SOP NUMBER: 94-01 Refuge Boundary Data (refbnd.txt)

Title: Process Description for Digitizing and Data Entry of Refuge BoundaryData

Working Group: Paul Steblein, Rick Schauffler, Frank Kenney, Greg Thompson, Sue Schaller, John Eaton, Aimee Trader

Effective Date: December 20, 1994

Last Revision: September 4, 1996

Purpose: Document the steps and procedures used to digitize refuge boundary data.

Description:

The standardized procedures will be tested on the following refuges: Parker River, Great Meadows, Prime Hook, Great Swamp, Montezuma, and Erie NWRs. All other refuges in Region 5 will be automated following the accepted procedures.

INTENT OF PROJECT

The goal of this project is to develop National Wildlife Refuge boundary data in a digital format for each refuge in Region 5 following standardized procedures. The intended application of the data is to serve as a spatial reference of refuge boundaries for other data layers in GIS and mapping applications. It is specifically not intended to be used as a land survey or representation of land for conveyance or tax purposes. The survey program in USFWS is developing cadastral information (boundary and acreage data) appropriate for legal purposes. It is expected that data created in this project will be replaced as better survey information is collected.

The objective is to provide digital lines of refuge boundaries developed with a consistent set of procedures, documented, and verified to the limits of the source information. The data will be appropriate for reference with other GIS datasets. Refuge boundaries will be made to conform to features on the USGS 1:24,000 scale. A disclaimer stating the limits of the data should accompany all presentations of the boundary data (e.g., "This refuge boundary data is intended only to be used as a spatial reference for 1:24,000 scale data, not for legal purposes. Legal survey data are available from Chief, Surveys and Maps, USFWS, 300 Westgate Center Drive, Hadley, MA 01035-9589")

SOURCE

The official source for refuge boundary data in this project are the mylar status maps located in the Region 5 Realty Office files. The scale of the maps vary as do the number of maps per refuge. Mylar copies of the original maps for each refuge will be transferred temporarily to the GIS lab for the purpose of manual digitization. The current exterior ownership boundary and the authorized legislative boundary will be digitized.

PROCESS

All data development work for the refuge boundaries will be conducted using Arc/Info software (ESRI, Redlands, CA) at the USFWS Region 5 GIS Lab (Holdsworth Hall, University of Massachusetts, Amherst, MA 01003). Final products for each refuge will include data projected in UTM (zones 17-19) NAD27 (datum) and documentation (FGDC spatial metadata). Available formats include Arc/info native format, Arc/info export, and AutoCAD DXF.

Geographic Extent of Coverages

Each refuge unit will be treated as a separate coverage and file. A refuge unit is considered all of the Service lands individually named as a refuge, or smaller land areas managed under adivision name. The Appendix I provides a list of all named refuge units (refuges and divisions), and corresponding 3-letter abbreviations. All arcs and polygons representing refuge boundaries will be labeled with these abbreviations.

Registration of USFWS Status Maps to the USGS 7.5' Quad base map.

1. Develop digital coordinates (also known as tics) for corners of appropriate USGS 7.5' topographic quad maps. Coordinates are entered as degrees, minutes, and seconds from the keyboard or text file, labeled, and projected as UTM NAD27.

2. Register each USGS quad map using the new tics and documenting RMS (root mean square). The registration process should be re-initiated if RMS error is greater than 0.005. Create new tics at locations that are identifiable on both USGS quad and on the USFWS refuge status maps (e.g., road intersections, Lat/Long reference lines). A minimum of 4 tics per map are required, but extras should be added covering the entire project area.

3. Register the USFWS refuge status map using the new tics. The RMS error should be 0.008 or less. If the error exceeds 0.008, test another combination of tics. The status maps are often ofdubious accuracy and undocumented. Road intersections may have moved since the development of the maps.

4. Digitize refuge lines from the USFWS refuge status maps. Minimize vertices on straigh stretches of boundary by placing a vertex at either end. The width of the lines on the statusmaps, at 1" = 1000', is about 10 meters. Set the weed tolerance to an appropriate level.

Fitting the Refuge Boundary Lines to the USGS 7.5' quad base map

1. Plot the raw boundary lines and tic marks at 1:24,000 scale on paper. Overlay the map on the appropriate USGS 7.5' quad map using a light table. Compare boundary lines to USFWS statusmap to ensure completeness.

2. Adjust boundary lines to conform to appropriate features on the USFWS status map. For example, if the status map shows the boundary of the refuge following the edge of a river, then the boundary line should be changed to follow the river on the quad map, regardless of whether it is the same shape on the status map.

Labeling Files and Geographic Features

1. Name the refuge boundary layer with the three-letter refuge unit abbreviation and bnd. For example, Iroquois NWR would be recorded as irobnd. Approved abbreviations are attached.

2. Develop line and polygon topology for refuge boundary data, i.e., "build" in Arc/info.

The respective commands would be:

build irobnd line

build irobnd poly

Assigning Attribute Information

1. Structure of attribute data for lines (arcs, stored in the AAT - arc attribute table) and polygons (polys - stored in the polygon attribute table) distinct from the variables created by default in ArcInfo:

Line Structure - AAT
	variable name	variablelabel	type	description
	boundary	boundary	5,5,c	type of boundary
	refuge unit	nwrunit	3,3,c	3-letter abbreviation assigned to smallest refuge division recognized by R5 Realty, Appendix I
	refuge name	nwrname	3,3,c	3-letter abbreviation of full refuge name, assigned by R5 Realty, Appendix I
	IFWS Number	ifwsno	5,5,c	Administrative number assigned to eachrefuge by Washington Realty, Appendix I

Polygon Structure - PAT
	variable name	variable label	type	description
	ownership status	status	5,5,c	nature of land ownership relative to the Refuge System
	refuge unit	nwrunit	3,3,c	3-letter abbreviation assigned to smallest refuge division recognized by R5 Realty, Appendix I
	refuge name	nwrname	3,3,c	3-letter abbreviation of full refuge name, assigned by R5 Realty, Appendix I
	IFWS Number	ifwsno	5,5,c	Administrative number assigned to each refuge by Washington Realty, Appendix I

2. Create additional variables (called items in Arc/info) in the AAT (arc attribute table) with the additem command: (This can be done with the codecheck AML, see below)

additem irobnd.aat irobnd.aat boundary 5 5 c

additem irobnd.aat irobnd.aat nwrunit 3 3 c

additem irobnd.aat irobnd.aat nwrname 3 3 c

additem irobnd.aat irobnd.aat ifwsno 5 5 c

3. Code arcs for the boundary item as follows:

l legislative- the approved legislative boundary for acquisition by USFWS;

o owned- the external boundary of currently owned land by USFWS;

e easement- boundary of land where easement or lease shares jurisdiction;

s secondary- secondary to other federal agencies;

p parcel- parcel lines representing units of acquisition, used especially for private in-holdings.

There are three cases where arcs are to be coded with double letters:

lo legislative/owned Where USFWS owns up to the legislative line.

le legislative/eased Where USFWS has an easement up to the legislative line.

oe ownership/easement The boundary between an owned tract and an eased one.

There is to be no space between the letters with double coded arcs. This is a change fromprevious SOPs. These arcs can be selected with logical expressions that utilize the cn operator (ArcInfo function - containing a substring of characters). For example, 'lo' defines an arc of aparcel that is owned by the refuge, and represents the edge of the legislative boundary. It can beselected by either sel boundary cn 'o (which will select boundaries of all owned land) or selboundary cn 'l (which will select the entire legislative boundary).

The polygon code 's, secondary to federal agencies, 'x, exclusion and 'u, uncertain status, arenot double-coded in the AAT. The edge of an 'x polygon is, by definition, a legislative boundary and 's and 'u will simply take the code of the feature that they adjoin, i.e. the line between anowned parcel and a secondary parcel would be coded 'o.

4. Code arcs for the nwrunit, nwrname, and ifwsno items as follows:

Code all arcs in the cover to the 3-letter abbreviations for division (nwrunit), refuge (nwrname)and the administrative number assigned to each refuge by Washington Realty (ifwsno), as listed in Appendix 1. This can be done using the codecheck AML, and if the cover contains several divisions then they can be coded separately using the select many or select box commands.

4. Add status as an item to the PAT (polygon attribute table).

additem irobnd.pat irobnd.pat status 5 5 c

additem irobnd.aat irobnd.aat nwrunit 3 3 c

additem irobnd.aat irobnd.aat nwrname 3 3 c

additem irobnd.aat irobnd.aat ifwsno 5 5 c

5. Code polygons using the status item and the same codes listed below.

l legislative- an area within the approved legislative boundary for acquisition by USFWS;

o owned- land currently owned by USFWS;

e easement- land where easement or lease shares jurisdiction;

s secondary- secondary to other federal agencies;

x exclusion- area internal to a closed legislative polygon that is excluded from acquisition;

u uncertain- status of parcel is uncertain because it is unknown, disputed, or requires additional research in Realty.

Polygons should be assigned a single code at this point. If a new situation arises, such as a partial undivided interest in a parcel, then a new code will be developed to meet the need.

There are menus for coding both arcs and polys in the tools directory. They are calledcodeline.menu and codepoly.menu. Calling codeline first will give you a button that calls codepoly. They allow you to select a group of arc or poly features and then "calc" them to the accepted codes. They also call a couple of AMLs, also in the tools directory, showcodel.aml forarcs and showcodep.aml for polys that select for all the accepted codes and display them indifferent colors. Arcs or polys that are uncoded are shown in red. The stray code AMLs onlylook for uncoded and unacceptably coded arcs.

To make a final check of the coding for accuracy and completeness there is an AML called codecheck.aml in the tools directory. Run it from the directory that contains the refuge that youare working on by typing &r ../tools/codecheck, and it will allow you to choose any cover in that directory and view the records for boundary in the aat, as well as all the other items in both the AAT an PAT. It allows you to go into ArcEdit and view or change coding interactively, using the above mentioned menus and AMLs, and gives you the option to build and export the cover when you are done.

Quality Control

Boundary data will be verified for spatial and thematic integrity at each phase of the project (Appendix I). First, initial digitizing will be processed at the USFWS R5 GIS Lab - the USFWS status map is the primary reference for development and verification of boundary data (complete line work and thematic coding). Second, the Realty Mapping Section will plot the data at 1:24,000 scale to verify against appropriate USGS 7.5' topo quad maps. The individual plots are registered to the USGS map, and vectors marked for re-digitizing if they are incomplete or deviate from appropriate spatial features. The plot is then verified against the USFWS statusmap for completeness and accuracy of attribute labels. Questions or issues that develop related to ownership status are referred to senior Realty staff for resolution.

Third, the marked-up 1:24,000 test plots are returned to the Lab for editing the original Arc/info files. The edited boundary data are plotted by Mapping, reviewed a second time by Mapping (returned to Lab for editing if not acceptable), and sent to the Refuge Manager with USGS 7.5 topoquads for final review and verification. Any changes marked by the Refuge Manager are corroborated or researched by Realty, and edited at the Lab. Once the Refuge Manager has signed-off on the boundary, the data will be available for distribution.

An estimate of spatial error will be calculated for refuge boundary data derived from USFWS status maps. Coordinates for a minimum of five refuge boundary corners at five refuges will be calculated with GPS receivers (targeting 1-2m accuracy). The coordinates for those same corners will be extracted from data digitized from status maps to calculate error.

When appropriate, data formats will adhere to the Cadastral Data Content Standards, April 1994 (Federal Geographic Data Committee).

Data Documentation and Distribution

A text file is created with the initiation of each refuge unit to be used as a data "journal". The name of staff developing the data, dates, characteristics of source materials, and all departures from the procedures and adjustments to the data will be documented in the text file (xxxbnd.txt). Final documentation to accompany the data will follow the Federal Geographic Data Committee standard for spatial metadata. A comment field was added to the FGDC documentation to add information stored in the data journal. Copies of the spatial metadata will be filed with Realty, submitted to the USFWS data clearinghouse, and accompany any data that are distributed.

No data will be distributed without completion of the verification and documentation. Copies of the products will be stored at the R5 Cartography & Spatial Data Services Branch Office.

Contact for Standards and Data:
Linda Shaffer
Supervisory Cartographer US Fish & Wildlife Service
Cartography & Spatial Data Services
300 Westgate Center Drive
Hadley, MA   01035