Robert J. Vreeland
Cartographer
USDA Natural Resources Conservation Service
National Cartography & Geospatial Center
501 W Felix, P.O. Box 6567
Fort Worth, TX 76115
Telephone (817) 334-5212 x3086
Fax (817) 334-5469
E-mail rvreelan@ftw.nrcs.usda.gov
Abstract
The National Cartography & Geospatial Center (NCG) has changed from production and manual cartography to research and development and training for digital technologies. NCG provides a wide variety of map products and services for all areas administered by the NRCS and is a focal point of modern mapping, remote sensing, and Global Positioning System (GPS) technologies. This paper highlights the changes from manual production of maps to digital cartographic solutions and data delivery.
Introduction
The National Cartography and Geospatial Center (NCG) is the mapping and spatial data center for the USDA Natural Resources Conservation Service (NRCS), formerly the Soil Conservation Service (SCS).
The concept of a centralized cartographic center was developed in 1982 when the four cartographic units located in regional offices were consolidated in Fort Worth, creating a single center. The Center's function was to produce soil survey, conservation plan, and thematic maps needed by the Agency. The focus and direction of NCG has changed from production and manual cartography to research and development and training for digital technologies. NCG provides a wide variety of map products and services for all areas administered by the NRCS and is a focal point of modern mapping, remote sensing, and Global Positioning System (GPS) technologies. In addition to these technologies, NCG is the center for natural resources inventory data collection and analysis, World Wide Web (WWW) coordination, and data archive and dissemination functions.
NCG at one time employed 55 traditional cartographers
creating maps by hand using large light tables and scribing instruments
see (Figure 1).
Figure 1.
Producing quality maps by hand required many skills and abilities: hand coordination, patience, an eye for detail, and good map reading skills see (Figure 2).
Figure 2.
Cartographers and technicians performed tasks in an assembly line organization, creating specialists with very specific map making skills. To create one map product could involve five to six people from layout and design to lithographic reproduction. Manual production involved several steps and began with the compilation of base layers from USGS quadrangles. Photo reproduction using process cameras created matte film positives, which were then used as a base for scribing different base layers on a coated film. Text was placed on a clear film that was overlaid on a film composite created from the scribe layers. Negatives and color keys completed the cartographic process up to lithographic production.
Changes in cartographic production created new challenges for the traditional cartographer. Access to computers and the Internet created a rapidly changing environment of hardware, software, and data. NCG is working on multiple computing platforms using a combination of geographic and data base software on UNIX, Windows NT, and Windows 95. To create digital thematic products, NCG is using Esri products, INFORMIX data bases, and Microsoft Office. NCG created a Thematic Mapping Model to illustrate the current cartographic processes (Figure 3).
Figure 3.
The Thematic Mapping Model is the blue print for thematic map products. The collection and distribution of data have been enhanced with the increased use of the Internet. Data sets previously unknown or unavailable can be found by conducting Internet searches. The National Spatial Data Infrastructure (NSDI) is organizing the collection and standardization of data available over the Internet. Data sets that are the proper scale and meet the endorsed Federal Geographic Data Standards (FGDC) are incorporated with data layers created by NRCS to generate a variety of thematic maps. Value added processes, such as layout design, geocoding, and automation using AML and Avenue, have greatly enhanced the quality and quantity of our thematic maps. NCG has also benefited from technological advances in printers, plotters, and imaging devices.
Technological innovations in computers and output devices have made obsolete the time consuming manual cartographic production of the past. It is no longer economically feasible for NRCS to devote large amounts of cartographic labor to a single map product. Digital cartography allows the cartographer to make multi-use digital base layers that can be used for soft and hard copy display and in a GIS for analysis. The multi-use philosophy not only applies to the creation of digital base layers, but also to almost every aspect of our digital cartographic process. The customization of ArcInfo and ArcView through the use of AML and Avenue all follow the same principle, by reusing code fragments or the automation of redundant tasks.
Showcase Projects
Status Maps
Generating status maps is a popular request of NCG. Status maps are a valuable tool allowing managers to make informed decisions. The production of status maps provides a snapshot in time of information that is quickly outdated. The combination of data base and cartographic software allows the cartographer to produce status maps rapidly after the data are updated. This provides managers with information they need in a timely fashion. The status maps of soil surveys and digital orthophotography produced by NCG are examples of this process.
Soil Survey status maps generated using ARCPLOT
NCG is maintaining two status maps for the national soil survey program: Status of Soil Surveys and Status of Soil Survey Digitizing (SSURGO). The Status of Soil Survey map is generated on an annual basis to track published soil surveys. The data base to create the map is stored and maintained at the National Soil Survey Center in Lincoln, Nebraska. The Status of Soil Survey Digitizing (SSURGO) map is generated on a biweekly basis and is used to track the soil surveys being automated to create SSURGO. The data base is maintained by the seven digitizing centers and consolidated into an EXCEL spread sheet at the NRCS state office in Madison, Wisconsin. NCG downloads both of these data bases via ftp and converts them to DBF files. The DBASEINFO command allows us to easily convert the DBF files into INFO files.
ARCPLOT and AML create a map composition depicting NRCS administrative areas. The AML is organized into routines that control the map base, thematic data, title, legend block, and source note. A menu system is used to change the parameters of each thematic characteristic. This approach allows new maps to be generated in a matter of minutes of receiving new thematic data. We are using ARCPRESS to create output files for the many different printers and plotters at NCG. However, when we need large volumes of status maps, we send postscript files to the XEROX DocuColor-40, which can produce approximately 40 copies per minute at 300 dpi. The old methodology was to send the maps to the press room for lithographic reproduction. The turn around time on the old process was four to six weeks. The same map request today can be accomplished in less than an hour.
DOQ status maps generated using ArcView
Digital orthophoto quadrangles (DOQ) mapping uses a digital coverage created of quarterquads based on the USGS 3.75-minute quadrangle. DOQ data base information is received at NCG by E-mail from United States Geological Survey (USGS). DOQ data are received as a DBF file and imported into INFO using AML�s developed at NCG. Using Database Integrator we add the INFO data to INFORMIX along with a unique key of concatenated latitude and longitude of the southeast corner of the quarterquad.
ArcView is the latest approach used by NCG to create status map products. The status of DOQ is a good example of integration between an INFORMIX data base and ArcView. By customizing ArcView with Avenue, status mapping of DOQ becomes not a process of hours, but of minutes. The push of a button can replace the active attention of the cartographer with the speed of the computer performing repeated tasks designed to meet cartographic specifications previously established.
The use of Avenue has allowed the cartographer to automate each task necessary to create the status map in ArcView. Once the INFORMIX data base is updated, the cartographer need only know the correct button on the ArcView button bar to begin the process. Avenue makes the connection to INFORMIX using Standard Query Language (SQL) and searches for the correct tables. The DOQ data available in INFORMIX are divided into three tables: quarterquads that are completed, those that are inwork, and those that are designated as water. Both the spatial base data and the tabular data base have a key, which can be joined to create the thematic layers. Each category of complete, inwork, and water is then converted to a shape file creating three smaller, easier to manage files instead of one large file.
The three newly created shape files provide a national coverage of DOQ status. Each thematic layer can be displayed to create a national status map in ArcView. Separation of DOQ into three thematic base layers provides the cartographer with the ability to reuse each layer. New maps can be created on available spatial bases at different scales. Managers can query DOQ data for a soil survey, watershed, state, or region, and get information for any number of needs. Each query can be coded in Avenue, providing the user with a friendly pushbutton user interface.
Important in creating a status map is the layout of the map. Avenue provides the cartographer with the ability to create standard layouts to meet NRCS thematic specifications. NCG has maintained a high standard of map quality through the years of manual production, and the same high quality is now expected in digital cartography. Standardized layouts have been created to provide continuity of map design for multiple sizes and different status mapping needs. The creation of standardized layouts in ArcView gives nontraditional mapmakers the ability to create maps meeting NRCS specifications without the skill and time involvement needed in traditional cartography. By creating a user-friendly system of buttons, menus, and dialogs, the program leads the user through the map making process with minimal direction and produces maps on demand.
PRISM Map Products
Delivery of precipitation maps to NRCS customers with different levels of expertise is a cartographic challenge. The PRISM (Parameter-elevation Regressions On Independent Slopes Model) is an expert system that uses point data and a digital elevation model (DEM) to generate gridded estimates of climate parameters (Daly et al., 1994). PRISM maps are created by NCG at the request of the National Water and Climate Center (WCC) in cooperation with the Oregon Climate Service (OCS) at Oregon State University. The PRISM mapping process is complex due to the ARCEDIT work required to customize the roads and streams to meet NRCS specifications. Base layers are enhanced with cities, road shields, and annotation layers. Using ARCPLOT and AML the digital base is combined with data received from OCS to create publication quality maps (Figure 4).
Figure 4.
The mapping process has evolved from generating state and county map products to a regional approach. The regional coverage can be clipped into many different geographic entities. This eliminated edge matching across state boundaries to create maps for hydrologic units. The regional approach is a multipurpose solution to serve cartographic production as well as data analysis in a GIS.
Distribution of PRISM maps and data as a digital product is a transition from the traditional production of hardcopy maps. Hardcopy maps are still the products of choice for many customers, but the inclusion of CD-ROM technology has made available new tools for the map user and GIS analyst. The production of PRISM maps has caused NCG to focus not on one aspect of delivery (hardcopy), but also on the use of CD-ROM and the Internet as necessary tools for the efficient dissemination of data. All three areas of distribution are currently used with the PRISM project. NCG is producing a hardcopy map and a CD-ROM. Data sets created using the PRISM model are available from the Oregon Climate Service on the Internet at http://www.ocs.orst.edu/prism/prism_new.html and maps in postscript format can be found at ftp://ftp.ftw.nrcs.usda.gov/pub/ams/prism/.
Map Delivery Processes
Digital cartographic output is no longer just a printed map. Technology is improving the quality of lithographic printing and driving NCG into new delivery processes, such as CD-ROM distribution and Internet mapping. Map products are now delivered in hard and soft copy, expanding the use of the map and data.
NCG uses ArcInfo and AGFA Advantra 44 Imagesetters to create positives and negatives for lithographic production. AGFA Advantra 44 imagesetters are capable of imaging data at 2400 dpi and up to 34" x 44" in size. A map composition is used in the SEPARATOR command to produce parameter files. The parameter files are edited for use on the AGFA Advantra 44 Imagesetters. Postscript files are sent to the Avantra 44 Imagesetter to create cyan, magenta, yellow, and black negatives. Negatives are used by lithographic personnel to create plates for offset printing. The time consuming process of the past where skilled laborers worked with film in several steps to create lithographic negatives has been replaced with an integrated digital approach.
CD-ROM production is used to efficiently deliver map and data products to NRCS customers. The availability of CD-ROM drives makes this technology an appealing medium. The PRISM CD-ROM developed at NCG will include data in ArcInfo format, the AMLs to produce publication quality maps, and Arc Explorer as a data browser. Arc Explorer offers users the ability to display the PRISM data on a PC platform and make simplified queries and simple printed maps.
A new approach to map dissemination is web publishing. The Internet is an ideal medium for publishing or displaying maps and related documents. Now managers in different locations can collaborate and use status maps immediately after creation. NCG is publishing on the Internet the status maps of DOQ and Soil Surveys. Access to status maps is available on the NCG home page at http://www.ftw.nrcs.usda.gov/status_data.html (figure 5).
Figure 5.
NCG is currently working towards interactive Internet mapping to complement the current static maps now available.
Conclusion
The cartographic process at NCG has seen many changes. In the past NCG produced maps by hand which required many cartographers and technicians with specialized skills. The last manual thematic map NCG produced was in March 1996
The current digital cartographic production process at NCG has room for improvement. NCG plans to implement map server technology as a better solution to the current process of creating a static map and then posting to the web. This will better serve our customers by allowing specific geographic areas of interest to be queried from the NCG digital map library.
Achieving exceptional cartographic quality is a time consuming task using our current procedures. Knowledge of AML and Avenue are necessary for cartographers at NCG to efficiently produce quality cartographic products. NCG cartographers are becoming proficient in computer use and, to some degree are programmers. Current mapping processes using computers have created an environment where one cartographer is able to follow the map process from layout and design to the prepress stage. The transition in cartography at NCG provided the tools for six cartographers and one technician to generate 456 different publication quality map products during fiscal year 1997. The graphic in Figure 6 is an example of the current cartographic production at NCG using ARCPLOT and AML.
Little Miami River Restoration Project
Clark and Greene Counties Ohio
Figure 6.
Distributing the data and the ability to create
maps on demand are changing our cartographic services. NCG will continue
to produce cost-effective solutions to mapping requests while striving
for high quality products in a timely fashion.
Acknowledgments
The authors would like to acknowledge the following people at NCG.
Dennis Darling
Mary Mathinson
Elaine Ortiz
Jim Wilson
PRISM Project
Phil Pasteris, Water and Climate Center
Greg Johnson, Water and Climate Center
George Taylor, Oregon Climate Service
Wayne Gibson, Oregon Climate Service
References
Daly, C., R.P. Neilson, and D.L. Phillips. 1994 A statistical-topographic model for mapping climatological precipitation over mountainous terrain. Journal of Applied Meterology, 33, 140-158.