About GIS and its Uses

Southside Planning District Commission uses Geographic Information Systems (GIS) to produce maps (paper, pdf (static), and interactive webmaps), mapping data, and analysis from mapping data.

A GIS system utilitizes some type of geographic database (a shapefile of Census blocks, or a layer of road centerlines, for example) that is joined with a database (such as an Access database containing the actual Census data). GIS can be used for many geospatial applications, including demographic mapping, 911 mapping systems, analysis, redistricting, gps mapping, and online interactive webmaps.

The GIS at SPDC is used to produce mapping products and services for many functions. We provide GIS services to all three of our member localities, including 911 map support and addressing technical support. We provide parcel mapping to 2 of our counties, and we administer the county-wide online GIS map for 2 of our counties. (See our GIS Services Section for more information on our services.) Internally we use GIS to support our grant application and administration processes, planning projects, and we use GIS mapping for other tasks as requested.

GIS Project Deliverables

Most GIS projects undertaken at SPDC result in any number of the following deliverables:

  • interactive webmaps (similar to Google Maps)
  • cartographic maps (paper and electronic, typically PDF)
  • GIS data (ESRI geodatabase, shapefile, KML, etc), or
  • spreadsheet/table data (Excel, Access)
  • analysis/information based on mapping

GIS Data

GIS data used by SPDC GIS staff typically is either created in-house using some type of digitizing process, or is obtained from outside sources such as the Commonwealth of Virginia or one of the Counties. Very rarely do we obtain GIS data from commercial sources. As much as possible, we strive to share data with others as we benefit from those that share GIS data with us. Now that we provide GIS services to our counties, our GIS data for our localities is more accurate and up-to-date than ever.

GPS Mapping

GPS (Global Positioning Systems) Mapping is accomplished by using a survey-grade GPS RTK system. Under ideal conditions this system has accuracy of up to a centimeter. We use it to obtain geospatial data primarily for mapping utility systems and transportation infrastructure. 

More Information

More information about GIS can be found at the following links:

ESRI - What is GIS?

GIS Lounge - What is GIS?

Wikipedia - Geographic Information System