GIS Procedures for MLFD MPB Analysis

The data was processed using ArcInfo.
Due to the large extent of this data set processing time is considerable
ArcMap was used for vusualization and graphical output.

DEM Compilation:

The DEM files were in two separate zones so re-projection was needed before the sheets could be merged:

Code example for zone 9 DEM's Code example for zone 10 DEM's
asciigrid 93l.asc 93l-dem
projectdefine grid 93l-dem
projection utm
zone 9
datum nad83
parameters		 asciigrid 93k.asc 93lk-dem
projectdefine grid 93l-dem
projection utm
zone 10
datum nad83
parameters

project grid 93k-dem 93k-zone9
output
projection utm
zone 9
datum nad83
parameters
end


All DEM sheets were merged (in Grid):

grid
dem-all = merge(93m-dem, 93l-dem, 93e-dem, 93n-zone9, 93k-zone9, 93f-zone9)


Creation of slope and aspect layers:

dem-slp = slope(dem-mpb)
dem-asp = aspect(dem-mpb)

Note: Do not press ENTRE even if "Running ... 100%" appears until the Grid prompt appears on it's own or the file will be corrupt.
(due to the error which resulted from the above the current data set has the asp and slope calculated for the entire DEM)

Creation of DEM-small
In order to reduce display time DEM-all was clipped using the select box function in grid to the area:
Lower Left: 530,000 5,905,000
Upper Right: 740,000 6,160,000

Creation of points coverage DEM:

Limmit to extent of MLFD boundary:

in grid:
dem-bound = selectmask(dem-all, select(bound, 'value > 1'))
dem = gridpoint(dem-bound, elev)
in arc:
latticespot DEM-SLP dem slope
latticespot DEM-asp dem aspect
latticespot pine dem pine
latticespot suscep dem suscep

Data for pine and susceptibility was unloded according to % intensity:
in tables:
sel dem.pat
unload dem.table elev aspect slope pine suscep columnar F8
resel  pine > 0
unload pine.table elev aspect slope pine suscep columnar F8
resel  pine > 25
unload pine-25.table elev aspect slope pine suscep columnar F8
resel  pine > 50
unload pine-50.table elev aspect slope pine suscep columnar F8
resel  pine > 75
unload pine-75.table elev aspect slope pine suscep columnar F8
resel  suscep > 0
unload suscep-0.table elev aspect slope pine suscep columnar F8
resel  suscep > 25
unload suscep-25.table elev aspect slope pine suscep columnar F8
resel  suscep > 50
unload suscep-50.table elev aspect slope pine suscep columnar F8
resel  suscep > 75
unload suscep-75.table elev aspect slope pine suscep columnar F8

In preperation for isolation of data within "slice" coverages the new and mpb data was added to the DEM coverage:

latticespot new95 dem beetle95
latticespot new96 dem beetle96
latticespot new97 dem beetle97
latticespot new98 dem beetle98
latticespot new99 dem beetle99
latticespot new00 dem beetle00
latticespot new01 dem beetle01
latticespot new02 dem beetle02
latticespot new03 dem beetle03

latticespot mpb95 dem mpb95
latticespot mpb96 dem mpb96
latticespot mpb97 dem mpb97
latticespot mpb98 dem mpb98
latticespot mpb99 dem mpb99
latticespot mpb00 dem mpb00
latticespot mpb01 dem mpb01
latticespot mpb02 dem mpb02
latticespot mpb03 dem mpb03

Processing of MPB data:

The original MPB extents were imported into ArcInfo using import.aml.

<>The data sets were limited to areas of new MPB spread for each year using new.aml.
The grid coverages were converted to point coverages and the elevation, aspect, and slope attributes were attached to the beetle data using add_elev.aml.

Statistics In ArcInfo

The general statistics in Table 1 were created from tables in ArcInfo:
tables
sel new95-r2.pat
&r statistics.aml

statistics.aml

The results were cut and paste into a text document and then imported into an Excel spreadsheet.

Exporting Tables

The Point atribut tables were exported from ArcInfo using unload.aml.

The exported data was further analysed using R.  For a full description of graphing procedures see: R Procedures

Analysis of specific areas (circular slices):

15 points were selected for more specific analysis from the DEM points coverage in ArcMap.
these points were exported to a shape file, imported into arc:
shapearc points.shp points2
addxy points2
tables
sel points2.pat
unload ../tables/in.txt points2-ID x-coord y-coord

In R:
source(file="slice.r')  This script calculates the two points of a triangle from the centre given the radius and number of devisions (slices).

In arc:
&r ../aml/slice.aml 
This aml generates a polygon from the points calculated by slice.r, isolates the points in the DEM coverage that fall within the polygon, and creates an output file of the results (slice#-dem.table)

For further Information Contact Vera Lindsay
lindsayv@unbc.ca