Refuge Notebook
Article
Dated
October 30, 2003
Map making arrives in the 21st century
by Andy DeVolder
Two
weeks ago when I was carving pumpkins with a group of friends, we were using those
cool new patterns to trace our designs onto the pumpkins. The designs were on
flat pieces of paper that we taped to the pumpkin, then we pricked our pattern
into the skin of the pumpkin and cut out the design using handy little saws that
came with the patterns. One thing I wondered aloud was how well the flat pattern
fit on a curved pumpkin? There was considerable distortion in the pattern when
it was wrapped around the curved surface, however we made the best of it and all
of the jack-o-lanterns came out great, even Martha Stewart would have been proud.
Transferring a flat design to a rounded pumpkin is the same sort of problem that
map makers have been contending with for hundreds of years.
As the new
fish and wildlife biologist here at the Kenai National Wildlife Refuge, my primary
responsibilities are in managing the geographic information system, or GIS, and
the loads of geographic data associated with it. Creating and thinking about maps
is one of the things that I do on a daily basis. As early as AD 140, the Greek
thinker Ptolemy produced a map of the earth that was spherical, but it was not
until the voyage of the Victoria (1519-1522) when Ferdinand Magellan circumnavigated
the world that we had conclusive evidence that the earth was not flat but round.
From that first map, up to today, the issue of how to draw a round earth as flat
image with minimal distortion has been a nagging map making dilemma. Over the
years, many different ways to represent the surface of the earth have been developed.
Each way is called a map projection and the three used most in Alaska are the
Albers Equal Area Conic, State Plane and the Universal Transmercator (UTM) Projection.
Each projection has benefits over others, but unless you are making maps those
are unimportant details.
As I mentioned GIS is more than making maps, is
can be used to answer resource based questions or create models of real world
processes. For instance, if you wanted to know how many lakes with a specific
fish are within a certain distance from a good trail or road, we could plug that
question (also called a query) into the GIS and create a map of lakes that meet
those criteria. Since it is nearly impossible (and not practical) to inventory
every acre of the 2 million the refuge manages, GIS can be used to produce models
of the entire refuge.
You may recall the Kenai Lake fire that began in
late June of 2001. Since firefighter and public safety is the primary concern
of the Forest Service they requested a GIS analyst to help them map the fire.
I responded to the call and arrived at the Kenai Lake Work Center in Crown Point
The first thing that fire managers wanted to know was the location of homes and
other structures to formulate an evacuation plan if needed. I started by using
the Kenai Borough parcel database information to discriminate between residential
structures and vacant lots. I printed a series of detailed maps using high resolution
satellite imagery as a base for firefighters to use in the event of rapid evacuation.
Thankfully no evacuation was needed, but the maps provided the base for their
effort to inform home owners of the potential for an evacuation. Throughout the
week that I was on scene, I made other maps showing the progress of the fire,
location of safety zones, drop points, fire crews, and public information maps.
As you can imagine, having accurate and current maps provided for a high level
of safety for firefighters and also served to inform the public of fire suppression
progress and safety plans.
We are all very familiar with the spruce bark
beetle infestation that has killed nearly every mature white spruce on the Kenai
Peninsula. We are also all to familiar with the dry summers we have been having,
burn bans, and increased wildfire risk. Do you know where the greatest wildfire
risk on the Kenai Peninsula is? It could be in your back yard (I though it used
to be in mine before we got the trees removed), however many factors contribute
to wildfire risk including fuels, ignition sources and topography. Using GIS we
can combine these factors into a model that will show where the range of wildfire
risk for the Kenai Peninsula. As you might expect, the areas around towns and
homes (where ignition sources are) that have spruce bark beetle-killed trees show
the highest wildfire risk, and areas in the hinterlands of the refuge even with
spruce bark beetle-killed trees show a lower risk (very few ignition sources).
Of course models do not totally represent the real world, rather it is our best
estimation based on the available information.
Technology has evolved by
leaps and bounds in the short time that I have been professionally doing GIS work.
Computers have become faster and storage capacity has also increased dramatically,
both of which contribute to faster modeling and more complex map production. One
of our newest tools is a combination handheld GPS/GIS field computer. This little
unit weighs about three pounds, has a nice GPS unit with 5 meter accuracy and
a full color screen to display digital topographic maps, aerial imagery. We can
load information about land ownership, vegetation types, and location of roads
on to this unit too. When we get out to do field work, we can now record our observations
or surveys directly to a digital file, or display our location in real time on
digital topographic maps as we walk through the woods. We can also have the GPS
record where we walk, tracing a line (such as along a stream) or capturing vary
accurately located points perhaps to identify an eagle nest. Using GPS to locate
features on the ground such as signs, outhouses, campgrounds, and access points
will help us make better more accurate maps, which in the long run helps you,
the refuge user. So GIS and GPS technology is not just for biological resources
it is for anything that has a spatial location…which I suppose is everything!
Now that’s job security and many opportunities to out from behind my computer
and get in the field.
Next time you look at a map, think about what went
into making it accurate and reliable and the long history of map making. Be safe
when you go out tonight and when you see all of those carved pumpkins give some
thought to Ptolemy, Magellan (from who a company and a line of GPS receivers is
named) and modern computer based GIS technology.
Andy DeVolder has worked
for the Spruce Bark Beetle Mitigation Program in Soldotna and the US Forest Service
in Seward and now is the Biologist/ GIS Data Manager for the Kenai National Wildlife
Refuge. Previous Refuge Notebook articles can be viewed on the Refuge website
at http://kenai.fws.gov.
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