Using Online Satellite Imagery as a Research Tool Mapping Changing Patterns of Urbanization in Mexico

Research on urbanization in developing-countries is often complicated by a lack of data. Recently available online interfaces with maps and satellite imagery provide a potential source of up-to-date, free, and easy-to-use geographic information. This article evaluates one of these interfaces, Google Earth, as a tool for collecting data, illustrating the evaluation with two methodologies developed to study urbanization in Mexico. The first, used to collect data on road paving and housing density in informal settlements in Tijuana, is deemed successful, while the second, used to generate data on recent urban expansion in several Mexican cities, is not. The problem with the second methodology and primary limitation of the online tool is that satellite image data is presented without clear dates. Thus, its usefulness is determined by the time frame of analysis - as the period of time gets shorter, the uncertainty surrounding the end date becomes increasingly problematic.