Super-Maps Chart New Courses for Better Lives

In another century, Ross Martin might have sailed the oceans, scaled mountains, braved hostile continents and discovered new worlds.

In this one, Martin and the other members of San Diego County’s Geographic Information Systems (GIS) — like those explorers of old — make maps. They just do it sitting comfortably in front of computer screens.

But don’t be fooled by the ergonomic chairs, or even the term “maps.”

Cartography may have cut a more romantic swath in other epochs, but Martin, and every one of us, are living through the golden age of mapmaking — or ”super-mapmaking” — thanks to the computerized science of GIS that started roughly 45 years ago.

Maps used to tell us how to get from one place to another, or what another place looked like.

GIS maps can explain how the world works.

Called “super-maps” by many, they stack, or “overlay,” maps with different and varied information on top of each other, and use thousands of mathematical formulas to analyze reams of data and create pictures of what has been, what is, and what may be.

And Martin, the County’s GIS Manager, his co-workers and the County use them every day to improve service to the public: To make sure the closest Sheriff’s patrol or ambulance answers a 9-1-1 call. To find the best way to deliver health and social services. To help create a land-use plan that seeks to intelligently balance growth by putting portions of it closer to existing roads, fire and Sheriff’s protection, sewer systems and other infrastructure. To quickly relay information to the public when disasters strike. Or to track and fight crime or a public health problem like whooping cough.

“There are no degrees of separation,” Martin said. “There’s GIS and there’s direct public good.”

GIS is used by government agencies, academics, businesses and even the public to answer all manner of questions.

Some have called GIS “mapping on steroids.” Martin prefers the image of marrying mapping with high technology. Sort of like Ptolemy meets Captain Kirk.

GIS, Martin said, has three distinct parts:

  • A way to pictorially represent information — maps and visual imagery, whether that’s in print, a digital image on a computer screen, or even 3D imagery like Google Earth.
  • A means to store data — a computer database.
  • An analytical engine — formulas to analyze data and shed light on and explain statistical relationships.

Each of the three pieces is important. To create the core levels of database information, the region’s two largest governments, the County and City of San Diego, joined forces and created SanGIS. Martin said the SanGIS datasets include all kinds of information, such as parcel numbers and addresses, general plan information, neighborhood boundaries, special districts, fire stations, vegetation areas, reservation lands, hydrologic basins, schools, and agriculture commodities information.

Martin said the SANGIS databases form the 26 “base-map layers” that the County GIS uses. From there, GIS technicians can stack hundreds of additional layers of new information from federal and state resources, and other groups and agencies on top, “like pancakes … up to the roof.”

Then formulas such as regression, a forecasting model that measures how one thing changes if other independent variables change, can analyze the data and produce whole new sets of data.

One map can show the numbers of whooping cough cases in the County over a period of years. A second overlay can show rates of whooping cough immunizations over that time.

A third can illustrate the effects of the interacting data. What happens to whooping cough incidents when immunization rates rise or fall?

More layers, more information. Are whooping cough incidents higher or lower in areas where immunization clinics are offered? Do whooping cough numbers increase or decrease based on the number of clinics?

Of course, the map — the picture — is the key. You can stare at tables of data and not see connections. But a map makes them visual and immediate.

A picture really is worth a thousand words.

Martin said the process is exciting, and while he and other GIS practitioners may not be scaling mountains or sailing the seas, they share a common link with those old-school adventurers.

“There is literally, in the eyes of some of these employees who are working on projects, — you can see it — the joy of exploration,” he said. “They’re getting at something that people don’t really know. That’s discovery. And that’s interesting, because you’re making a difference and you’re going places no one has been.”

For more information, see the County of San Diego Public Web Map Gallery, and







Gig Conaughton is a communications specialist with the County of San Diego Communications Office. Contact