All language subtitles for 03_what-is-a-gis.en

What is a GIS anyway?

Let's find out.

A GIS stands for
geographic information system.

And let me just stop here and
emphasize, as much as I possibly can,

that it is not a proper name.

So when you're using the full term in
a sentence, geographic information system,

it is not capitalized.

A lot of people want to because
the acronym, the short form of it,

GIS, is capitalized.

But when you're using the full
version in a sentence,

when you spell it out,
it is not capitalized.

Why am I going on about this?

Only because I think it's important
to pay attention to these details.

If you're new to this field and
you're going to be writing about it,

you want to look like you know
what you're talking about.

So every once in a while I'll point
out things like that, just so

it's clear that you know how to use
these terms correctly, that's all.

I'm not being super pedantic here,
maybe I am.

Okay, guilty as charged.

So GIS is an acronym, so it's capitalized,
and by the way, there's no periods either.

That's something that also people want to
include, is that when it's GIS, the short

form, no periods, and there are capital
letters, long form, no capital letters.

You get it, okay.

Just thought I would make that
clear because, seriously,

there is a lot of
terminology in this field.

I just want to make sure that
you're using it correctly.

So let's talk a little bit
about the history of GIS,

how did it start, where did it come from?

And it turns out that the very first
GIS was invented in Canada, so

yay Canada, yay, whoppee, whoo-hoo, yeah!

Okay, so let's start with a basic
obvious fact, Canada is big.

Yes, it is big, okay, got that.

So in the late 1950s and early 1960s,
the Canadian government began to

realize that they wanted to be
able to manage the use of land and

resources better for
economic and political reasons.

In 1962, the government decided
to map the entire country and so

started the Canada Land Inventory.

The plan was to create about 1,500
maps to cover the entire country.

And Roger Tomlinson was involved in
creating this Canada Land Inventory.

And so as he was planning this and
helping to direct

how this land inventory was going to take
place, he realized that there was two main

limitations to doing things the old
fashioned way with paper maps.

So remember, the idea was that they were
going to create 1500 paper maps that were

going to be an inventory
of the entire country.

So the first thing he realized was,
you can only fix so

much descriptive data on one map.

And by descriptive data,or if you think
information, that really is going to be

things like point symbols,
lines for things like roads or

areas that you're shading, or labels
that tell people what those things are.

And there's only so

much of that information that
can be packed into one map.

If there's too much, if you try to get
information on every single thing like

geology and wildlife and
census and farming data,

that there's going to be too much there
and it's not going to work very well.

So that was the first limitation,
is that there was a limitation to how much

data they could pack
into one map on paper.

The second thing was that it's
one thing to make a map like but

then it's another to then interpret or
analyze that map.

So even though people are very
good at seeing patterns on a map,

it's extremely time consuming to do
things like measure areas on a map or

compare different features that
might be on different maps.

Or then try to combine all of that
into some kind of complex analysis.

So this happened to be at the time when
computer development was really starting

to take off, so
you remember this was in the 60s.

And Roger Tomlinson recognized that and
wondered if there was a way that he could

use computers to solve this mapping
problem that he was having.

So Roger Tomlinson wrote a report
that described what he proposed

as a new computer system.

The purpose was to analyze geographic
data over any part of Canada.

To be able to input data in a variety
of ways, including tracing paper maps.

To organize the data so
it would be easy and efficient to access.

Combine and analyze data, to then of
course analyze that data including

measuring areas and creating overlays
of different geographic themes.

And then report the results of that
analysis as maps and/or tables.

So the team that he was on
started by talking about this

project as computer mapping.

But then they realized it would
be much more than that, and

they came up with the term Canada
Geographic Information System, or CGIS.

The system continued to be developed for
many years, and

Roger Tomlinson is now recognized as
the Father of GIS, quote, unquote.

So the Canada Land Inventory lives on,

you can still download data
from that inventory today.

So this is from the Government of Canada
Website for Agricultural and Agri-Food.

So if you want to access the data
that began all those years ago,

you still have access to it today.

In terms of describing what a GIS is, if I
meet somebody for the first time, say at

a party or something, and inevitably the
conversation somehow turns around to GIS,

just saying, I'm often amazed how
many people have heard of a GIS.

But if they haven't, the simplest way
that I can describe it is that it's

like connecting a database to a map.

If you have a database or a table full of
values like this, in and of themselves,

if that's all you had to work with,
they're not very easy to interpret.

If I asked you to look at this and say,

these are things like population density
in different parts of the United States.

If I said, well,
what areas have higher density and

which areas have lower density,

You'd have to scroll through all
of these columns and look at it.

And say, well I'm not sure what the highs
values are and I'm not sure what these

codes mean, what these IDs are,
where those are, where they're located.

But if we attach that data to a map, And

we take one of those columns and we color
code our map based on the information

in that column, suddenly we have
something that is easier to interpret.

So what we've done here, this is known
as a choropleth map, is that we have

created a legend where we have values that
are associated with different colors.

So the higher the population density,
the darker the value.

The lighter the population density,
the lower the value.

And so
you have the gradation from light to dark.

And it's very easy, well,
this is Central Park in Manhattan, so

there's low population there of course.

But then it's easy to see areas with
high population, low population, and

ones in between.

So that really is the power of mapping and
of a geographic information system,

is to be able to attach data to that map.

It really is like saying
a picture is worth 1,000 words,

as we can take not only 1,000 words,
but we can take 1,000 points of data,

or more, and turn it into a picture and
make it easy for somebody to interpret.

And that tells a story.

That's a way of communicating
information to somebody about something

that we're interested in.

When we are talking about what
the GIS is and how to define it,

one place to look for information
about what that is on esri's website.

And this is through resources.arcgis.com.

And I just want to draw your attention
to one part of the definition here.

They say a geographic information
system is a system used to describe and

characterize the Earth and
other geographies for

the purpose of visualizing and analyzing
spatially referenced information.

This work is primarily
performed using maps.

The purpose of GIS is to create,
share, and apply useful map-based

information products to support the work
of organizations, as well as to create and

manage the supporting
geographic information.

So visualizing and
analyzing are two key parts to a GIS.

Think of them as making a map, visualizing
and examining what's on the map, and

what that can tell us by looking at things
like locations of geographic features.

Whether there are patterns, or clusters,
or relationships with other variables, and

that part would be the analysis.

So what do they mean by
spatially referenced?

All that means is that we have a way
of accurately positioning something

within some kind of reference system.

So that could be something really
simple like a grid of squares.

It could be relative to anything.

It could be the corners of a parking lot,
and where is it in relation to corners?

For us, of course, usually it's
relative to the surface of the Earth.

And we have a whole coordinate
system designed for that,

it's based on position related
to the poles and the equator.

And we'll get into that
in another segment.

So I'm not going to go through
every reading in as much detail.

But I do think it's important that we
kind of highlight these some key concepts.

I would encourage you to read the rest
of that page to kind of get yourself

familiar with the terminology and some of
the basic ideas about these definitions.