Date: December 22, 1992
To: Recipient of Data for Vegetation Map of Brazil
From: Dr. Norman B. Bliss Tel: (605) 594-6034
Principal Scientist
Land Sciences Section Fax: (605) 594-6589
EROS Data Center email: bliss@dg1.cr.usgs.gov
Sioux Falls, South Dakota 57198
Subject: Documentation of Data for Vegetation Map of Brazil
1. This file is distributed with the data as BRVEG11D.README.
2. The MAPA DE VEGETACAO DO BRASIL was digitized at the U.S. Geological
Survey's EROS Data Center, Sioux Falls, South Dakota. It was
produced by:
Ministerio da Agricultura
Instituto Brasileiro de Desenvolvimento Florestal
Secretaria de Planejamento e Coordenacao
da Presidencia da Republica
Fundacao Instituto Brasileiro de Geografia
e Estatistica - IBGE
1988
Original scale 1:5,000,000
Original projection: Polyconic
3. The original map contains both vegetation codes and overprints. The
Vegetation codes were digitized using the same one- or two-letter
codes that are used on the legend of the published map. The overprint
codes were sequentially assigned in the order that they were
encountered in the map legend:
OP Overprint code
-- --------------
1 CAMPOS
2 CAMPANHA GAUCHA
3 CAMPOS DE RORAIMA
4 CAMP. GAUCHA
5 FLORESTA ATLANTICA
6 ATIVIDADES AGRICOLAS
Where there was no overprinting, an overprint code of zero (0) was used.
In the ANTROPICA column, the legend defines the codes S, E, T, D,
A, M, F, C, and P to indicate human influences, and the map is shaded
with fine dots. These are not considered overprints because the
vegetation codes uniquely identify these conditions, and the overprint
code is zero (0). In some cases, such as where the D code is combined
with FLORESTA ATLANTICA, then a non-zero overprint code is used.
4. Some of the polygons on the original map were not labeled. The
code NOLAB was entered for the vegetation code. This is discussed
in more detail below.
5. Water was coded as WATER for the vegetation code. The polygons for
the rivers and the Lagoa dos Patos were arbitrarily closed
at the contact with the Atlantic Ocean. The polygons for the
Amazon river were arbitrarily split so that the polygon shading
in Arcplot would work properly. If these arbitrary lines are
a problem in Arcplot, then the Arc BUILD command could be used to create
an Arc Attribute Table (AAT), the arbitrary arcs could be labeled,
and the RESELECT command in Arcplot could be used to suppress plotting
the arcs.
6. Following digitizing, the map was reprojected into Geographic
(latitude-longitude) coordinates. Since then, the following
updates have been made:
a. Plots were made to compare the data with the original map.
Some polygons were corrected, using the VEG2 and OP2 items.
Thus, the items VEG2 and OP2 should be used if fidelity to the
original map is a primary concern. (December 1991)
b. The polygons that were digitized as having no label (NOLAB) were
identified, and Norman Bliss made a "best guess" as to the
probable vegetation type of these data. These revisions were
coded in VEG3 and OP3. Use of these codes is optional, or the
user may wish to make his or her own interpretation based on the
original map or other data sources. There is considerable
confusion on the original map in the area of 49.5 degrees West,
7.5 degrees South. (December 1991)
c. Seven polygons with codes D or Dm were identified by Liane
Guild (NASA Ames) that should have overprint code of 5 (indicating
Atlantic forest rather than Amazon forest). Five of these were
correctly shown on the map, and the OP2 item was corrected to
reflect this. For two polygons (BRVEGGEO11-ID 1808, 1870) it appears
that the printed map is missing the overprints. All seven polygons
were corrected by calculating OP4 = 5. VEG4 and OP4 now reflect
the best estimate of the vegetation and overprint codes. The VEG3
and OP3 items were deleted. (June 18, 1992)
7. The data are distributed as an Arc/Info interchange file. Arc/Info is
is a proprietary geographic information system software package
developed by the Environmental Systems Research Institute, Inc.,
Redlands, California.
8. The interchange file was created using the Arc/Info EXPORT command:
EXPORT COVER BRVEG11D BRVEG11D
9. The data can be read using the Arc/Info command:
IMPORT COVER BRVEG11D BRVEG11D
10. This will result in a coverage BRVEG11D. This name connotes:
BR BRazil
VEG VEGetation
11 Version 11 of the file
D Distribution format
A distribution format for the data has been created that removes the
additional items that were added at the EROS Data Center for our
own processing, analysis, and plotting. Those items could confuse
a user, and perhaps lead to erroneous results.
11. The follwing files are present in the coverage, with the size in
bytes indicated (the size of the log file may differ):
arc 1409948
arx 48644
bnd 16
cnt 51480
cnx 17228
lab 68580
log 1410
pal 211104
pat 59948
pax 17228
prj 567
tic 72
tol 36
12. The following files are present in the INFO directory. The
INFO internal names may be different following the IMPORT.
ENTER COMMAND >DIR
TYPE NAME INTERNAL NAME NO. RECS LENGTH EXTERNL
DF BRVEG11D.TIC ARC000DAT 6 12 XX
DF BRVEG11D.BND ARC001DAT 1 16 XX
DF BRVEG11D.PAT ARC002DAT 2141 28 XX
DF BRVEG11D.NAME ARC003DAT 94 186
13. The Arc/Info DESCRIBE command gives:
Arc: describe brveg11d
Description of SINGLE precision coverage brveg11d
ARCS POLYGONS
Arcs = 6068 Polygons = 2141
Segments = 145891 Polygon Topology is present.
0 bytes of Arc Attribute Data 28 bytes of Polygon Attribute Data
NODES POINTS
Nodes = 4367 Label Points = 2140
0 bytes of Node Attribute Data
TOLERANCES SECONDARY FEATURES
Fuzzy = 0.000 V Tics = 6
Dangle = 0.010 V Links = 0
COVERAGE BOUNDARY
Xmin = -73.979 Ymin = -33.779
Xmax = -34.811 Ymax = 5.230
STATUS
The coverage has not been Edited since the last BUILD or CLEAN.
COORDINATE SYSTEM DESCRIPTION
Projection GEOGRAPHIC
Units DD Spheroid CLARKE1866
Parameters:
14. The items in BRVEG11D.PAT are:
ENTER COMMAND >SEL BRVEG11D.PAT
2141 RECORD(S) SELECTED
ENTER COMMAND >ITEMS
DATAFILE NAME: BRVEG11D.PAT 12/22/1992
8 ITEMS: STARTING IN POSITION 1
COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME
1 AREA 4 20 F 8
5 PERIMETER 4 20 F 8
9 BRVEG11D# 4 10 B -
13 BRVEG11D-ID 4 10 B -
17 VEG2 5 5 C - CORRECT.TO.MAP
22 OP2 1 1 I -
23 VEG4 5 5 C - UPDATE.JUNE92
28 OP4 1 1 I -
** REDEFINED ITEMS **
17 VEGOP2 6 6 C -
23 VEGOP4 6 6 C -
The item VEG1 was deleted from the coverage before distribution. It
represents the vegetation code as originally digitized, before
corrections were made in December 1991. Similarly, the OP1 code
is obsolete.
VEG2 is the vegetation code as contained on the published map.
OP2 is the overprint code as digitized from the published map.
VEG4 is the vegetation code including the "best guess" for polygons
that are not labeled on the original map.
OP4 is the overprint code including the "best guess" for polygons
that are not labeled on the original map.
VEGOP2 is an item created with the INFO REDEFINE command, that
includes both the vegetation code VEG2 and the overprint
code OP2 as a single item.
VEGOP4 is a redefined item that includes VEG4 and OP4 as a single item.
15. The INFO file BRVEG11D.NAME contains text items that identify
the coded legend categories. Because the vegetation codes and
overprint codes are both necessary for an appropriate understanding
of the legend, the redefined items VEGOP2 or VEGOP4 should be used
for linking this file with the .PAT file. The items are:
ENTER COMMAND >SELECT BRVEG11D.NAME
94 RECORD(S) SELECTED
ENTER COMMAND >ITEMS
DATAFILE NAME: BRVEG11D.NAME 12/22/1992
8 ITEMS: STARTING IN POSITION 1
COL ITEM NAME WDTH OPUT TYP N.DEC ALTERNATE NAME
1 NAME.ID 4 4 I -
5 VEG 5 5 C -
10 OP 1 1 I -
11 GROUP 1 1 C -
12 GROUP.NAME 85 85 C -
97 SUBGROUP.NAME 20 20 C -
117 CLASS.NAME 40 40 C -
157 GROUP.SHORTNAME 30 30 C -
** REDEFINED ITEMS **
5 VEG2 5 5 C -
10 OP2 1 1 I -
5 VEGOP2 6 6 C -
5 VEG4 5 5 C -
10 OP4 1 1 I -
5 VEGOP4 6 6 C -
NAME.ID is an identifier, used to sort the vegetation and
overprint codes into the sequence used on the original map legend.
VEG2 is the vegetation code on the original published map.
OP2 is the overprint code on the original published map.
GROUP is a one character code that represents the major headings
on the original published map.
GROUP.NAME is the full name of the major headings on the original map.
SUBGROUP.NAME is the name of the subgroups on the original map. These
are often distinguished on the basis of the overprint code.
CLASS.NAME refers to the distinguishing type within the groups and
subgroups. The class names by themselves do not uniquely define
a legend category.
GROUP.SHORTNAME is an abbreviated version of the group name.
VEG4 is a redefined item that represents the vegetation code. It is
designed to be related to the VEG4 item in BRVEGGEO14D.PAT (see below).
The VEG4 item is implemented as a redefined item referencing the same
data as VEG2.
OP4 is a redefined item for overprint codes to be used with VEG4.
VEGOP2 is a redefined item that combines VEG2 and OP2 into a single
item. This is useful for relating the .NAME file to the .PAT file.
VEGOP4 is a redefined item that combines VEG4 and OP4 into a single item.
Records 92 and 93 of the file provide for the NOLAB vegetation code.
They will be referenced if VEGOP2 is used, but will not be referenced
if VEGOP4 is used as the relate item when relating to the .PAT
(see below).
Record 94 of the file provides for the OFFMA vegetation code. This
is a carryover from a previous analysis in which an OFFMAP category
was defined after an overlay with another map, and may be ignored or
purged.
16. The RELATE command in INFO may be used to relate the polygon attribute
table BRVEG11D.PAT to the names file BRVEG11D.NAME in order
to access the names associated with each polygon. For example,
to use the codes referring to the original map (including NOLAB codes),
the VEGOP2 item should be used as the relate item:
ENTER COMMAND >SELECT BRVEG11D.PAT
2141 RECORD(S) SELECTED
ENTER COMMAND >RELATE BRVEG11D.NAME 1 BY VEGOP2
ENTER COMMAND >LIST VEGOP2,$1GROUP.NAME,$1SUBGROUP.NAME,$1CLASS.NAME
1
VEGOP2 = 0
NO MATCH IN RELATED DATAFILE 1 FOR RECORD 1
GROUP.NAME =
SUBGROUP.NAME =
CLASS.NAME =
2
VEGOP2 =Dm 0
GROUP.NAME =FLORESTA OMBROFILA DENSA
SUBGROUP.NAME =FLORESTA AMAZONICA
CLASS.NAME =Montana
3
VEGOP2 =Tp 3
GROUP.NAME =SAVANA ESTEPICA
SUBGROUP.NAME =CAMPOS DE RORAIMA
CLASS.NAME =Parque
4
VEGOP2 =Ds 0
GROUP.NAME =FLORESTA OMBROFILA DENSA
SUBGROUP.NAME =FLORESTA AMAZONICA
CLASS.NAME =Submontana
5
VEGOP2 =Pf 0
GROUP.NAME =AREAS DAS FORMACOES PIONERIAS
MORE?N
ENTER COMMAND >
The message:
NO MATCH IN RELATED DATAFILE 1 FOR RECORD 1
is expected, and represents the "universe polygon" in the Arc/Info
coverage.
To use the "best guess" values that do not contain the NOLAB code,
use VEGOP4 as the relate item.
It is possible to use both items as relate items by doing two relates.
This example illustrates some of the polygons that were recoded between
VEG2 and VEG4.
ENTER COMMAND >SELECT BRVEG11D.PAT
2141 RECORD(S) SELECTED
ENTER COMMAND >RELATE BRVEG11D.NAME 1 BY VEGOP2 RO
ENTER COMMAND >RELATE BRVEG11D.NAME 2 BY VEGOP4 RO
ENTER COMMAND >RESELECT VEG2 = 'NOLAB'
58 RECORD(S) SELECTED
ENTER COMMAND >LIST VEGOP2,VEGOP4,$1GROUP.SHORTNAME,$2GROUP.SHORTNAME
96
VEGOP2 =NOLAB0
VEGOP4 =Da 0
GROUP.SHORTNAME =NO LABEL.
GROUP.SHORTNAME =FLORESTA OMBROFILA DENSA
132
VEGOP2 =NOLAB0
VEGOP4 =D 0
GROUP.SHORTNAME =NO LABEL.
GROUP.SHORTNAME =FLORESTA OMBROFILA DENSA
133
VEGOP2 =NOLAB0
VEGOP4 =LO 0
GROUP.SHORTNAME =NO LABEL.
GROUP.SHORTNAME =AREAS DE TENSAO ECOLOGICA
137
VEGOP2 =NOLAB0
VEGOP4 =D 0
GROUP.SHORTNAME =NO LABEL.
GROUP.SHORTNAME =FLORESTA OMBROFILA DENSA
145
VEGOP2 =NOLAB0
VEGOP4 =LO 0
MORE?N
ENTER COMMAND >
17. Suggestions on ways to improve this data base
would be appreciated.
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