Boston University News Release
BU Geographers Develop New Way to Map Environmental Effects of World’s Urban Areas
(Boston, Mass.) — Using satellites rather than ships and pixels rather than paper, modern cartographers have pushed both the scope and technology of maps to produce images that move well beyond the simple detailing of boundaries. Today’s map makers produce regional, continental, and global portraits of Earth’s environment, images that detail the use, or abuse, of existing resources and the effects such actions have on populations near and far.
Recent research by a team of scientists at Boston University is setting new standards for modern cartography by building maps that fill an underserved need: images that detail the environmental effects of urban centers and their built-up surroundings. The researchers are developing accurate, up-to-date maps that will offer decision makers the tool they need to anticipate the long-range, global effects of city landscapes.
Developed by Boston University researcher Annemarie Schneider and her colleagues from the University’s Department of Geography and Center for Remote Sensing, the technique is reported in the December issue of Photogrammetric Engineering and Remote Sensing. The findings are from the first of a three-phase study. The study’s second phase will monitor how cities have changed during the past decade while the third phase will link land-use change information to the socioeconomic forces driving those changes.
“The results give us an idea of the extent of built-up land in areas that have not been mapped for many years, such as Africa,” says Schneider. “These maps will not only be useful to scientists studying energy transfer, hydrology, and climate interaction, but to social scientists trying to understand the land impacts of population and economic activity at a global scale.”
To build the maps, Schneider fused data from three data sets: NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS); 2001 population density; and the Defense Meterological Satellite Program’s (DMSP’s) Nighttime Lights. By fusing these data, Schneider not only enriched the amount of data from which she could build the maps but also accentuated advantages, and overcame disadvantages, inherent in any one set.
The team’s use of MODIS data to assess urban centers is the first such application of these data. MODIS data are gathered by NASA’s Terra satellite, part of the agency’s Earth Observing System project. The DMSP is a Department of Defense program that designs, builds, launches, and maintains satellites that monitor meterologic, oceanographic, and solar-terrestrial environments. Satellites that gather the Nighttime Lights data are designed to detect low levels of visible–near infrared radiance at night — from moonlit clouds to gas flares to lights from cities and towns.
Boston University’s Department of Geography emphasizes traditional geographic theory, quantitative techniques, and environmental and policy studies. Areas of faculty research include energy–environmental systems and resource analysis, geography of development, remote sensing and geographic information systems, and biogeography and climatology.
The University’s Center for Remote Sensing was established in 1986 as a facility for scientific research in the fields of archaeology, geography, and geology. The Center uses satellite images and other data from airborne and ground sensors to study Earth and its resources, particularly groundwater and land cover.
Boston University, with an enrollment of more than 29,000 in its 17 schools and colleges, is the fourth-largest independent university in the United States.
Note to editors: For images of maps and for additional information on this research project, please go to http://www.gsfc.nasa.gov/feature/2003/1212globalcities.html