Geography 1050 5 GIS Powerpoint

7/31/2019 Geography 1050 5 GIS Powerpoint

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Geographic Information SystemsGeography 1050


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What is a GIS?

A method tovisualize,

manipulate,

analyze, anddisplay spatial

data

Smart Mapslinking a database

to a map


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Data for GIS Application

Digitized and scanned maps

Databases - table of data Field sampling

Remote sensing and aerial photographs


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A database - not easy to interpret

Population density in the US


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Visual analysis of dataPicture is worth a thousand words

Population density in the US


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Different data layers combine


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Maps and databases are InteractiveGIS User: asks

questions

sorts and

combines

data

looks for

patterns andconnection


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Two ways to display spatial dataRaster- Grid

pixels a location and value

satellite images and aerial

photographs are in thisformat

Vector- Linear

points, lines, and polygons

(shapes)

feature (house, road, lake,

etc.) and attributes (size,

type, length, etc.)


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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.


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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, currentspeed and direction, bottom substrate, tidal

data, rainfall),water quality data (fecal coliform, salinity,

temperature)

land use data (cottage locations).


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Study area, survey grid and water monitoring locations


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Contamination by fecal coliform a concern becaueof 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

Water Quality


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CASE STUDY- GIS and AquacultureWater Quality: Time Series maps of fecal coliform


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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

Water Quality


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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.

Soft-Shell Clam Database and

Aquaculture Management

CASE STUDY GIS d A lt


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CASE STUDY- GIS and AquacultureSoft-Shell Clam Database


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Aquaculture Management

Mature clam densities of 161 to 269/m sq.

are acceptable for good growth

Densities higher than 269/m sq. can impedegrowth because of competition for food and

space

When the density of mature clams exceeds269/m sq. the area should be culled


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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.


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Harvesting Plan

Documents

Geography 1050 5 GIS Powerpoint