ABSTRACT
Although significant progress has been made recently to assess the distribution of human population with respect to physiographic features — coastline, rivers, elevation (Small and Cohen, 2004) — these estimates cannot distinguish urban from rural areas. Considerable unmet need for global delineation of urban areas, as well as unmet need for spatial estimates of urban population (Montgomery et al., 2003), led to the design of the Global Rural-Urban Mapping Project (affectionately known as GRUMP).
