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: firstname.lastname@example.org 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.
Last modified: 2 November 1998.