Data Formats - Desktop GIS: Mapping the Planet with Open Source Tools - page 83

creating a logical structure for storing your data. For example, if all
your vector data is in shapefiles and you can create a nicely organized
directory structure, be it by theme or by project, then your ability to
find and use the data you need increases.

Some find that data management is improved by using a spatial data-
base, although there are perhaps better reasons to use one. By stor-
ing your vector and/or raster data in a spatial database, you pro-
vide one point of entry for all your data needs. There is no question
of which server or directory you need to search to find the data you
need. We'll look at spatial databases in more detail in Chapter 7 , Spa-
tial Databases, on page 98 .

Another example is GRASS, which uses its own format for storing both
raster and vector data. Data in GRASS is organized by location and
mapset, making it easy to structure your data collection in a way that
can be more easily managed.

Is improved data management alone a reason for converting to a par-
ticular format? Probably not, especially if you're talking about convert-
ing between file-based formats such as shapefiles and GeoTIFFs. The
chief considerations are making the data discoverable, accessible, and
usable. If your formats of choice include file-based data, you should
create a structured logical directory layout and naming convention and
adhere to it. This will make managing your data much easier and pre-
vent the multiplication of duplicate data sets. Another important man-
agement tool is metadata that documents each of your datasets. If you
want to take the formal approach and create metadata in a format that
others will understand, use the standard. 4 At the very least, you should
include a text file describing the data, its origin, and the processing
steps used to create it. Fortunately, the metadata standard includes all
these components, so you may find it's worth using.

Improved Functionality
If you want to do more than display and edit spatial data, then conver-
sion to gain improved functionality is certainly a worthwhile consider-
ation. For example, although QGIS is great at displaying a wide range
of raster and vector data and is even able to digitize and edit features,
it lacks the ability to perform common GIS operations. Harrison's sim-
ple analysis of bird sightings using a buffer (Figure 1.3 , on page 19 )

4. http://fgdc.gov/metadata