Learn About Mapping and Geographic Information Systems

Written by Carly Hallman

map and compass

The field of geographic information systems, or GIS, is a relatively new area of study that combines maps and other types of data to present information about a specific region. The “geographic” part of its name refers to data that is geographic in nature, meaning a specific plot point on a map. These geographic data points can be as large as continents or as small as individual lots on a city street, as long as they involve a specific location. The most basic and widely understood geographic grid is latitude and longitude. When another type of data is applied to a map with latitude and longitude parameters, it becomes a GIS. For example, someone could create a GIS for a gated subdivision and its Internet use. Each house’s physical address would be the geographic data, and the information about each house’s Internet use would be tabular data. The Internet provider would then be able to produce maps that illustrate each house’s Internet use and determine who are the biggest users. Such maps are often color-coded, and additional data points may be featured in an overlay on the map.

What Is a GIS?

At its core, GIS is just a map with some data points overlaid on it. Every time you use Google Maps to search for restaurants, stores, coffee shops, or parks, you’re using a geographic information system. The geographic information is represented by the map and satellite data. Other data, such as the number of Chinese restaurants within a specific radius, is applied to the specified map in order to provide a clear picture of the region in question. The combination of map data and other data sets allows for a GIS to provide an analytical, data-driven map of anything from the amount of traffic on the roads to restaurant availability to current drought conditions. ESRI, or the Environmental Systems Research Institute, is the leading body for GIS.

History of GIS

At the core of GIS is cartography, or the process of map-making. Cartography has been an inexact science for much of human existence. The earliest maps were made by the Greeks. Sailors and explorers also charted much of the New World during the Age of Exploration, but their maps were imprecise and based on memory. It wasn’t until the invention of aerial cameras and satellites that we have been able to make precise maps of Earth’s terrain. Now that researchers and scientists have precise, scalable maps, they can overlay different data sets on those maps to produce a GIS.

Maps were something many governments often produced and still do, and as such, governments are some of the leading authorities on GIS. It was the Canadian Geographic Information System in the 1960s that saw the potential for combining cartographic data with tabular data. Early systems had to be created with hand-punched cards that were fed into an analog computer. Because of this time-consuming method, there was a push to further develop GIS technology. As computers become more advanced and powerful, more intricate and detailed maps can be created. Geographic information systems are much easier to create today thanks to high-powered computer processors and their availability to the general public.

How Does a GIS Work?

A GIS needs location and map data to function. This data can pertain to anything from a few city blocks to the entire planet. ZIP codes are one example of location data. Once you have the parameters of your location set up, you can overlay any tabular data you’d like. However, this involves building a database of information. Using a map of a subdivision, you could add data on Internet use, number of residents, number of cars owned, and the like. This data could be stacked in layers to create a full picture of the subdivision. Collecting the data is the tedious part of creating a GIS.

Uses of a GIS

The applications of a GIS are endless. We can already see the benefits of a GIS in programs such as Google Maps or anything that relies on location data for functionality. Climate scientists and researchers studying the effects of drought often use a GIS to illustrate the drought index and fire danger. Have you ever seen a map that illustrates the fire danger in degrees of yellow, orange, and red? That map was developed using geographic information systems. What about an electoral map on Election Night? Election polling and prediction is a major application of geographic information systems.

Glossary of Terms

As a highly specialized field, GIS has a number of words and phrases that may be unfamiliar to the average person. Geocoding is adding points to a map based on their street address or number. Raster data is spatial data that delineates space as equally sized units organized in columns and rows, similar to pixels. ArcGIS is a bundle of programs that aid in the creation and use of geographic information systems. Topography is the study of terrain and relief, while cartography is the science of making maps.

Careers in GIS

The field of geographic information systems is rapidly expanding, applies to a number of industries, and has tremendous potential for growth. Climate scientists and forest rangers use GIS to understand drought patterns and wildlife distribution. City planners and engineers collect a variety of tabular data and create maps that help roads and traffic lights operate more efficiently. Even the sewer lines running underneath our homes are organized using a geographic information system. All of the maps and computer programs that support GIS need to be developed, too, so CAD experts are also in high demand. The best thing about GIS right now is how quickly the field is growing, which means lots of opportunities for careers. Governments at all levels need people who can create a GIS to track any number of data points. Poll watchers consistently grasp for a greater understanding of their districts and need data collectors to populate their electoral polling maps. Wherever there’s a map in need of analysis, there’s a need for someone trained in GIS.

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