Causes of Sprawl: A Portrait from Space
利用遥感数据测量美国城市蔓延程度，发现地下水、温和气候、崎岖地形、分散就业、早期公共交通、增长不确定性和未合并土地均会增加蔓延。
We study the extent to which U. S. urban development is sprawling and what determines differences in sprawl across space. Using remote-sensing data to track the evolution of land use on a grid of 8.7 billion 30 × 30 meter cells, we measure sprawl as the amount of undeveloped land surrounding an average urban dwelling. The extent of sprawl remained roughly unchanged between 1976 and 1992, although it varied dramatically across metropolitan areas. Ground water availability, temperate climate, rugged terrain, decentralized employment, early public transport infrastructure, uncertainty about metropolitan growth, and unincorporated land in the urban fringe all increase sprawl. Copyright (c) 2006 by the President and Fellows of Harvard College and the Massachusetts Institute of Technology..