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Okay, so that is two words down—system and information.
That just leaves us with one more word to consider—geographic.
We have this very general idea of what it means for something to be
an information system, but we are not dealing with just any kind of information
here. We have this modifier "geographic".
Now, if you have already heard my lecture on "What is Geography?"
then you already have a pretty good idea about what geography is,
and what it must mean for something to be geographic. We said that the first
question geography asks is "where?" and then talked about other
questions geography asks as well. We also said geography is
ultimately about the holistic and comprehensive understanding of place.
Therefore, in a general sense, we might expect geographic
information systems to help us understand where things are
and then help us get to a holistic and comprehensive understanding
of that place. All of that is true, broadly speaking, but I
need something to go here—in this blank before "data". I can't
just put in "geographic" because that word is in what I am trying to define.
I need another word. Could I put the word "spatial"
in this blank? Just as I previously drew attention to the
distinction between information and data, here I want to consider the
distinction—if any—between the terms "geographic" and "spatial".
Are the terms "spatial" and "geographic" synonyms?
Well, I think not. What is the difference between something that is
spatial and something that is geographic? It is true that you sometimes
here these two words being used as if they are synonyms, but
there is an important distinction that needs to be made, especially if you are working in GIS.
While in an overarching sense, both "spatial" and "geographic"
are concerned with locations, and the relationships between objects
that are occur because of their location, I think "geographic" is a much
more narrow term than "spatial". Lots of people are concerned with
spatial information. Take engineers for example. When
they build something like an engine, they must be concerned with the spatial relationships
between all of the parts. Communicating the spatial relationships
between all of them is an important component of communicating how to
build the engine. It is not enough just to have all of the parts, they have to go
together in a certain way. Perhaps you have heard of computer aided design programs.
They are used by engineers to help them design objects
and they certainly must take space into consideration. This is also the case with
architects. When designing a house, office building, or a church,
architects need to be concerned with space and spatial relationships.
Even interior designers are concerned with the spatial arrangement of objects
in rooms in order to make it aesthetically pleasing as
well as functional. If you are online buying furniture for your apartment or dorm
or living room, you can sometimes use an app right there on the website
to help you arrange little pictures of the furniture you are thinking about buying
to see how they will fit into the room before you buy. In all of these
situations, people are concerned with spatial relationships.
Computer systems designed to help with any of these tasks must take
space into consideration. Even though all of the above are spatial,
they are not geographic. Being geographic has something to
do with the scale that is being considered. We could talk about this at great length,
but generally speaking, we can say that geographic things
are "big". The objects on your desk have spatial relationships
with one another, but they do not have geographic relationships.
When you look out the window of an airplane and see lakes, mountains, rivers
and hills stretching out all the way to horizon, these things have spatial
relationships, but more specifically, they have geographic
relationships. This issue of scale is important because of
the specific issues that geographic information systems must take into
to consideration, and that GIS users must be concerned with
that the users of other spatial information systems may not need to
consider. Generally speaking, a spatial information system
becomes a geographic information system, when the areas that it
considers are large enough that we at least potentially have to begin to
account for things like the curvature of the earth. The earth is not flat
and we have to take this into consideration. The fact that the earth is
spherical can have a tremendous impact on analysis and so the design of GIS
software systems must take this into consideration.
Have you ever had someone jokingly ask you, "What are you doing? Taking
into account the curvature of the earth?" When you're paying what they think is too much
attention to detail on some task? Well, in geographic information
systems, though, that is not unnecessary detail. That's
a foundational component. We take the curvature of the earth into consideration
in much of the analysis that we do. I realize that when
exactly an area become large enough that we need to start
taking into consideration the size and shape of the planet may be a bit
vague and it may vary a bit depending on what particular kind of analysis
you're trying to do, but I still think it is a very useful component
for our definition in order to distinguish geographic information systems
from general spatial information systems
such as those used for computer aided design.
So in this sense, all geographic things are spatial, but not everything
spatial is geographic.
Also, I want to point out that geographic information systems are generally
concerned with information about phenomena
that are taking place on or near the surface of the earth. Again,
what it means for something to be near the surface of the earth
can be left a bit vague for our purposes. People use GIS to
study subsurface geologic structures, and it is also very common
for people to use them to store atmospheric information so they can study
the weather and the climate. Similarly we can use GIS to study
oceans and oceanography, but I like to say that generally we are talking about
studying phenomena on or near the surface of the earth
at a scale that the size and shape of the planet is potentially
relevant. So if we put all of this together, we get
"a set of connected computer hardware and software, forming a
more complex whole, for the input, storage, retrieval,
display, processing, and/or transmission of spatially
referenced data about phenomena at the surface
or near the surface of the earth, at a scale that they size and shape
of the planet it potentially relevant." This is a much better
definition than simply saying that a geographic information system is
"an information system for geographic information", even given the
bit of vagueness about the size of the area being considered, or about
what exactly it means to be near the surface of the earth. I like
having a definition like this because it really does prompt you to think about
all of the things a GIS can be. Some people use a much
narrower understanding of geographic information system so that only
certain specialized computer applications count as GIS.
I do not take this approach. I think the field is much more expansive
than that. Think about some very commonly used lighter weight systems
such as Google Maps, or Google Earth, or even maps like
Yelp or Urban Spoon that are concerned with delivering geographically
referenced information. These systems qualify as geographic
information systems. Certainly some have much more functionality than
others, some have more tools. Some have more processing capability
than others. Some may even have different kinds of data to be
input and retrieved, and some may place restrictions on what a particular
user is allowed to do with with system, or what data he or she is allowed
to upload. For instance, Google Maps typically does not let a user
upload and change the road data. They are restricted in that area, but
data can certainly be input into that systems if you are one of the Google Maps
software engineering team. Limiting functions by role like that
is no problem for the understanding of GIS that I am putting forward here.
Finally, I would like to take a brief moment to focus on the "geo"
part of "geographic information systems". "Geo", of course,
means "Earth" and most of the instruction in a geographic information
systems course focuses on the earth, but it doesn't have to.
Many of the techniques and methodologies that are learned in a class
in geographic information systems can be readily applied to
other planets. Maybe you develop a great interest in the techniques
and methods of GIS, and get really involved in the kinds of questions
it will allow you to answer or problems it will allow you to solve, it is just that
you think the earth is boring and you would much rather work on something
else. That is no problem. You can take all of these techniques and methods and you can apply them
to a different planet. You can do the same kinds of
analysis on the moon or Mars or Venus or Jupiter
and there are geographic information systems that are specifically set up for the study
of other planets, because the techniques and methods, from a technical
perspective, are immediately transferable. Now, I don't know if we'll
come up with another word other than "geo"graphic information systems
for these kinds of systems that do this kind of analysis but for other planets,
or if we'll just retain the word as sort of historic legacy
as we move on to the study of other planets, but here
I am not terribly concerned about that. We'll continue to be somewhat
earth-centric in this course and in others in geographic information
systems, but if you want to take all of this knowledge and apply it to other
planets, that is no problem at all.
Okay. So much for the definition of geographic information system.
I am going to do a few software demonstrations, but before I do,
I want to briefly go over a few other terms that one commonly
encounters when studying geographic information systems. So that's what
we'll move to, next.
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