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Forest Practices > Forest Health > Forest Investment Account
Forest
Investment Account
ELIGIBLE ACTIVITIES
– Aerial Detection for Bark Beetle Management
Objectives:
Annual detailed mapping of recently
faded (red) dead trees is a cornerstone for all operational treatments
for bark beetle suppression activities. Over the last 20 years,
detailed surveys have been conducted using various techniques which
have become increasingly more accurate with the advent of Global
Positioning Satellite (GPS) based navigation and digital
photography. All methods serve one purpose – to provide the
locations of red tree “infestation centres” in a timely
manner to initiate a ground survey to locate green (currently)
attacked trees. The ultimate goal for this level of
detection is to treat 80 to 100% of the brood trees prior to the next
beetle flight to meet the suppression BMU objectives. Although
all operational aerial detection methods only record red attack,
ground surveys usually locate most of the current attack in the
immediate vicinity (~100 m) of red attack in sub-outbreak
populations.
Acceptable detection methods must be able
to:
- Provide an acceptable estimate of
the numbers of red tree crowns and provide sufficient positional
accuracy to initiate a ground survey for green (current) attacked
trees;
- Deliver maps to initiate ground
detection ideally by October 1st each year following the aerial
survey. The survey can begin in early July of that year and
continue until late September; and,
- Summarize the data into a format
that can be readily managed with existing information systems in
an operationally acceptable time frame.
Description of Eligible Activities
READ THE ELIGIBILITY
CRITERIA FOR BARK BEETLE MANAGEMENT ACTIVITIES FIRST
The following are a short descriptions
of acceptable methods.
- Sketch Mapping and
Helicopter-borne GPS Surveys (Heli GPS)
These methods are most suitable when
there are only a small number of infestations located in widely
spaced locations. Sketch mapping (i.e., using a helicopter or
fixed wing and hand drawing locations on paper maps) is the least
accurate but lowest cost method and uses methods similar to the aerial
overview survey but is conducted at lower altitude or higher
intensity. In some cases where infestations are at such low
levels or treatments are not being proposed, the aerial overview
survey maps may provide sufficient information.
Heli-GPS (i.e., flying over an
infestation centre and recording the GPS waypoint plus some minimal
attribute data, usually a pest code and severity) is more accurate
but can be more expensive than sketch mapping. It has the
advantage of rapid data transfer directly into a GIS or database vs.
sketch mapping which would require digitizing the data into a
GIS. Compared to other aerial detection methods, if properly
conducted, both the errors of omission (of red tree infestation
centres, not necessarily tree counts) and commission (it is the
most accurate method for correctly identifying the damaging agent)
are very low.
These surveys can be be quickly
initiated whenever suitable weather conditions occur and offer short
turn-around times for data processing.
STANDARDS
- Photography (Conventional and
Digital)
Photography has several advantages
and some significant disadvantages compared to non-photographic
surveys. Photography's greatest advantage is that the images
provide the most accurate depiction of the location and distribution
of the individual red tree crowns. Secondly, the images have
multiple uses that greatly facilitate the operational planning of
follow up ground detectiFebruary 13, 2006February 13, 2006February 13, 2006nbsp;
Disadvantages include potentially
higher unit costs particularly if the infestation centres are widely
dispersed. Costs are highly variable and are dependent on the
contract specifications, project size, contractor
availability, weather and other factors. Most
importantly, some photography projects may have longer delivery
times from image capture to map production compared to
non-photography-based surveys which may jeopardize the timely
implementation of treatments. Another disadvantage is its
lower accuracy of identifying the correct pest damage agent compared
to heli-GPS where the observer can inspect the tree bole for other
symptoms. Identification error can be reduced if the photo
data is cross-referenced to forest cover types or viewed in stereo which will narrow
down the range of potential pests.
Eligibility for ALL aerial
photography (conventional and digital) projects funded by FIA will
be determined using the Ministry of Sustainable Resource Management's
Base
Mapping Geomatic Services (BMGS) Branch Standard Operating Procedure
(SOP) for mapping
projects. The detailed Standard Operating Procedure documentation
is located http://srmwww.gov.bc.ca/bmgs/sop/index.html and submission forms. (See Rationale). No
additional aerial photography will be approved in areas that are already
included in the provincial beetle photography and mapping
contract.
GENERAL STANDARDS FOR PHOTOGRAPHY
No remote sensing (other than
those listed above) methods are eligible at this time.
Note:
Satellite borne detection (LANDSAT 5 and 7) of single red trees and/or small
clusters of red trees is still at the research stage and, at 30 m
pixel resolution, is not
accurate enough to be considered an eligible operational activity for
detection of infestations for single tree treatment. Other
remote sensing methods (i.e., SPOT 5, Quickbird, etc.) have not been
shown to be operationally feasible at this time due to cost, limits of
resolution, delivery scheduling of map products, and higher than
acceptable errors of omission and commission. Licensees
may continue to explore the use of this method but will have to fund
the work on their own, or obtain FIA funding under a bona fide operational trial, or
as an approved research project under FII (or through the Federal MPB
initiative). The
same conditions apply for proposals for green attack detection using remote sensing. To date, no operationally demonstrated
methods are available. Research and operational trials must
follow the protocols outlined in MOF
Standards for Research Trials of Mountain Pine Beetle Detection Using
Remote Sensing Projects (Word
97, 52 k, posted April 1, 2003)
STANDARDS
General
Detailed Aerial Survey Standards
-
Helicopter/GPS (heli-GPS) fixed surveys are
the operational benchmark for accuracy, delivery
time and cost for detailed aerial surveys at this time.
Please note that not all infestations
warrant the use of heli-GPS surveys or other high resolution
detection methods and less costly and
less accurate surveys may satisfactorily serve the detection needs for
a given situation (e.g., sketch mapping with fixed wing aircraft
augmented with 35 mm colour photos). Consult the MOF forest district or the
regional entomologist for more information and advice on selecting the
most appropriate survey method.
This standard provides GPS co-ordinates for detected
centres of red attack with a horizontal accuracy of approximately
20m (see GPS standards below) . Errors of commission (i.e., identifying a centre of red attack
where there is none) are extremely low (<5%); errors of omission (identifying a
non-infested site when it is infested) have not been measured, but are
dependent on the effort expended to survey a particular area.
If complete coverage is achieved, this error rate is probably less
than 5% (i.e., more than 95% of the infested sites are located). In terms of
image resolution, the level of accuracy consistent with
helicopter/GPS surveys is obtained with images produced at 1m pixel
(50 cm being ideal) resolution.
In general, the aerial detection method must be able
to identify both the number and location of individual red tree
crowns and the species of tree killed.
The final product of this mapping exercise shall be
a map (and GIS files) showing:
-
The location(s) of red attacked trees, pest codes,
and tree counts (if spots - +/- 10%) or severity (if polygons +/-
5%) with GPS
coordinates adequate to allow ground crews to find the centre of
an infestation site with
+/- 25 m accuracy
Infestations will be depicted as either points
(spots) with tree counts or polygons with infestation severity (in
10% increments) (see digital data standards below)
-
The perimeter of area covered by the survey
-
Photography can achieve this mapping standard with
aerial triangulation but without ortho-rectification.
The estimated unit cost for the standard detailed
survey (helicopter/GPS) is $0.15/ha (product = map delivery). Other survey methods MAY be
used for this survey if the information provided is AT LEAST as
detailed as the standard and AT NO GREATER COST and the final map
product is delivered within the desired operational time frame.
-
Methods providing greater accuracy than the minimum
standard for detailed surveys but having costs greater than the
optimum unit costs may be considered if they provide significant
additional value to the Crown.
Detailed Aerial Survey
Data Standard
Deliverables
-
Digital copies of the
detailed aerial survey data in ArcView Shape files or ArcInfo format
to the specifications described above must be provided by the end of
the fiscal year to Forest Practices Branch. The respective
district offices must receive the data as soon as it becomes
available to assist in monitoring and communication to non-TSA
parties (i.e., Parks, woodlots, private land holders).
GPS Standards
-
Aerial Surveys - +/-
20 m horizontal accuracy (see note above). Based
on the information in the document BC Standards and
Specifications and Guidelines for Resource Surveys Using Global
Positioning System (GPS) Technology Release 3.0 - Section E -
Autonomous GPS Guidelines (BMGS
GPS Resource Specifications Release 3.0), positional
accuracy for bark beetle detection usually falls under the
category of "non-critical" since the allowable
horizontal errors for collecting point data can be greater than 10
m. Thus, at minimum, locations recorded by hand-held
autonomous GPS receivers (i.e., recreational use receivers)
provide an acceptable level of accuracy when under clear tracking
conditions. As noted in the
guidelines above, some caution in their use is required to
minimize error. In most cases, the objective of the survey
is to obtain the location of the "infestation centre"
within 25 m rather than obtain the precise location of each
infested tree within the infestation centre. For improved
accuracy, surveys should use differential GPS or high-end
autonomous GPS receivers whenever possible.
General
Standards For Photography
- Conventional Vertical Photography
(film) - must follow BMGS standard (see above)
and not be included in the Provincial bark beetle photography
contract.
- Vertical digital photography -
each project will be reviewed as part of the BMGS
SOP. At this time, no digital camera specifications
have been approved by the Corporate Base Mapping Advisory
Committee (CBMAC). These specifications are being
developed by a CBMAC technical working committee but will not
be available by summer, 2004.
- Oblique photography used to
supplement heli-gps survey information is not considered a
potential base mapping product and proposals do not require
review by BMGS.
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Last updated on
March 13, 2007
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