In the first part of this three-part edition of the Geospatial Frequently Asked Question (G-FAQ), I analyzed the various definition put forth for GIS. Each of these definitions build upon each other, extending the meaning of GIS from software, to a social tool and finally to a science. In this second part of the ‘What is GIS?’ series, I pivot from an analysis of the various definitions to the development of GIS.
As a quick reminder, this series G-FAQ will focus on three core questions:
What is GIS: is it just computer software or is it a science? How did GIS develop into an established field of study? How does GIS work and what can you use it for?
The history of GIS can be divided into three basic phases. The first is the early roots of GIS where ‘pen and paper’ cartography moved from a static map to a collection of interactive spatial layers that could be viewed simultaneously. The second phase is marked by the advent and proliferation of the computer, and thus digital maps. The final phase is the ‘Golden Age’ of GIS, which we are in now, where digital mapping rapidly advanced as computers became faster, cheaper and ubiquitous.
The First Phase – Roots of GIS
The roots of GIS can be traced back to cartographic representations from the early 20th Century. Many scholars credit Ian L. McHarg (1920 to 1981) as the ‘Father of GIS.’ In 1954, McHarg accepted a position at the University of Pennsylvania in the Landscape Architecture and Regional Planning department. During McHarg’s time at U Penn, his research focused on fitting human-made structures into the natural landscape that surrounds them. McHarg was a pioneer in the use of clear acetate overlays to display multiple spatial layers at once with the ability to turn them on and off in a rudimentary fashion. Most of these maps started with a base layer of topography with overlays highlighting cultural and natural features as well as zoning regulations, development plans and more. Similar to what can be done in a modern GIS, McHarg would assign weighting values to each of the key features in his acetate overlays. By summing the weighted values, he was able to make relatively unbiased decisions to help in the plan and design process.
Another pioneer in map overlays was the British architect, Jacqueline Tyrwhitt (1905 to 1983). In her 1950 textbook, “Town and Country Planning,” Tyrwhitt first described the process of using matching scales in the overlays to assure the data lines up; and then McHarg extended this concept in his later research. In 1959, the famous geographer, Waldo R. Tobler (born 1930), conceptualized using computers to input cartographic information and produce accurate digital maps. Other examples of a rudimentary GIS include the wooden hinged maps used in the American Revolution to show troop movements; and the Irish Railway Atlas from the mid-1800s which showed population, traffic flow, geology and topography on the same paper map.
The Second Phase – Advent of GIS
The beginning of GIS is closely tied to the development of mainframe systems in universities and government offices as (obviously) a computer is required to map data digitally. GIS was ‘born’ during the 1950s and 1960s and grew alongside computers as they became faster and more powerful – opening up new avenues of digital analysis and on-screen display capabilities. When considering the advent of the digital mapping era, GIS was driven forward in different yet complimentary manners by the academic, government and commercial spheres. The second phase of GIS’ development stretches roughly from the late 1950s to the early 1980s.
As they usually are in the majority of sectors in which they are actively involved, academics are responsible for innovative approaches, research and merging technologies (i.e. statistics and cartography) as related to GIS. One of the leading campuses driving digital cartography forward was the University of Washington (UW), specifically the Geography Department, from 1958 to 1961. UW is generally attributed with advanced research leading to the quantitative revolution, whereby the fields of spatial statistics, computer programming and analytical operations were merged. In fact, Tobler was one of the most prominent UW researchers at this time. During the 1960s and early 1970s, the Laboratory for Computer Graphics at Harvard University developed many of the earliest digital mapping software packages, such as SYMAP, GRID and CALFORM. SYMAP, or the Synergraphic Mapping System, was one of the first developed in the 1960s by Howard Fisher. In 1962, the Massachusetts Institute of Technology (MIT) focused on creating weighted map overlays. A weighted overlay is one where each map layer is given a value that is tied to its importance, the higher the value, the more important the layer; though this weighting was not done in a digital fashion yet, rather it was completed as described above in McHarg’s research.
Government agencies were crucial to the early development of GIS as they took the lead on data standards and sharing; and they were often the earliest adopters of the technology. In the late 1950s, there are references to transportation planners creating digital maps of traffic flows, however it is unclear what software package(s) they employed. In the mid 1960s, the first widely-recognized GIS software was developed, the Canadian Geographic Information System. It was designed to map natural resources and inventory land, containing a variety of innovations such as the ability to vectorize data (i.e. to trace features and convert them to points, lines and polygons), append spatial attributes to features and then query for these attributes. In the United States, the 1970 US Census implemented a system for geocoding which assigned latitude and longitude coordinates to an address based on its estimated location along a block of properties. They also created the early version of TIGER files (i.e. Dual Independent Map Encoding, or DIME, files) which is a well known digital geographic database of road, rivers, railroads and other key features covering the entire USA. Oak Ridge National Laboratory played a major role in the history of GIS as they created a process to create digital data from scanned paper maps when they developed ORRMIS in 1969. Finally, two key government players were the US Army Corp of Engineers and the US military who developed a variety of raster processing capabilities, such as GRASS in 1982. There are also declassified military technologies that have made their way slowly into the commercial marketplace.
Once GIS took a foothold in the academic and government spheres, it was time for the commercial marketplace to bring the technology to the masses by making it more user-friendly. In 1969, Jack Dangermond opened Environmental Systems Research Institute (or Esri) and with it the commercial market for GIS was born. Initially, Esri used many of the innovations developed by Harvard Graphics as Dangermond was a 1969 graduate of the university’s School of Design with a master’s degree in Landscape Architecture. By the early 1980s, Esri developed software built around a relational database structure which is now the standard for all GIS packages. A relational database is one where information is organized in rows and columns as it would be on an Excel spreadsheet. By creating a relational database, you are able to index, query and perform analysis on GIS data in an efficient fashion. Starting with a single company in 1969, by 1976 there were at least 285 GIS programs on the market; and by 1980, there were more than 500!
The Third Phase – Golden Age of GIS
If any of you remember the 1980s, you might also remember the rapid proliferation of desktop computers in both the office and the home. And as computers had more speed, memory increased and prices dropped, cartography continued to move in the obvious, digital direction. Today, there is hardly a municipal government without a GIS department or at least a team of GIS professionals that assist with planning, mapping and much more. And as government agencies produce more free data, it has the synergistic effect of driving the GIS industry forward.
In the academic realm, nearly every major university and even many smaller liberal arts and community colleges offer a GIS degree or certificate. According to the Esri website, there are more than 1,300 campuses and extensions with licenses to their GIS software. Many GIS programs are now housed in geography departments. Academia still drives research forward and pushes the bounds of what is possible with GIS. They are also increasingly collators of free spatial datasets. A quick Google search finds more than 4,980,000 pages containing the term ‘GIS’; compare this with the much broader term, ‘Geography’, which finds 19,700,000 pages.
Commercially, the clear leader is still Esri, with more than 40% of the GIS market share in 2011. Pitney Bowes MapInfo is a distant second to Esri’s ArcGIS, although it is not clear what percent of the GIS market they control. As many of you might recognize, a large emphasis of recent ArcGIS releases are streamlining and usability improvements to the user interface.
It is clear that GIS has come a long way since the ‘early days,’ progressing from just a mapping software to a tool which can solve social, environment, academic and government problems. While GIS was developed as just a software package, it has its roots in what people think of as ‘science;’ and in that way, the two cannot be decoupled since GIS is a tool to make decisions, and science is used to make informed decisions. To give you a sense of the proliferation of ArcGIS alone, Esri estimates that more than 1 million people use their software every day!
In the third and final part of this G-FAQ series, we will explore what exactly can be done with Esri’s ArcGIS for those of you who are not academics or GIS professionals. I will also offer up my definition of GIS which attempts to bring together the disparate ideas presented in this series.
Do you have an idea for a future G-FAQ? If so, let me know by email at email@example.com.
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Brock Adam McCarty