Geographic Information Metadata for the Manitowoc County Coastal Wetlands Project

Water Resources Management Practicum

Institute for Environmental Studies

University of Wisconsin-Madison

August 31, 1998

Prepared by: David Blough, GIS Consultant, Land Information Computer Graphics Facility, University of Wisconsin-Madison and Jeffrey Ripp, WRM Student, University of Wisconsin-Madison.

• OVERVIEW
  • Software Requirements
  • Disclaimer
• PART 1: GIS PROJECT FOLDERS
  • Installing the GIS
  • Coordinate System and Map Projection of the Project
• PART 2: WETLAND DATA THEMES
  • The Wetlands Data Layers
  • Attributes for Wetland Data Layer
• PART 3: REFERENCE DATA LAYERS: SHORELINE BUFFERS
  • The Shoreline and Buffer Data Layers
  • The Land Use Data Layer
• PART 4: REFERENCE DATA LAYERS: GEO83 FOLDER
  • Bluff Stability Study
  • County Boundary
• PART 5: REFERENCE DATA LAYERS: ORTHOPHOTOS
  • Background on USGS Digital Orthophoto Quadrangle
• PART 6: REFERENCE DATA LAYERS: THE TIGER DATA
• PART 7: FISCHER CREEK PARK DATA

This document describes the ArcView 3.0 Geographic Information System (GIS) application prepared by the Water Resources Management (WRM) Practicum, for the coastal wetland study in Manitowoc County. The goal of this document is to provide metadata for the geographic data prepared for the WRM Practicum, emphasizing the various sources of data and the steps taken to prepare the project files for use by the WRM students. The final ArcView project files were compiled for use by natural resource managers in Manitowoc County. These project files have been submitted to the county on a compact disk.

This document is organized into sections based on the thematic content and sources of data prepared for the practicum. Where appropriate, reference is made to metadata documents provided with the original data sources.

Software Requirements

The 1998 WRM GIS for the coastal wetlands of Manitowoc County was developed for ArcView 3.0 (Windows 3.1/Windows NT). The metadata documents included on the CD ROM are in Microsoft Word 6.0 format.

Microsoft Access '97 database was used to capture information from the assessments and inventories compiled in the field. Useful attributes where taken from this database to create a coastal wetlands coverage for Manitowoc County. Additional information about each wetland is available in this database.

Disclaimer

The geographic data used in this project were taken from a variety of sources and combined to create a spatial data set for coastal wetlands in Manitowoc County. The 1998 Water Resources Management Workshop accepts no responsibility for the accuracy of this data. The wetland data theme prepared by the Workshop is based on the WDNR's Wisconsin Wetland Inventory and contains wetland polygons created using digital orthophotos. Because wetland polygons exhibited in this data theme do not represent actual delineated wetlands, this information should not be used for regulatory purposes.

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PART 1: GIS PROJECT FOLDERS

The data layers used by the 1998 WRM Practicum are stored on a CD-ROM in several folders. The /wrmgis/ folder contains county-wide information about coastal wetlands in Manitowoc County. The /fischer/ folders contains geographic data specific to Fischer Creek Park, in the southern portion of the county. These themes can be viewed using ArcView project files in each of these folders.

The contents of the /wrmgis/ folder are shown in Table 1.

Table 1: Contents of /WRMGIS/ Folder
Name	Type	Description
wrmgis.doc	MS Word 6.0 document	This document, describing metadata for the GIS project.
wetlands.apr wetlands1.apr wetlands2.apr wetlands3.apr	ArcView 3.0 project files	ArcView project files for viewing WRMGIS data layers. This project file includes overviews of the county and the wetlands assessed during the course of the summer field work.
*.avl	ArcView legend files	ArcView legend files created for use with the wetland project files.
*.prj	Text Fiels	ASCII text files used by ArcInfo for reprojecting coverages.
wetland.mdb	Microsoft Access	Database of information compiled in the field.
/doq_n/	Folder	Contains USGS digital orthophoto quarter-quads, WRM study area
/geo83/	Folder	Contains data layers in geographic coordinates, NAD83 datum
/tiger/	Folder	Contains census TIGER data, geographic coordinates, NAD83 datum

Subsequent sections of this document describe the data layers contained in the project folders (doq_n, geo83, tiger and fischer).

Table 2: Contents of the /FISCHER/ Folder
Name	Type	Description
fischer.apr	ArcView 3.0 project file	ArcView project file for viewing Fischer Creek Park data layers.
*.avl	ArcView 3.0 legend files	Legend files for use with fischer.apr
/doq_n/	Folder	Contains USGS digital orthophoto quarter-quads for Fischer Creek area.
/geo83/	Folder	Contains data layers in geographic coordinates, NAD83, datum.
/tiger/	Folder	Contains census TIGER data, geographic coordinates, NAD83 datum
/shape/	Folder	Contains ArcView shape files created by the WRM workshop, including vegetation map, location of sampling sites, etc.

Subsequent sections of this document describe the contents of the data folders.

Installing the GIS

To use the geographic data, it is necessary to copy the entire /wrmgis/ or /fischer/ folder to a permanant drive (e.g., hard drive). Simply copy the entire directory to the desired drive. Once the files have been copied (including all subdirectories under the /wrmgis/ folder), it is necessary to set the correct path in each of the ArcView projects so the projects can locate the required information.

Currently both the wetland.apr and fischer.apr files look for data in "u:/wrm98/wrmgis/". When the wrmgis folder is moved to a different location, the path must be changed. An easy way to do this is as follows:

1. Make a copy of the project file(s) [.apr files]
2. Open the copy using a text editor such as Notepad or WordPad
3. Use the search and replace feature to locate the text string, "u:/wrm98/wrmgis/" and replace it with the new path, for example, "d:/data/wrmgis/"
4. Save the changed copy of the project file

The fischer.apr file looks for data under "u:/wrm98/wrmgis/fischer/". Again, use a search and replace to find this string and replace it with the proper string.

Note: even in a DOS/Windows environment, forward slashes (/) are used in the ArcView project file path.

Coordinate System and Map Projection of the Project

Geographic data in the /wrmgis/ folder exists in two different coordinate systems. The raster image data - the orthophotos located in the doq_n folder - are in the Universal Transverse Mercator (Zone 16) coordinate system, measured in meters, referenced to the North American Datum of 1983 (NAD83). The vector data, found in the tiger, geo83 and fischer folders, are projected in geographic coordinates, decimal degrees of latitude and longitude, on the NAD83 datum.

The Views of the ArcView projects display all the geographic data in the UTM16 projection. ArcView is capable of reprojecting vector data on the fly, provided the source data is in geographic coordinates. It cannot reproject image data, however. For this reason, the vector data is provided in geographic coordinates, so that it can be reprojected with ease if desired. The Views are set for UTM16 to project the vector data in the same coordinate system as the raster image data. For more information, see the section on the Orthophoto Data Layer.

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PART 2: WETLAND DATA THEMES

Table 2 below describes the coverages present in the /wrmgis/geo83 folder. Other coverages present in the /tiger/ and /doq_n/ folders are described in later sections.

Table 3: Contents of /WRMGIS/GEO83/ Folder.
Coverage Name	Format	Source	Description
center	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
intermit	ArcInfo 7.0	Bay Lakes RPC	Intermittent streams
lmshore	ArcInfo 7.0	GLERL	Shoreline for Manitowoc, Sheboygan and Kewaunee Counties
manitcty	ArcInfo 7.0	WDNR	County Boundary
manitow	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
manrap	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
mishic	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
mshorbf	ArcInfo 7.0	GLERL	2000' shoreline buffer
mshor1000	ArcInfo 7.0	GLERL	1000' shoreline buffer
mshorbf2	ArcInfo 7.0	GLERL	2250' shoreline buffer
mshorbf3	ArcInfo 7.0	GLERL	2500' shoreline buffer
mshore	ArcInfo 7.0	GLERL	Shoreline for Manitowoc County (clipped)
newt_1	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
newt_2	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
pcenter	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
perennl	ArcInfo 7.0	Bay Lakes RPC	Perennial streams
pmanitow	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
pmanrap	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
pmishic	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
pnewt_1	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
pnewt_2	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
ptwocree	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
ptworiv	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
pwetlnd1	ArcInfo 7.0	WDNR WWI	Wetland inventory for coastal zone (edge matched)
pwetland.shp	ArcView Shape File	WDNR WWI	WRM modified point wetlands coverage (<2 acres)
shorec	ArcInfo 7.0	Bay Lakes RPC	Shorline land use
shrline	ArcInfo 7.0	Bay Lakes RPC	Shorline for Manitowoc, Sheboygan and Kewaunee County.
twocree	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
tworiv	ArcInfo 7.0	WDNR WWI	Wetland inventory tile
mwatrshd	ArcInfo 7.0	WDNR	Major watershed boundaries
wetland1	ArcInfo 7.0	WDNR WWI	Wetland inventory for coastal zone (edge matched)
wetland.shp	ArcInfo 7.0	WDNR WWI	WRM modified wetland coverage (polygons)

The Wetlands Data Layers

The most important GIS layers produced by the 1998 WRM Practicum are the wetlands data layers. The layers were derived from the 1989 Wisconsin Department of Natural Resources (WDNR) Wisconsin Wetlands Inventory (WWI). Metadata for these files is availabe from the Wisconsin Department of Natural Resources world wide web site at http://www.dnr.state.wi.us/org/at/et/geo.

Four complete wetland coverages are provided in the /wrmgis/geog83/ folder. The original WDNR files ArcInfo coverages (wetlnd1 and pwetlnd1) are included along with the modified ArcView shape files (wetland.shp and pwetland.shp) prepared by the 1998 WRM Practicum for Mantiwoc County. The original tiles from the Wisconsin Wetland Inventory are also included.

Creating Wetlands Layers from WIDNR Wetland Coverages

The WRM project needed a single wetlands data layer for the study area, so that each wetland could be assigned a WRM identification number for field research. The source data for wetlands - from the WDNR's Wisconsin Wetlands Inventory - is organized into two ArcInfo coverages. A polygon coverage (wetlnd1) outlines the larger wetlands, and a point coverage (pwetlnd1) records the smaller wetlands, which are less than 2 acres. These two coverages were obtained from the WDNR as tiles to make them more manageable. Table 3 shows the tiles which overlap the WRM study area, and how they were renamed for preliminary use in the WRM study:

Table 4: Wisconsin Wetlands Inventory Source Data
Coverage	Custodian	Data Date	Projection	WRM name*	Reprojected**
t41723pf	WDNR	1989	WTM-27	center	GEO83
t41823pf	WDNR	1989	WTM-27	newt_1	GEO83
t41824pf	WDNR	1989	WTM-27	newt_2	GEO83
t41923pf	WDNR	1989	WTM-27	manrap	GEO83
t41924pf	WDNR	1989	WTM-27	manitow	GEO83
t42025pf	WDNR	1989	WTM-27	twocree	GEO83
t42124pf	WDNR	1989	WTM-27	mishic	GEO83
t42024pf	WDNR	1989	WTM-27	tworiv	GEO83
t41723tf	WDNR	1989	WTM-27	pcenter	GEO83
t41823tf	WDNR	1989	WTM-27	pnewt_1	GEO83
t41824tf	WDNR	1989	WTM-27	pnewt_2	GEO83
t41923tf	WDNR	1989	WTM-27	pmanrap	GEO83
t41924tf	WDNR	1989	WTM-27	pmanitow	GEO83
t42025tf	WDNR	1989	WTM-27	ptwocree	GEO83
t42124tf	WDNR	1989	WTM-27	pmishic	GEO83
t42024tf	WDNR	1989	WTM-27	ptworiv	GEO83

*Names beginning with "p" denote point coverages.

**Coverages were reprojected for preliminary analysis.

The tiles listed in the table above were appended together to create two wetlands layers encompassing the WRM study area: a polygon coverage (wetlnd1) and a point coverage (pwetlnd1). To ensure greatest accuracy, the tiles were appended in their original projection and datum (Wisconsin Transverse Mercator, NAD27). Once the tiles were appended, the boundaries between tiles were removed, the coverages were edited and cleaned, and topology was rebuilt. Then, the two wetlands coverages were projected into geographic coordinates, decimal degrees, on the NAD83 datum. An attribute field (WRM-id) then was added to each coverage so that the WRM id number of each wetland could be recorded.

Appending the Polygon Wetland Tiles

Before appending, the wetland tiles were examined in ArcEdit. The wetland tiles lined up fairly well, so no edge matching or rubber sheeting was necessary to create the appended coverage. Tic id numbers were unique among tiles - they appeared to be based on town section numbers - but feature ids were not unique: the range of id numbers overlapped from tile to tile. Therefore, the tiles were appended to offset feature id numbers, and keep all feature attributes. The following command was used:

APPEND <out_cover> {template_cover} {FEATURES}

The resulting coverage was CLEANed to restore topology. Then, the boundaries between tiles were removed by dissolving the arcs between polygons with the same wetland code. (In the wetlands tiles, all polygons have an wetland code representing either the type of wetland or the type of other feature. Wetlands have codes like TK3; non-wetland polygons are coded U.) The dissolve command was specified as:

DISSOLVE <in_cover> <out_cover> <dissolve_item> {POLY}

DISSOLVE test1c test1d WETCODE POLY

This dissolves tile boundaries, but loses all attributes other than WETCODE. The resulting coverage had some errors outside the WRM study area but within the larger area covered by the original tiles. These errors were one dangling arc and one sliver polygon too large to be corrected by CLEAN. These were edited manually in Arcedit, and the BUILD command in Arc was used to restore topology.

Appending the Point Wetland Tiles

A simpler procedure was used to create the point coverage (pwetlnd1). Cleaning the coverage and dissolving tile boundaries were not necessary because no tile boundaries existed in the point wetland tiles. The tiles were appended as above, and then point topology was built.

BUILD <in_cover> <out_cover> {POINT}

Because DISSOLVE was not performed, the point wetland coverage (pwetlnd1) retains all the feature attributes of the original point wetland tiles. Note though, that none of the point wetland tiles had the feature attribute WETCODE as in the polygon wetland tiles.

Projecting the Wetland Coverages

The point and polygon wetland coverages were projected from WTM27 to geographic coordinates, decimal degrees, on NAD83. The projection file is available on request. The polygon coverage was rebuilt using the BUILD command after being projected.

Adding an Attribute for the Water Resource Management ID Number

Once the two wetlands coverages were projected into geographic coordinates, an item was added to each coverage's feature attribute table so that each wetland could be assigned an id number corresponding to its id number in the WRM Practicum's database. The item was named WRM-id and consists of 6 characters (letters and/or numbers).

ADDITEM <in_info_file> <out_info_file> <item_name> <item_width> <output_width> <item_type> {decimal_places} {start_item}

ADDITEM wetlnd1.pat wetlnd1.pat WRM-id 6 6 C

ADDITEM pwetlnd1.pat pwetlnd1.pat WRM-id 6 6 C

Converting the ArcInfo Wetland Coverages to ArcView Shape Files

The revised Wisconsin Wetlands Inventory coverages wetlnd1 and pwetland1, were converted to ArcView shape files for editing and inclusion in the final GIS product. These coverages were converted into shape files because ArcView allows for easy editing and updating of polygon and point features, as well as attribute tables. The final shape files are included in the /wrmgis/geo83/ folder as wetland.shp and pwetland.shp.

Editing Wetland Shape Files

Once the wetland coverages were converted to shape files, it was necessary to edit the coverages to reflect what was observed in the field during the study. This included labelling polygons with the appropriate WRM wetland identification number, digitizing polygons for some wetlands and adding attributes to record observations made in the field.

1. Assigning Wetland IDs

In the wetland.shp file, each wetland polygon within the study zone was assigned a value for the wrm_id attribute, ranging from 1 to 57. Wetland polygons that fell within the study zone but were not assessed (e.g., Point Beach) were assigned an id of "99". Polygons that fell outside of the zone were not assigned an id. Because many of the wetlands consist of more than one polygon, the wrm_id is not unique. In fact, many of the wetlands consist of several polygons because the WWI classified polygons according to vegetation communities. The boundaries between the polygons for each wrm_id were not dissolved in order to preserve the DNR's classification information for each polygon.

The point wetland ArcInfo coverage (pwetlnd1) was also converted to a shape file called pwetland.shp. This coverage represents all wetlands in the study area that are less than 2 acres in size. Each point within the study zone was labelled with the appropriate wetland id in the wrm_id field. Wetlands that were not assessed were assigned a wrm_id of "99". Wetlands outside the zone are null. All of the original attributes included in the WDNR WWI are preserved in this shape file.

2. Digitizing Wetlands

Several of the coastal wetlands included in this study either did not exist as polygons in the original wetlnd1 ArcInfo coverage or were shown as groups of wetlands that were less than 2 acres in the pwetlnd1 coverage. In some cases, wetland polygons were created to correspond more closely to the wetland evalutated during the study. Thus, several polygons were created in order to have each wetland in the study represented in the final shape file. Therefore, it is important that the wetland polygons depicted in the wetland.shp file be used only for non-regulatory purposes. These polygons do not necessarily represent official wetland delinations. Polygons were created for the following locations and wrm_ids:

Pine Creek (wrm_ids: 28, 29, 30)

Silver Creek (wrm_ids: 23, 27)

Point Creek (wrm_id: 45 - expanded from existing polygon)

WEPCO (wrm_ids: 3, 4, 5, 6, 8)

All of these polygons were digitized using ArcView and the digital orthophotos provided in the data set. These polygons have the value of "WRM" in the "digitized" attribute of the wetland.dbf file.

It was also necessary to split the polygon for the East and West Twin Rivers because the entire river corridor was shown as a single polygon in the original WWI. To accomplish this, a line was drawn at the mouth of the combined river outlet which effectively split the polygon into two basins.

Attributes for Wetland Data Layer

The attributes contained in the original WWI inventory are preserved in the wetland.shp shape file. Several other attributes were added to the wetland.dbf file to reflect data collected in the field. Table 4 lists the attributes found in the wetland shape file.

Listed below are the allowable values for each of the WRM created attributes for the wetland.shp coverage. This data is stored in the wetland.dbf file.

COAST_ZONE

1= <1000 feet from coast

2= between 1000-2000 feet from coast

3= greater than 2000 feet from coast

4= not assessed

WRM_TYPE

Barrier/lagoon

Coastal canyon

Depressional

Restricted outlet

Ridge/swale

Ridge/swale remnant

Riverine

Slope

VEG_TYPE

Cedar swamp

Disturbed emergent open marsh

Disturbed open canopy

Mixed hardwood/conifer/shrub canyon

Not surveyed

Sedge meadow

Unclassified Mosaic

OWNER

Single Private

Multiple Private

Public

Quasi-Public

Mixed Public & Private

MISC. FUNCTIONAL VALUES (water quality, human uses, etc.)

High

Medium

Low

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PART 3: REFERENCE DATA LAYERS: SHORELINE BUFFERS

The Shoreline and Buffer Data Layers

One map layer needed for the WRM project is a 2000 ft buffer around the shoreline in Manitowoc County. One possible source for this shoreline buffer is a shoreline coverage provided by the Great Lakes Environmental Research Laboratory (GLERL). This Medium Resolution Vector Shoreline data was compiled for the Great Lakes and St. Lawrence River from aerial photography dating 1987-1989. Their metadata report indicates that the scale varies from 1:24,000 to 1:250,000. U.S. data was received from the U.S. Army Corps of Engineers, Detroit District. Under Use Constraints, the metadata document states, "The vector data are intended for general planning, study, and illustrative purposes. The data are not intended for uses that require a high degree of positional accuracy." This data set is available from GLERL's web site at http://www.glerl.noaa.gov/.

Another source of shoreline data is the WIDNR's Wetland Inventory coverages. The WIDNR coverage was created by delineating wetlands on orthophotos from 1989, and is usable at a scale of 1:24,000. The coastal tiles of the Inventory include polygon boundaries which define the shoreline.

The WRM Practicum compared the WIDNR Wetland Inventory and the GLERL coverages against USGS Orthophoto backdrops. The two vector coverages differed along the shoreline by at least 115 ft in some spots, or roughly 5% of the buffer defining the WRM study area. Although neither coverage followed the shoreline exactly, the WIDNR coverage tends to appear inland of the observed shore. Buffering the WIDNR shoreline errs on the side of increasing the study area. However, separating the shoreline out of the WIDNR coverage was time consuming and not justified since it appears no more accurate overall than the GLERL coverage.

An alternative way to address the potential errors is to create several shoreline buffer zones of different widths. Thus, four buffer zones were created from the GLERL shoreline: mshr1000 at 1000 ft; mshorebf at 2000 ft; mshorebf2, at 2250 ft; and mshorebf3, at 2500 ft. All are available in the /wrmgis/geog83/ folder. These files are useful for comparing differences between different definitions of the shoreline. For most of the Views in the ArcView projects, the mshorebf3 is used as a conservative estimate of the WRM coastal zone, due to the imprecision of the GLERL shoreline coverage.

Table 6: File History of the GLERL Shoreline Coverage
Name (Format)	Description	Source	Source Date	Scale	Projection/ Datum
manitowac.e00 (ArcInfo export file)	Medium Resolution shoreline of Manitowoc County	GLERL	1987-1989	1:24,000 - 1:250,000	Albers Equal Area Clarke 1866 [NAD27]

The coverage was imported into ArcINFO, projected into geographic coordinates on the NAD83 datum (using alb_geo83.txt), renamed mshore, and copied to the geo83 workspace.

Buffering the GLERL coverage:

The BUFFER command in ArcINFO uses a two-dimensional algorithm to calculate a buffer at a user-specified distance from the shoreline. The buffer distance is specified in map units. Since coverages with geographic projections have decimal degrees as map units, and since the geographic coordinate system is implicity three-dimensional, such coverages should be projected into the two-dimensional coordinate system that best suits the study area before running the BUFFER operation.

The GLERL coverage was projected from geographic coordinates to Manitowoc County coordinates, including the appropriate datum adjustment, storing the newly projected coverage in the mani91 workspace. The projection file is available on request. The mani91\mshore coverage was then buffered as follows:

BUFFER mani91\mshore mani91\mshorebf # # 2000 # LINE ROUND FULL

All of the options are defaults except for the buffer distance of 2000 ft. (Manitowoc County coordinates are in map units of feet.) The buffered shoreline was projected back to geographic coordinates for ease of viewing in ArcView against orthophoto backdrops. The buffered shoreline in geographic coordinates is stored as /geo83/mshorebf.

The additional buffers at 1000, 2250 ft and 2500 ft were created using the same procedure, and named geo83/mshr1000, geo83/mshorebf2 and geo83/mshorebf3.

The Land Use Data Layer

One characteristic of interest to the WRM Practicum was the existing land use around coastal wetlands. A recent, large-scale classification of land use along parts of the Lake Michigan coast is available from a Bluff Stability/Bluff Erosion Study done in cooperation with Dr. David Mickelson of UW-Madison, Bay-Lake Regional Planning Commission, and others. The geographic data used in the Bluff Stability Study, provided by Bay-Lake RPC, contains a coverage classifying land use into several categories including residential, commerical, industrial, natural areas, agriculture, and so on. The classification was compiled from aerial photography at 1"=400' scale verified by fieldwork carried out in 1996. For more information, see Part 4: "Additional Reference Data Layers in GEO83 - Bluff Stability Study" and the metadata document provided with the Bluff Stability Study data. While this coverage is useful, it is not complete for the Manitowoc County shoreline.

Land use data in the Bluff Stability study is in the form of a PC/ArcINFO coverage, an ArcView legend (lusumry.avl), and a text file explaining land use classification codes. For use in the WRM project, the data was converted to an ArcINFO coverage and a new legend (lugenrl.avl) was constructed to display fewer, more general categories of land use. The coverage provided to the WRM Practicum is named shorec and is available in the geog83 folder.

Converting PC/ArcINFO Coverages to ArcINFO Coverages:

PC/ArcINFO coverages differ from ArcINFO coverages in at least two ways. First, numbers are stored in single precision instead of double precision. This means that in some coordinate systems, the left-most digit of the x- and y- coordinates are subtracted off to allow for greater precision. (For example 486123.456 could become 86123.4567.) This XSHIFT and YSHIFT is not as necessary in a double precision coverage. Second, PC/ArcINFO coverages store attribute information in dbase files (*.dbf) rather than INFO files.

The most reliable way to convert from PC/ArcINFO to ArcINFO is to use ArcINFO's export format. This means EXPORTing the coverage from PC/ArcINFO - creating an *.e00 file - and then IMPORTing the coverage into ArcINFO. The PC/ARCINFO coverages provided in the bluff stability study were exported using the DOUBLE option to set them to double precision:

EXPORT double shorec shorec

This takes the PC/ArcINFO coverage shorec and creates the interchange file shorec.e00. The interchange file was then imported into ArcINFO using the following command:

IMPORT auto shorec temp\shorec

which creates the ArcINFO coverage shorec from shorec.e00. (Note that if you use the same coverage name, you must put the new one in a different workspace.)

Projecting the land use coverage using PROJECT:

The shorec coverage was projected from its original projection and datum of WTM27 to geographic coordinates, decimal degrees, NAD83. The projection file is available on request. Polygon topology was restored with the BUILD command, and the resulting coverage was copied to the geog83 folder.

Creating a more general land use classification:

The land use coverage came with an legend (lusumry.avl) for displaying land use categories in ArcView. Since a more general classification was desired, the legend was edited in ArcView and saved as lugenrl.avl.

Table 7: Comparison of Legends for Land Use Coverage
lusumry.avl		lugenrl.avl
LU field	Description	LU field	Description
110	Single Family Residential	100 - 199, 735	Residential
130	Two Family Residential
180	Mobile Home
200 - 298	Commercial	200 - 699	Commercial/Industrial
300 - 398	Industrial
417	Off Street Parking
500 - 599	Communications/Utilities
600 - 699	Governmental/Institutional
700 - 799	Outdoor Recreation	700 - 799	Outdoor Recreation
735	Lawns/Yards
805	Vacant/Open Space	805	Vacant/Open Space
810 - 899	Agriculture	810 - 899	Agriculture
910 - 915	Lakes/Ponds	910 - 915	Lakes/Ponds
950 - 952	Natural Areas	950 - 952	Natural Areas
955	Bluffs/Beaches	955	Bluffs/Beaches

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PART 4: REFERENCE DATA LAYERS:GEO83 FOLDER

Bluff Stability Study

Creating ArcINFO coverages from AutoCad drawing layers

Autocad drawings are in a different data format from ArcView shapefiles or ArcInfo coverages. However, ArcView comes with a Cad Reader extension allowing Autocad drawings to be viewed. To use this extension, select it under File/Extensions when the project window is active. Further, a free Cadtools Extension (cadtools.avx), which converts Autocad drawings to ArcView shapefiles, is available from ESRI's web site under User Scripts (www.esri.com or andes.esri.com/arcscripts/). To add this extension to ArcView, copy the file (cadtools.avx) to the directory location referenced by the ArcView parameter AVEXT. (Under Windows NT or 95, AVEXT references $AVHOME\ext32, which often translates to c:\esri\av_gis\arcview\ext32.) Then select the extension in the File/Extension menu of the project window.

Cadtools Extension allows the user to separate out different layers of an Autocad drawing and save them as ArcView shapefiles, using the Make Cad Layers feature. These polyline shapefiles can then be converted to ArcInfo coverages using the SHAPEARC command in ArcInfo.

Layers extracted from the Bluff Stability Study

For the WRM Practicum dataset, three layers were extracted from the Bluff Stability Study. These were shorline, intermit, and perennl: the shoreline, intermittent streams, and perennial streams, rivers, and lakes within the entire study area of the Bluff Stability Study.

Once converted to ArcInfo coverages, these three coverages were projected from their original coordinate system of WTM27 to geographic coordinates, decimal degrees, NAD83, and were stored in the geog83 workspace.

Because the extent of the intermit and perennl coverages is larger than Manitowoc County, it was necessary to add attributes to the tables that allow for querying those features of interest. The following two attributes were added to the perennl coverage: "name", which gives the name of the perrenial river and "manitowoc" which is given a value of "Y" or "N" depending upon if the river is located within Manitowoc County. The attribute "manitowoc" was also added to the intermit coverage, signifying if the intermittent stream lies within county boundaries.

County Boundary

For reference purposes, a coverage of the Manitowoc County boundary is provided in the /geo83/ folder. This coverage was taken from the Department of Natural Resources' archives.

Table 10: County Boundary Information
Coverage (format)	Original Name	Description	Custodian	Projection
Manitcty (ARC interchange)	Manitcty.e00	Manitowoc County Boundary	DNR	WTM83

No metadata was provided with the export file manitcty.e00. This coverage was imported into ArcINFO, into the workspace wtm83\manitcty. The DESCRIBE command gave information on the projection and datum of the coverage, confirming that it was in WTM83. This coverage was reprojected into geographic coordinates, NAD83 and was named manitcty and located in the geog83 folder.

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PART 5: REFERENCE DATA LAYERS: ORTHOPHOTOS

Orthophotos for the WRM practicum were taken from the USGS Digital Orthophoto Quadrangle series. They are located in the doq_n folder. More information on USGS DOQs is available in the documentation on the source CD-ROM, available at the Wisconsin Land Information Computer Graphics Facility at the University of Wisconsin Madison and from the USGS Geographic Data Spatial Node at http://water.usgs.gov/public/GIS.

Background on USGS Digital Orthophoto Quadrangle (taken from USGS documentation (DOQINFO.TXT))

USGS STANDARD DIGITAL ORTHOPHOTO QUADRANGLES

The primary digital orthophoto quadrangle (DOQ) is a 1-meter ground resolution image covering an area 3.75 minutes of latitude by 3.75 minutes of longitude at a scale of 1:12,000, cast on the Universal Transverse Mercator projection on the North American Datum of 1983 (NAD 83). The DOQ has between 50 and 300 meters of overedge, sufficient to facilitate tonal matching for mosaicking and the placement of NAD 83 and North American Datum of 1927 quarter-quadrangle corner ticks that are embedded in the image.

Through image mosaicking two or more rectified images can be combined and merged into one image. For instance, a digital orthophoto in 7.5-minute format can be produced by mosaicking four DOQ's.

The DOQ is formatted as four ASCII header records, followed by a series of 8-bit binary image data records. The radiometric image brightness values are stored as 256 gray levels. The approximate file size for a DOQ is 55 megabytes. [In compressed form, the file size is approximately 2.9 megabytes.]

The metadata in the DOQ header records contain descriptive information about the image including photographic source type, date, instrumentation used to create the DOQ, and information relating to the digital elevation model used in the rectification process."

USGS DOQ Names for Manitowoc County:

All of the images are in JPEG format. The datum is NAD83, the coordinate system is UTM Zone 16 and map units are meters.

Table 11: USGS Digital Orthophotos Used in the 1998 WRM Practicum
Quarter-Quad Name	USGS Image File/Header File	Renamed Image File/World File*
CLEVELAND EAST NW	O4308703.NWC/NWH	CLEVENW.JPG/JGW
CLEVELAND EAST SW	O4308703.SWC/SWH	CLEVESW.JPG/JGW
MANITOWOC NE	O4408759.NEC/NEH	MANINE.JPG/JGW
MANITOWOC SE	O4408759.SEC/SEH	MANISE.JPG/JGW
MANITOWOC SW	O4408759.SWC/SWH	MANISW.JPG/JGW
MISHICOT SE	O4408751.SEC/SEH	MISHISE.JPG/JGW
TWO RIVERS NE	O4408752.NEC/NEH	TWORIVNE.JPG/JGW
TWO RIVERS NW	O4408752.NWC/NWH	TWORIVNW.JPG/JGW
TWO RIVERS SE	O4408752.SEC/SEH	TWORIVSE.JPG/JGW
TWO RIVERS SW	O4408752.SWC/SWH	TWORIVSW.JPG/JGW
TWO CREEKS SE	O4408744.SEC/SEH	TWOCRESE.JPG.JGW

*See special notes on creating ArcView/ArcINFO world files from USGS Orthophoto header files.

Registering USGS Digital Orthophoto Quadrangles (DOQs) in ArcView:

ArcView supports several image formats, including the JPEG format used by USGS DOQs. However, in order to add a DOQ as an image theme to a View, the image filename must have a suffix ArcView recognizes. DOQ filenames must be renamed to end in the .jpg suffix to be recognized in ArcView.

Once the file has a recognizable suffix, ArcView can add the DOQ to a View. However, for the image to be registered to a map projection coordinate system, either the image file must begin with some header information, or a separate "world file" of coordinate information must be provided. If neither of these things is provided, ArcView will View the image in an image coordinate system unreferenced to the surface of the earth.

DOQ image files do not begin with any header information; these data are supplied in a separate ASCII header file, 4 records long. To register DOQs, then, we must create a separate "world file". Since the image file is in the JPEG format, we must give the world file the same name followed by the extension .jgw. For example, image1.jpg has a world file named image1.jgw.

The world file is a text file consisting of 6 records:

• x-scale; dimension of a pixel in map units in x direction
• rotation term
• rotation term
• negative of y-scale; dimension of a pixel in map units in y direction
• translation term; x map coordinate of the center of the upper-left pixel
• translation term; y map coordinate of the center of the upper-left pixel

DOQs are projected into UTM coordinates in meters. Since the ground resolution of a DOQ pixel is 1 meter, the x-scale of a pixel is equal to 1. The y-scale of a pixel is also equal to one, but since images have their origin in the upper left corner, while coordinate systems have start in the lower left corner, we must take the negative of the y-scale or -1. Rotation terms for DOQs are equal to zero.

The x and y map coordinates of the upper-left pixel are located in the header file for the DOQ. These coordinates are next to last pair of real numbers at the end of record 3 of the header file. (The last pair of real numbers in record 3 are the x and y coordinates in a different datum. The metadata document DOQSTI.TXT describes the contents of the header files in complete detail.)

Using this information, the world file for a USGS DOQ looks something like this:

1

0

0

-1

439435.000000000

4865506.00000000

Once the image file has been given the appropriate suffix and a world file has been created, the image can be added to a View in ArcView. It will appear in the projection it was recorded in, registered to the parameters specified in the world file. USGS DOQs will be registered in their appropriate location in the UTM projection under the NAD83 datum.

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PART 6: REFERENCE DATA LAYERS: THE TIGER DATA

To provide context, several reference data layers of major roads, highways, and political boundaries are provided. These data were obtained from the UW-Madison's Land Information Computer Graphics Facility. There was no metadata associated with these data, so they should be used only for reference or context only. They are projected in Geographic Coordinates and appear to be in the NAD83 datum, because they match well with other data layers in the NAD83 datum. All are ArcView Shapefiles.

The following files appear in the /WRMGIS/TIGER/ folder:

Table 12: Shape Files in the TIGER Subdirectory
File/Theme Name	Description
manhwy.*	Manitowoc County highways
manhydro.*	Manitowoc County rivers and streams
manlake.*	Manitowoc County lakes
manmcd.*	Manitowoc County minor civil divisions
manroad.*	Manitowoc County roads
manseclns.*	Manitowoc County section lines

It was necessary to create additional attributes for some of the coverages.

In the attribute table for manhwy, an attribute called "name" gives the name of the highway.

In the attribute table for manmcd, an attribute called "type" is given a value of 1 = township, 2 = village, 3 = city. Another attribute called "coastal" was create and give a value of "Y" or "N" depending on whether or not the township, city, or village lies on the coast.

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PART 7: FISCHER CREEK PARK DATA

The geographic data prepared for Fischer Creek park mirror the data described in the previous sections for the overal coastal wetland project. Much of the geographic data that does not pertain to the Fischer Creek area have been removed, creating a more limited geographic data set. The 1998 WRM workshop created several additional data layers to describe the Fischer Creek areas. The WRM workshop created several ArcView shape files located in the /fischer/shape/ folder.

The WRM workshop created a digital vegetation map of Fischer Creek park using the digital orthophotos. This vegetation map contains wetland as well as upland species communities. The WRM workshop also created several ArcView point coverages that detail the location piezometers, water table recorders, trails and park boundaries.

This information may be used to plan future development of the park.

HOW TO CONTACT THE WRM PROGRAM

All correspondence should be addressed to: Water Resources Management Practicum, Institute for Environmental Studies, University of Wisconsin-Madison, Science Hall, 550 N. Park St., Madison, WI 53706. PHONE: (608) 262-2950.

Page last updated: 12/22/98