Transcript Geographic Information Systems Geography 1050 What is a GIS? A Geographic Information System (GIS) is a system of computer software, hardware and data,

Geographic Information Systems
Geography 1050
What is a GIS?
A Geographic Information System (GIS) is a system
of computer software, hardware and data, and
personnel to help manipulate, analyze and
present information that is tied to a spatial
location.
Spatial location: usually a geographic location
 System: linking software, hardware, and data
 Personnel: a thinking explorer who is key to the
power of a GIS
What is a GIS?
 A method to
visualize,
manipulate,
analyze, and
display spatial
data
 “Smart Maps”
linking a database
to a map
Data for GIS Application
 Digitized and scanned maps
 Databases - table of data
 Field sampling
 Remote sensing and aerial photographs
A database - not easy to interpret
Population density in the US
Visual analysis of data
“Picture is worth a thousand words”
Population density in the US
Different data layers combine
Maps and databases are “Interactive”
GIS User:
 asks
questions
 sorts and
combines
data
 looks for
patterns and
connection
Two ways to display spatial data
Raster - Grid
 “pixels”
 a location and value
 satellite images and aerial
photographs are in this
format
Vector - Linear
 points, lines, and polygons
(shapes)
 feature (house, road, lake,
etc.) and attributes (size,
type, length, etc.)
Some ways Geographic
Information Systems are used:
 Emergency Services - Fire and Police
 Environmental - monitoring and modeling
 Business - site location, delivery systems
 Industry - transportation, communications,
mining, pipelines
 Government - local, provincial, federal,
military
 Education - research, teaching tool,
administration
CASE STUDY- GIS and Aquaculture
Soft-Shell Clam Site Assessment,
Burgeo, NL
 evaluation of the viability of the soft-shell
clam resource
 GIS technology was applied to collected data
to map and analyze:
physical site characteristics and landuse
water quality
the soft-shell clam resource.
CASE STUDY- GIS and Aquaculture
 study area divided in a series of
100 m x 100 m grid cells.
 Field survey data included:
clam biology (length and width and
weight)
hydrographic data (water depth, current
speed and direction, bottom substrate, tidal
data, rainfall),
water quality data (fecal coliform, salinity,
temperature)
land use data (cottage locations).
CASE STUDY- GIS and Aquaculture
Study area, survey grid and water monitoring locations
CASE STUDY- GIS and Aquaculture
Water Quality
 Contamination by fecal coliform a concern becaue
of nearby cottages
 If density exceeds 13.99MPN/100ml harvesting in
the area is not permitted
 During the majority of the sampling period the
densities were at 1.9 MPN/100ml
 Following extended rainfall event the fecal
coliform densities ranged from 17 to 920 MPN/100ml
CASE STUDY- GIS and Aquaculture
Water Quality: Time Series maps of fecal coliform
CASE STUDY- GIS and Aquaculture
Water Quality
 Clams need salinities of at least 5 parts per thousand
(ppt) to survive
 Salinity in study area fell below 5ppt during rainfall
event
 Fecal coliform densities and salinities returned to
normal more quickly in Big Barasway than in Indian Hole
and Little Barasway
 Big Barasway flushes faster and therefore this area
could be seeded with clams from Indian Hole and Little
Barasway
CASE STUDY- GIS and Aquaculture
Soft-Shell Clam Database and
Aquaculture Management
 Clam densities of different size classes for
each grid cell were calculated and mapped
 Recruit class (clams with a length
between 50 and 63.5mm) represents the
market clam population
 A grid cell is economically viable only if the
recruit clam density is $10/m sq.
CASE STUDY- GIS and Aquaculture
Soft-Shell Clam Database
CASE STUDY- GIS and Aquaculture
Aquaculture Management
 Mature clam densities of 161 to 269/m sq.
are acceptable for good growth
 Densities higher than 269/m sq. can impede
growth because of competition for food and
space
 When the density of mature clams exceeds
269/m sq. the area should be culled
CASE STUDY- GIS and Aquaculture
Harvesting Plan
 GIS is able to identify areas of no harvesting,
harvesting only, culling only, and combined
harvesting and culling.
Criteria for harvesting:
 density of recruit clams > 10/m sq.
Criteria for culling:
 density of mature clams > 269/m sq.
CASE STUDY- GIS and Aquaculture
Harvesting Plan