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How Does GIS Represent Real-World Items?
GIS isn’t a development that just popped up over the last couple of years.
Large-scale mapping efforts were done using computer-based cartography in
the 1950s and 1960s by a number of different government agencies and other
labs (including Harvard Laboratory). The term “GIS” first appeared in the same
time period of the early 1960s with the implementation of “CGIS” (the acronym for the “Canadian Geographic Information System”), which was designed
to provide large-scale mapping of land use in Canada. The development of CGIS
is attributed to Roger Tomlinson, who has become known as “the father of GIS.”
GIS developments have continued over the years through the efforts of government agencies and the private sector, until the current time when GIS technology and concepts are extremely widespread (see Hands-on Application 5.2:
ArcGIS Online, page 102, for another example of using GIS concepts online).
How Does GIS Represent Real-World Items?
GIS has a multitude of applications, ranging from mapping natural gas pipelines to determining which sections of natural land are under the greatest
pressure to be developed into some sort of urban land use. No matter the application, the data (such as the locations and lengths of pipelines or the area
and extent of land cover) needs to be somehow represented within the GIS. In
this sense, GIS provides a means to represent (or model) this data in a computer environment so that you can analyze or manipulate the data. A model
indicates some sort of representation (or simplification, or generalization) of
There are numerous online GIS resources for viewing
and analyzing spatial data. Search on the Internet to
see if your county or local government has any online GIS resources or a GIS mapping Website set up.
An example of a local GIS is from Mahoning County,
Ohio. Open your Web browser and go to http://gis.
mahoningcountyoh.gov and then select the option for Map Viewer. In the upper left-hand corner
of the screen will be the Property Search functions,
allowing you to search for a parcel of land by Parcel
Number, Owner Name, or Address.
Do a search for parcel ID: 29-042-0-002.00-0
(this is the parcel number for the Boardman Township Park). The map will zoom to the parcel of the
park. In the lower left-hand corner of the screen are
a series of available layers. Place a checkmark in
the box of the most recent available Ortho Photos
(under the Imagery heading). Click on the Refresh
button on the toolbar to see the results of adding
that layer (that is, high-resolution aerial photos of
the park). Select some other layers to examine,
and then refresh the map (by pressing the Refresh
button) to examine that data. Use the tools on the
toolbar (the magnifying glass to zoom in or the hand
to pan around the map) to get a closer look at the
map and the surroundings of the park.
Check your local state or county government’s
Websites to see if an online spatial data viewer (or
GIS) has been set up for your area. It may be part
of your county auditor’s Website or a separate GIS
department for the state or county.
Hands-on Application 5.1
Using GIS Online
CGIS the Canadian
Geographic Information
System — a large land
inventory system used
in Canada and the first
time the name “GIS”
was utilized for this
type of system.
How Does GIS Represent Real-World Items?
GIS isn’t a development that just popped up over the last couple of years.
Large-scale mapping efforts were done using computer-based cartography in
the 1950s and 1960s by a number of different government agencies and other
labs (including Harvard Laboratory). The term “GIS” first appeared in the same
time period of the early 1960s with the implementation of “CGIS” (the acronym for the “Canadian Geographic Information System”), which was designed
to provide large-scale mapping of land use in Canada. The development of CGIS
is attributed to Roger Tomlinson, who has become known as “the father of GIS.”
GIS developments have continued over the years through the efforts of government agencies and the private sector, until the current time when GIS technology and concepts are extremely widespread (see Hands-on Application 5.2:
ArcGIS Online, page 102, for another example of using GIS concepts online).
How Does GIS Represent Real-World Items?
GIS has a multitude of applications, ranging from mapping natural gas pipelines to determining which sections of natural land are under the greatest
pressure to be developed into some sort of urban land use. No matter the application, the data (such as the locations and lengths of pipelines or the area
and extent of land cover) needs to be somehow represented within the GIS. In
this sense, GIS provides a means to represent (or model) this data in a computer environment so that you can analyze or manipulate the data. A model
indicates some sort of representation (or simplification, or generalization) of
There are numerous online GIS resources for viewing
and analyzing spatial data. Search on the Internet to
see if your county or local government has any online GIS resources or a GIS mapping Website set up.
An example of a local GIS is from Mahoning County,
Ohio. Open your Web browser and go to http://gis.
mahoningcountyoh.gov and then select the option for Map Viewer. In the upper left-hand corner
of the screen will be the Property Search functions,
allowing you to search for a parcel of land by Parcel
Number, Owner Name, or Address.
Do a search for parcel ID: 29-042-0-002.00-0
(this is the parcel number for the Boardman Township Park). The map will zoom to the parcel of the
park. In the lower left-hand corner of the screen are
a series of available layers. Place a checkmark in
the box of the most recent available Ortho Photos
(under the Imagery heading). Click on the Refresh
button on the toolbar to see the results of adding
that layer (that is, high-resolution aerial photos of
the park). Select some other layers to examine,
and then refresh the map (by pressing the Refresh
button) to examine that data. Use the tools on the
toolbar (the magnifying glass to zoom in or the hand
to pan around the map) to get a closer look at the
map and the surroundings of the park.
Check your local state or county government’s
Websites to see if an online spatial data viewer (or
GIS) has been set up for your area. It may be part
of your county auditor’s Website or a separate GIS
department for the state or county.
Hands-on Application 5.1
Using GIS Online
CGIS the Canadian
Geographic Information
System — a large land
inventory system used
in Canada and the first
time the name “GIS”
was utilized for this
type of system.