Chapter 23
Ten GIS Data Sources
In This Chapter
Getting data from government sources
Exploring clearinghouses
Finding commercial sources
The driving force behind all GIS analysis is data. GIS data come in many forms, from many sources, for many uses, with many scales and levels of accuracy, in different datums and projections, and at a huge variety of prices. Depending on your application and your specific needs, you may want to develop your own datasets. Developing your own datasets allows you to have total control over the content and accuracy, not to mention the ownership, of your data. Industry experts have claimed that data conversion (creating digital databases) often accounted for as much as 60 percent of the cost of system development. Large operations faced an enormous cost. Although these percentages have decreased over the years, they are still a substantial portion of the cost of operating a GIS. And so you might want to examine the possibility of obtaining datasets that already exist.
The sections in this chapter give you an overview of some handy GIS data sources, and Table 23-1 outlines their important features. While you’re evaluating sources, here are some questions that you can ask yourself to help you determine which tool you want to use:
Does your GIS have metadata management tools?
Do you need a tool that supports content standards (specifically the Content ...
