Canada Maps Deforestation
By Barbara Shields, Esri Writer
The United Nations, national governments,
frozen organic soil releases relatively little
to monitor deforestation and calculate the car-
nongovernmental organizations (NGOs), and
CO2.
bon storage and changes, which are essential
many others are striving to improve the
Canada grows 10 percent of the world’s for-
for Canadian national assessments.
planet’s health by reducing greenhouse gas
est cover and 30 percent of the world’s boreal
The process was begun by developing stan-
emissions. Forests play a major role in purify-
forest. There are approximately 347.7 million
dards for consistency that can be used for data
ing the air because of their ability to absorb
hectares of forests in Canada. During the
review across the country as well as meeting the
and store greenhouse gases such as carbon
past 35–40 years, Canada has converted
measurement standards of the United Nations
dioxide. Scientists use image processing tools
3.3 million hectares of its forestland to other
Framework Convention on Climate Change
and ArcGIS to exploit rich information con-
uses, which is about 1 percent of its total for-
(UNFCCC), which is the international environ-
tent from satellite and aerial imagery, field
ested area (figure 1).
mental treaty to which Canada has agreed.
measurements, and climate simulation models
Canada is a signatory of Kyoto Protocol
Canada’s forest carbon reporting system is
to calculate and report on the forest’s carbon
and is obligated to report greenhouse gas
called the National Forest Carbon Monitoring,
sequestration sources and changes.
sources and sinks associated with affor-
Accounting and Reporting system. The
According to the Woods Hole Research
estation and deforestation. To do so, it has
Canadian Forest Service uses the Carbon
Center, the world’s largest terrestrial carbon
implemented a national forest sector car-
Budget Model of the Canadian Forest Sector
reservoir is its boreal biome. Boreal forests
bon accounting system that brings together
(CBM-CFS3) within this system to estimate
cover 14.5 percent of earth’s land surface
data from multiple resources including a
emissions and removals associated with land
and contain 30 percent of its carbon. In bo-
national forest inventory, growth and yield
conversions to and from Canada’s forests.
real regions, such as Canada, extremely low
data from sample plots, statistics on change
Researchers use the Carbon Budget Model to
temperatures also promote the formation of
agents, and land-use change calculated from
assess carbon stock change over time. This
permafrost. The cold temperatures within
remote-sensing data. The accounting method
model simulates forest carbon stocks in above-
permafrost reduce decomposition rates. This
integrates image processing and GIS analysis
ground and belowground biomass, litter, dead-
Figure 1. Canadian Forest Service maps deforestation to show where forests have been converted to other types of land use over time. Orange represents where
sampling has occurred.
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Spatial sampling methods also make accounting feasible. A grid is laid over the
imagery, and cells within the grid are sampled
to assess land-use change (figure 3). Sampling
density varies depending on the expected rate
of deforestation, and 6 to 12 percent of an area
inspected may be sampled. The area for each
deforestation event is rated against all the cells
inspected and detailed in each deforestation
category class.
Areas of change in the imagery are detected
and flagged. ArcGIS shows where change has
occurred, highlights potential areas of forest
clearing, and compares imagery from different years. Then forestry specialists take over
Figure 2. Carbon emissions and removals are calculated using remote-sensing data and GIS processing. This
analysis is included in the National Inventory Report.
the interpretive analysis (figure 4). Events are
classified in accordance with the Deforestation
Interpretation Guide (DIG) provided by
wood, and organic carbon soil. The results of
of the electromagnetic spectrum and store it
Natural Resources Canada. This way, every-
analyses are included in Canada’s annual green-
in an archive. This is an enormous amount of
one uses the same standard definition, which
house gas inventory and National Inventory
data to consider. To meet UNFCCC account-
supports consistent interpretation across the
Report (NIR). Estimates date back to 1990.
ing requirements, CFS tries to sample the
country. To verify Landsat imagery interpre-
Natural
Canada—Canadian
same areas repeatedly to examine change over
tation, experts use aerial photos, forest inven-
Forest Service (CFS) tracks what is happen-
Resources
time. The time periods used are 1975–1990,
tory, road networks, gravel pit licenses, and
ing to the country’s forestlands—specifically,
1990–2000, and 2000–2008. Landsat mul-
oil and gas facility data. The imagery dataset
where and when deforestation has occurred
tispectral scanner (MSS) was used for 1975,
contains more than 70,000 photos for land-use
and to what the forest has been transformed
and Landsat Thematic Mapper and Enhanced
verification.
(figure 1). CFS monitors causes of land-use
Thematic Mapper Plus (ETM+) were used for
The deforestation monitoring group is
change such as from urban development.
subsequent time periods.
working with Canada’s National Forestry
The measurement of forest change provides
Information System (NFIS),
factors applied to carbon calculation models
which makes forest data
required by UNFCCC (figure 2). This data
available to the public. The
also provides regulators and policy makers
public is invited to view
with a basis for developing sustainable forest
and
plans.
knowledge on deforestation
The measurement process begins from
events used in the calcula-
above with Landsat imagery and aerial pho-
tion of Canada’s deforesta-
tography. Satellite imagery provides a means
tion rates. The site can be
for spatially measuring land-use change.
accessed at nfis.org/. Select
Temporal imagery of land-use comparisons
Language,
reveals where the most change has occurred.
Input Deforestation”. Create
Landsat is an efficient remote-sensing data
a new user and log in.
source for forest analysis. Landsat multispec-
Esri and PCI Geomatics
tral earth-orbiting satellites, developed by
have now fully integrated
NASA, scan Canada’s vast forests using sen-
their GIS and imagery ca-
sors to digitally record reflected and emitted
energy from the earth in various wavelengths
esri.com/forestry
Figure 3. Data within these grid cell samples is compared over time.
ArcGIS highlights areas of land change.
provide
their
then
local
“Public
pabilities to help GIS users
continued on page 10
Forestry GIS Journal 9
continued from page 9
Canada Maps Deforestation
make efficient use of their growing volumes of
system for managing, disseminating, visual-
to the project by mapping deforestation, sup-
imagery datasets. To process its imagery, CFS
izing, and analyzing spatial data. The valuable
plying imagery and geospatial data, doing
uses Geomatica remote-sensing software, pro-
information provides the scientific basis for
ground truthing, and giving expert advice. In
vided by PCI Geomatics, and ArcGIS. PFC
Canada’s forest carbon accounting system.
addition, various consulting firms throughout
also uses Geomatica’s image processing tools
CFS’s carbon accounting team converts the
the country have been qualified to provide
to orthorectify and enhance Landsat imagery
deforestation area information for inclusion
mapping services based on the standard DIG
and build image stacks for change detection.
in the National Forest Carbon Budget Model.
methodologies.
ArcGIS is used for data management and
Environment Canada then assembles data
Special thanks to CFS’s Andrew Dyk
analysis that support the understanding of for-
on various greenhouse gas emissions related
([email protected]),
est events. CFS uses a Live Links tool link-
to forestry, agriculture, energy, and industry
Leckie, and Sally Tinis for providing the in-
ing the cursor position on both ArcGIS and
across Canada in its national greenhouse gas
formation for this article.
Geomatica displays, thereby allowing the sys-
inventory calculations. It uses this informa-
Learn more about Esri’s GIS solutions for
tems to be used simultaneously.
tion as it develops and publishes its National
climate change at esri.com/climatechange
The convergence of GIS and imagery makes
Inventory Report to meet the reporting re-
and forest management at esri.com/forest
it possible for CFS to integrate imagery as
quirements of UNFCCC.
and PCI Geomatics imagery technologies at
core to GIS to meet its wide range of imagery
Canada’s
Carbon
pcigeomatics.com. Read about the CFS carbon
requirements and maximize the value of its
Monitoring, Accounting and Reporting sys-
accounting team at carbon.cfs.nrcan.gc.ca/
spatial data.
tem has engaged provincial and territorial
index_e.html.
Resource managers use this integrated
governments and private industry. Provincial
platform for imagery solutions as a complete
and territorial governments have contributed
National
Forest
Donald
G.
Figure 4.
This example shows the mapping
of deforestation from the
construction of the University of
Northern British Columbia (UNBC)
near Prince George, BC.
10 Forestry GIS Journal
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