Environmental Case Study
GIS in Conservation
GIS is an acronym you may hear with increasing frequency in the coming years. What does it
mean, and why are people talking about it? At its most basic, a geographic information system (GIS) is a
computer mapping system. This means that a GIS includes software that organizes spatial information,
such as addresses, types of vegetation in different places, or the shapes of rivers and lakes, as well as
the information itself--the data. In order for users--you and me--to understand all this spatial data, a GIS
also needs to display or print the spatial information. Often a map on a computer screen is the main
display method. On the computer screen you can zoom in and out to see details or overviews in different
places; you can also add and subtract layers, to show different information about an area. Other times a
printed map, which can be folded, carried around, and used anywhere, is the main product of a GIS.
GISs serve many purposes. Most of the road maps you use today have been created with a GIS
that makes map production and updating relatively easy and efficient. Every year your state's department
of transportation, for example, may need to add new roads to its road maps. Your town's planning office
needs to update zoning maps, and the tax assessor needs to maintain records of land ownership and
land values and land uses. By creating computer maps, the data (new roads or land uses) can be
corrected and reprinted relatively quickly. Without a GIS, maps would need to be updated by hand, using
air photos and cameras. GISs are also used by utility companies. The companies that maintain your
water system and your electric and phone lines may use a GIS to keep track of where the lines go, what
their capacity and usage is, and where repairs are needed. Utility workers checking the lines may have
computers in their trucks, or even hand-held computers, that let them access enormous databases of
spatial information as they work, no matter where they are.
There are many applications of GIS in research and in spatial analysis, too. Suppose you knew
the locations of 500 bald eagle nests, and you wanted to know how many of them were near highways
that might pose risks to fledgeling eagles. Without a GIS you could visit all the sites and measure the
distance from roads to each nest, but it might take a long time to visit that many sites. With a GIS you
could overlay the two data sets and ask the computer to instantly calculate the number of nests within 50
or 100 meters of any road. At the same time you could calculate the proximity of nests to each other or to
other key resources, such as lakes or streams where eagles could find fish. Add in a data file identifying
elevations, and you could find out whether eagles tend to like south-facing slopes, or whether they avoid
high-elevation locations.
An infinite number of questions and applications can be explored with a GIS. The main limitation
is usually time and money. Often high-quality spatial data are time-consuming and costly to gather.
Agencies or companies that produce data--and software--are often happy to sell their products, but
sometimes the price is high. Often available spatial data are too coarse, or have too little precise and
accurate detail, for questions a user wants to ask. The computers needed to run the complicated software
may be expensive, too.
Fortunately, the U.S. government and many states and cities have invested heavily in GIS data,
and since these data are created with taxpayer money, they are often available at low cost or even free-especially if you acquire them from the Internet. To get a sense of some of the geographic data currently
available, look at the USGS's EROS data center web site (http://edc.usgs.gov) or at the Minnesota
Department of Natural Resources "data deli" (http://deli.dnr.state.mn.us). Note that you won't be able to
actually use any of the data unless you have the right GIS software and know how to use it. If you choose
to learn a GIS, though, the opportunities and resources available are only going to grow in the coming
years.
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