Developing a science of land change: Challenges and methodological issues

Departments of ^*Sociology and ^‡Geography, University of North Carolina, Chapel Hill, NC 27599; ^†Carolina Population Center, Chapel Hill, NC 27516-2524; ^§Graduate School of Geography and ^¶George Perkins Marsh Institute, Clark University, Worcester, MA 01602; ^**East–West Center, Honolulu, HI 96848; and ^††Demographic and Health Research Division, Macro International, Calverton, MD 20705

Edited by Susan Hanson, Clark University, Worcester, MA, and approved July 27, 2004 (received for review June 11, 2004)

Abstract

Land-change science has emerged as a foundational element of global environment change and sustainability science. It seeks to understand the human and environment dynamics that give rise to changed land uses and covers, not only in terms of their type and magnitude but their location as well. This focus requires the integration of social, natural, and geographical information sciences. Each of these broad research communities has developed different ways to enter the land-change problem, each with different means of treating the locational specificity of the critical variables, such as linking the land manager to the parcel being managed. The resulting integration encounters various data, methodological, and analytical problems, especially those concerning aggregation and inference, land-use pixel links, data and measurement, and remote sensing analysis. Here, these integration problems, which hinder comprehensive understanding and theory development, are addressed. Their recognition and resolution are required for the sustained development of land-change science.

Footnotes

↵ ∥ To whom correspondence should be addressed. E-mail: bturner{at}clarku.edu.
This paper was submitted directly (Track II) to the PNAS office.
Abbreviations: LCS, land change science; GISc, geographic information science.
↵ ‡‡ For example, the Land-Use/Cover Change effort of the International Geosphere-Biosphere Programme (IGBP) and the International Human Dimensions Programme on Global Environmental Change (IHDP) (www.geo.ucl.ac.be/LUCC/lucc.html); National Aeronautic and Space Administration Land Cover and Land Use Change (LCLUC) program (http://lcluc.gsfc.nasa.gov); and the forthcoming Global Land Project of the IGBP and IHDP (www.igbp.kva.se/cgi-bin/php/frameset/php).
↵ §§ Throughout, data problems refer to the attributes of the data relative to the theory, model, or problem to which the data are employed, such as scalar mismatches, not the issues of generating, archiving, and distributing data.
↵ ¶¶ The ability to assemble temporal depth rests on the quality and coverage of the images archived along with the maintenance of that archive. Unfortunately, aerial photos tend not to be archived internationally, or even nationally, except for some countrywide federal programs (e.g., the U.S. National High Altitude Program). In contrast, many satellite systems have associated archives that can be searched for suitable images to purchase. Problems exist, however, with retrieval equipment and archival maintenance, the loss of ephemeris data and associated header files vital for image corrections by international receiving stations, and omissions apparently abundant during the privatization experiment of Landsat products.