GIS Applications in the
Environment & Geomorphology
GIS
• Geographic Information Systems (or
Sciences)
– Systems implies a software program or suite of
programs
– Sciences implies the theoretical framework,
programming, processes and platform
What is GIS?
• An tool that is used to analyze any data or
set of data that is spatial in its distribution
GIS
• Many disciplines contribute to GIS
– Geography, cartography, geology, computer
programming...
• Disciplines who use GIS in their work
include:
Red areas of southern Florida are
susceptible to a five-meter rise of sea
level, based on elevation. Yellow
denotes urban areas.
GIS is used to…
• Facilitate communication between
different entities
• Solve problems
• Make decisions
• Understand past and present situations
• Anticipate future scenarios
– Geography, geology, criminal justice,
sociology, meteorology, political science,
archeology…
Using GIS in Geology
• Geomorphology: mass movements (slope
stability, old deposits), channel erosion,
barrier island movement
• Environment: soil erosion, land use/land
cover change, flood zones
– Inventories: landslide location, new construction,
septic tank location, flora and fauna distribution,
flooding history, regional geology, groundwater
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How does GIS work?
• As a tool, researchers look at how multiple
variables intersect with each other
How does GIS work?
• Can use spatial data, nonspatial data, and
images
– Analyzing HOW the variables interact is done
in GIS
• Analyzing often done through a series of
maps
– Advantage of GIS is that is can be instantly
updated
GIS and Remote Sensing
• Two tools work together very well.
• Remote sensing is acquisition of
information of an object or phenomenon,
with a device not in actual contact with the
object
China’s
Quake Lake
– Photographs or satellite images are the most
common
– Collect information without being there
Formosat image © 2008 Dr. Cheng-Chien Liu, National
Cheng-Kung University and Dr. An-Ming Wu, National
Space Organization, Taiwan.
0.5 meter resolution = 1.6 feet
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Basic analysis tools
• Overlay – stacking data on top of each
other
• Buffers – drawing a bubble around a
variable
Erosion potential model-Colby College
Overlays
• The most fundamental analysis tool in GIS
• Display 2 or more variables spatially to
understand and interpret their relationship
– Example: Topography and vegetation; land
use and landslides; hurricane storm surge
and residences
Erosion impact map-Colby College
Road
type
LandSeries
Soil
use
Erosion impact map-Colby College
Overlay example: landslides
• Mapped Pleistocene landslides using
aerial photographs and an image that
shows the elevation of the area
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Digital Elevation
Models
Landslides
Landslides: Lewis Overthrust Fault
• Aspect – direction of a slope
• Fault in northwestern Montana where
older deposits are over younger deposits
Landslides, Glacier National Park
0
Buffering
270
90
180
Study area, Glacier National Park
• Analytical tool that is used to isolate a
certain region based on a particular
feature (e.g. river, habitat, type of land
use)
N
W
E
– Uses buffers set at a distance determined by
the analysts
– Example: all the restaurants within 5 miles of
campus
– Reduces the amount of data to analyze
S
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Databases
Buffering zones around
areas of hazardous
contamination
Source water protection areas for the
Las Vegas Valley watershed based on
the extent of dry weather flows. Zone A
is a 500 foot buffer and Zone B is a
3000 foot buffer from Zone A.
• GIS uses spatial databases (like the
distribution of oil rigs in the Gulf) and
nonspatial databases (a list of the oil rigs
in the Gulf – their owner, age, production)
• Databases can be updated and ongoing
problems or issues can be constantly
observed and re-analyzed
http://proceedings.esri.com/library/userconf/proc02/pap0
439/p0439.htm
Earthquake damage
Landslide inventory
Kobe Earthquake, 1995
Yamazaki, F. 2001. Applications of remote sensing and GIS for damage assessment. Structural Safety and Reliability, Corotis et al. (eds)
Wildfires
Seismic risk
maps
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GIS, Geology, and Terrorism
• Understanding the basic geology,
topography, and important landforms of an
area is essential in the use of GIS in any
project
Professional Geographer, Volume 57, Number 4, November 2005
Professional Geographer, Volume 55, Number 2, November 2003
Professional Geographer, Volume 55, Number 2, November 2003
Professional Geographer, Volume 55, Number 2, November 2003
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Mapping floods
• Using an image, a land use map, stream data,
road network, precipitation totals, and soil data,
the timing of flood inundation can be predicted
Flood mapping in urban areas
• Floods: Influenced by bedrock,
topography, soil, and typical rainfall events
• Flash floods: rainfall in a short amount of
time
– Typical in western US: little soil
– Flash floods – need maps showing most
recent flooding events
– Will flood in same place as overland floods
but with greater unpredictability
Overland flow
Flood zone maps
• Flood zone maps created by FEMA
– 100-year & 500-year maps
– Uses previous flood history to create maps
– Maps should be revised with new construction
and new flood history
– Overlay flood history, roads, and stream
network
– Powerful maps – those people in 100-year
flood zone required to have flood insurance
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In summary
• Knowledge of land use and
topography are necessary in
GIS applications
• GIS can uses multiple kinds
of spatial data, notably field
data and existing maps
• Combination of remote
sensing with GIS makes
them a powerful tool
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