What Kinds of information (data layers) should I Include in the base map?
The objectives of the study will drive your choice of data layers. The following types of data are commonly included: • political boundaries, such as states, counties, municipal boundaries, census tracts, townships, countries • transportation, such as streets, roads, railroads • water, such as rivers, streams, lakes, oceans • topography and elevations You may want to include other basics related to your study, for example, schools, local parks, land cover or land use, trails, EPA toxic emissions sites, etc. 4. What scale, or resolution, should I use? Small scale data such as 1:1,000,000 are useful for looking at patterns on a global or continental extent. Large scale data, such as 1:1200 or 1:2400, are wonderful for looking at a neighborhood or town. You wont always be able to match perfectly the resolution of the base map to the purposes of your study and the extent of your study area, but do make some effort to do so. 5. Where shall I obtain the data for my base map? • Ideally, you w
