth, both spatially and demographically. Balk also is looking at the determinants of spatial population change across scales, and examining if the factors that lead to changes in urbanization rates at the national level are the same as those driving city-growth throughout the rural-to-urban continuum. In a project with NASA’s Jet Propulsion Laboratory, Balk is examining change in megacities in perspectives ranging from the geophysical to the demographic to characterize urban change vertically and horizontally.
Data Products and Tools Used: Data sets from NASA’s Socioeconomic and Data Applications Center (SEDAC) at Columbia University, including:
- Gridded Population of the World (http://sedac.ciesin.columbia.edu/data/collection/gpw-v3)
- Global Rural-Urban Mapping Project (http://sedac.ciesin.columbia.edu/data/set/grump-v1-urban-extents)
- Shuttle Radar Topography Mission-derived data (http://sedac.ciesin.columbia.edu/data/collection/lecz/sets/browse)
Additional data sets include:
- Scatterometer data from QuikSCAT (https://winds.jpl.nasa.gov/missions/quikscat/)
- National Oceanic and Atmospheric Administration (NOAA) Defense Meteorological Satellite Program nighttime lights and Visible Infrared Imaging Radiometer Suite, which are available through NOAA’s Earth Observation Group (http://ngdc.noaa.gov/eog/)
- Global Human Settlement Layer from the European Commission’s Joint Research Centre (https://ec.europa.eu/jrc/en/scientific-tool/global-human-settlement-layer)
Research findings: Balk and her research team found that coastal zones are disproportionately urban. While 1 in 10 persons globally live in Low Elevation Coastal Zones (contiguous areas along a coast less than 10 meters (32.8 feet) above sea level) and thus are at greater risk of climate-related seaward hazards, 1 in 8 urban residents live in these zones. These ratios are much higher in Asia, where almost two-thirds of urban settlements with populations greater than 5 million occur in these zones. Climate change in these coastal settlement areas could lead to disasters that can be mitigated through a combination of migration and settlement modification.
In work on urbanization using satellite data to define urban extents in combination with demographic data, Balk found that city growth is driven by fertility, and that small cities are growing at much higher rates than large cities. Furthermore, cities are no longer effectively defined by an urban-rural dichotomy. By combining demographic and satellite data, urbanization is much better described as a continuum that incorporates peri-urban growth, the emergence of large urban agglomerations, and the development of small towns with urban characteristics.
Balk also is examining the impacts of urban growth and its impact on freshwater availability. By 2050, almost 1 billion people will live in cities with perennial water shortages. At this point midcentury, climate change rather than demographic factors will cause water shortage for an additional 100 million people living in urban areas.
Read About the Research:
Balk, et al. 2014. “Coastal Demography: Distribution, Composition, and Dynamics.” In Bowen, R., et al. (eds.), Oceans and Human Health: Implications for Society and Well-Being. New York: Wiley Blackwell: 49-70.
—. 2013. “What is urban? Comparing a satellite view with demographic & health surveys.” Available online at 10.1111/j.1728-4457.2013.00610.
—. 2011. “Urban growth, climate change, and freshwater availability.” Available online at 10.1073/pnas.1011615108.
—. 2009. “Mapping urban settlements and the risks of climate change in Africa, Asia, and South America.” Available online at www.iied.org/pubs/pdfs/G02650.pdf.
—. 2009. “Observations of urban and suburban environments with global satellite scatterometer data.” Available online at 10.1016/j.isprsjprs.2009.01.004, 2009.
—. 2007. “The rising tide: assessing the risks of climate change and human settlements in low elevation coastal zones.” Available online at 10.1177/0956247807076960.
Last Updated: Apr 25, 2019 at 2:02 PM EDT