Page 43 - 4. Pre-Course Reading-Training on Forestry Audit 2019

Appendix 2: Using GIS and GPS in Forests Audits

A GPS receiver calculates its position by carefully timing the signals • Spatial data on the administrative boundary of a district.
sent by the constellation of GPS satellites high above the Earth. • Spatial data regarding forest zone.
Each satellite continually transmits messages containing the time
the message was sent, a precise orbit for the satellite sending the • Spatial data regarding the LFC boundary.
message, and the general system health and rough orbits of all
GPS satellites. These signals travel at the speed of light through
outer space, and slightly slower through the atmosphere. Data processing:
• If hotspot data is still in excel, it needs to be firstly trans-
formed to spatial data. Use the add XY tool provided in
The receiver uses the arrival time of each message to measure GIS. This tool will transform X and Y data (hotspot coordi-
the distance to each satellite thereby establishing that the GPS nates) in excel into map coordinates for use in further analysis.
receiver is approximately on the surfaces of spheres centered at
each satellite. The GPS receiver also uses, when appropriate, • Then, intersect the hotspot spatial data with district
the knowledge that the GPS receiver is on (if vehicle altitude is administrative spatial data, forest zone spatial data, and
known) or near the surface of a sphere centered at the earth LFC spatial data. This intersection will provide new spatial
center. This information is then used to estimate the position data showing in what district the hotspot occurs, in what
of the GPS receiver as the intersection of sphere surfaces. The forest zone, and in what company.
resulting coordinates are converted to a more convenient form • Classify the hotspots based on the number of spots in each
for the user such as latitude and longitude, or location on a map, district. Use the summarize tool in GIS software to give out- 43
then displayed.
put in database format (.dbf).
For more information see www.gps.gov
• This database can them be presented as a table of hot-
spots for each district and each forest area. The example
of the result is shown in the following three tables.
HOW TO USE GIS AND GPS
IN FORESTRY AUDITS

The main phases in forestry audits are planning, execution, and
reporting. GIS could be used in planning whereas GPS could Data Requirement for Analysis
be used in execution phase as a supporting tool.

During planning, GIS could be used to select samples to be
audited, and help us to select from various objects that are
relevant to the audit objective/s. For example, we could use
GIS to determine which LFC has the highest hotspot which is
a section of forest or woods where fires frequently occurred
on the forest area that has highest level of deforestation (along
with its precise location).
During the execution phase, GPS can provide evidence on the
results of planning from using GIS analysis, and it enables us
to locate the precise point where there is a problem.

SOME EXAMPLES

How to utilize GIS in forestry audits depends on the research
question we ask. The following examples show how GIS and
GPS can be used to answer a range of research questions.

1. RESEARCH QUESTION: Have fire prevention activities
performed by UPT PHKA, local forest agency, and LFC
been conducted in accordance with the regulations and
were effective in reducing fire incidence?

Minimum data requirement:
• Spatial hotspot data containing the point where the hot-
spot occurs (time series data).