Digitizing in GIS is the process of converting geographic data either from a hardcopy or a scanned image into vector GIS data by tracing the features. Explained in this article are the types of common digitizing errors found when creating geographic data within GIS.
I do pro bono GIS work from time to time, and a recent contribution was towards a local school that was undergoing a capital campaign … Read more
After a lengthy battle in the court system, California’s Supreme Court has finally ruled in favor of allowing public access to the government’s GIS data in Orange County. Back in 2007, the Sierra Club sued the county for the right to use its GIS data for environmental mapping projects. Orange County resisted, however, claiming that the digital maps did not fall under the Public Records Act.
FEMA has been constantly updating and maintaining its Flood Hazard Mapping Program in order to provide ongoing flood risk assessments.
John Snow’s well known cholera map is often cited as one of the earliest known examples of using geographic inquiry to understand a health epidemic although his famous dot map was actually created after the cholera epidemic to show disease clusters. Â
There are two components to GIS data: spatial information (coordinate and projection information for spatial features) and attribute data. Â Attribute data is information appended in … Read more
Looking for global GIS data? Listed here are free sources for finding GIS data in both vector and raster formats including satellite imagery. Natural Earth … Read more
Those that work in GIS data have probably heard the phrase “80% of data is geographic”. What is the origins of this phrase, and is it true?
SDTS stands for Spatial Data Transfer Standard.  SDTS was a standard for transferring earth-referenced spatial data across disparate computer programs.  The U.S. Geological Survey (USGS) released SDTS … Read more
This article provides a brief overview of the GIS data collection process along with examples of methodologies for GIS data capture. Pre-processing Data in GIS … Read more
The U.S. Department of Agriculture has released a new Plant Hardiness Zone Map (PHZM). The map is the first updated in over twenty years and incorporates greater accuracy and detail since the last map from 1990.
