Demographic information is usually provided on a national basis. But we know that countries are ephemeral phenomena. As an alternate scheme one might use ecological zones rather than nation states. But there is no agreement as to what these zones should be. By way of contrast, global environmental studies using satellites as collection devices yield results indexed by latitude and longitude. Thus it makes sense to assemble the terrestrial arrangement of people in a comparable manner. This alternative is explored here, using latitude/longitude quadrilaterals as bins for population information. This data format also has considerable advantage for analytical studies.
The report is in three parts. Part I gives the motivation and several possible applications. Ways of achieving the objective include, among others, simple centroid sorts or interpolation. In Part II the results to date are described. The estimated 1994 population of 217 countries, subdivided into 19,032 polygons, are being assigned to latitude/longitude cells. The estimated number of people in these countries is 5,617,519,139, spread over 132,306,314 square kilometers of land. Part III describes needed extensions. By reporting population in units of one tenth of a degree for the entire earth we have data which is two orders of magnitude finer than has previously been availabe.
The project has been funded by the California Space Institute, The Consortium for International Earth Science Information Network, the Environmental Systems Research Institute, and the National Center for Geographic Information and Analysis. Project staff include Uwe Deichmann, Jon Gottsegen, Kelly Malloy, and Waldo Tobler.
Waldo Tobler
Dept. of Geography
University of California
Santa Barbara, CA 93106-4060
Telephone: 805-964-0116