Chapter 7 - GIS software

We begin a new section of the text that focusing on techniques for dealing with spatial information. As the ArcGIS exercises (and your assignment) take us deeper into GIS, Longley et al guide us through an extremely complicated world.

Even though you have been using GIS for a couple of weeks, it is useful to step back and consider the role the systems play in various organizations. Although ESRI is at the moment probably the industry leader (in terms of users and revenues), it is important to recognize that there are other environments in which to do GIS. In fact, I would prefer to teach this class with an open source (or at least cheaper!) GIS that you could continue to use after the license expires.

This chapter is an overview of both of history of GIS and of how GIS has evolved in two directions: on the Internet and into smaller personal "computers" Use this guide to insights if you don't read this chapter as carefully as you might want to; save your energy for Chapter 8!

7.1 Introduction

You may recall my arguing for the ancient roots of GIS in maps of any sort, but this chapter discusses digital GIS, and in fact that rarefied species of fully-featured software that only a few organizations have the scale to maintain reliably. Still, because you can use a spreadsheet to map a table of (X, Y) coordinates, I'd argue that even Excel can be used as a GIS.

7.2 The evolution of GIS software

It may help to organize the narrative of this section as a table:

1970s   GIS as unique programs
command line operations
1980s


 standard user interface
customization
calls from high-level languages
market-tailored applications
1990s web-based and -enabled
2000s GIS embedded in the web, devices

7.3 Architecture of GIS software

If the following sentence is a turn-on for you then by all means read this section carefully:
"...most sophisticated and mature GIS workgroups have adopted the client-server implementation approach by adding either a thin or thick server application running on the Windows, Linux, or Unix operating system."
Otherwise, I suggest skimming the section. But note from the various graphics the ubiquitous theme of hierarchy that organizes computers and GIS. And as the Internet grows in size and complexity, this hierarchy will only become more biological in its interconnectivity.

And especially examine Figure 7.7 for its use of graduated symbols to represent settlements in India; you'll do this in the assignment. This sprawling book is well-organized but only a hypertext version could allow us to navigate its various ideas and visualizations.

7.5 GIS software vendors

Although ESRI is big, there are other important players, some of whom are given the nod in this section. I think it unfortunate that Idrisi is neglected here as it probably has a bigger bang for buck than any other GIS on the market.

And I can't move on without recognizing the impossible-to-miss Scott Morehouse (Box 7.1) who is not only a GIS guru but obviously looks the part. (You might say he and Alan MacEachren (Box 13.3) were separated at birth...) These gentlemen are younger than they look, and GIS is even younger, so you can regard yourself as a late pioneer.

7.6 Types of GIS software systems

Although GIS began on what were once called "mainframe" computers, as with many other things, the personal computer has made GIS accessible to anyone with sufficient processing power. Yet I question whether in most cases anything more than a so-called "intelligent terminal" is necessary for many organizations. Do you need to have copies of the data on your PC, especially if all you're doing is viewing layers and assembling maps? These economies of scale are why this section argues for the comping primacy of "server-based" GIS.

I would go so far as to say almost all software and data do not need to be on the user's computer. Google is now storing "my maps" as well as documents and spreadsheets.

It's always interesting to review "historical" URLs such as those listed in Section 7.6.2:
No doubt you can find many others.

Task Find a few websites with environmental data by checking out a GIS resources page I created for a class.

Box 7.2-4 shows screenshots of  two non-ESRI GIS programs. Note how the first two show attribute and spatial data side-by-side and how each shows a legend/table of contents. Apparently there are only so many ways to visualize GIS data.

Figure 7.15 is obviously rendered obsolete by the explosion of Internet mapping, GPS on cell phones, etc. (I can't let the graphic pass without criticizing 3-dimensional bar charts (one of Edward Tufte's many peeves - think about it, what does the third dimension - i.e. depth - add to that chart?).

The final subsection demonstrates how GIS has migrated to the smallest devices that still enable you to see the map.