USGS
 Environmental Geochemistry and Sediment Quality in Lake Pontchartrain

Data Visualization Using Standard Desktop Geographic Mapping Tools

Chris Polloni, Laura Hayes, and E.J. McFaul

 

INTRODUCTION

This CD-ROM was developed with the intention of providing data that is compatible with Geographic Information System (GIS) tools (Polloni, 1998ab) such as Landview III (Polloni et al, 1998c), ArcExplorer (Polloni and DiGiacomo-Cohen, 1998), MapInfo and ArcView. Using latitude/longitude pairs, data from the sediment database and other sources have been used to create map layers. Each "layer" is a collection of geographic features or events such as political boundaries, a coastline, or sediment sample locations. The user can select layers (themes) with the same map projection and datum to overlay and view simultaneously. GIS tools allow spatial patterns in the data to emerge by viewing different combinations of data sets and changing the colors, symbols, or zoom level to highlight particular attributes of the data. Many of the figures contained in this publication are images saved from map windows. Offering the GIS tools and data to create custom maps, allows users to become more familiar with the data and draw their own conclusions about the environment of the Lake Pontchartrain Basin.

MAPPING TOOLS

This CD-ROM was designed to be used on a standard portable laptop so that it could be taken into the field as a research tool. The GIS mapping tools used for this project include ArcView, ARC/INFO, ArcExplorer, MapInfo, LandView, ArcView IMS, MAPGEN, GIV, and ABICAS. We have provided the GIS software ArcExplorer version 1.1 and an accompanying ArcExplorer manual, and LandView III with manuals for LandView III Help, Guided Tour, and MARPLOT, all in PDF format on this CD-ROM. To use the LandView III software the user must open the "install\windows" directory and click on "SETUP".  The Adobe Acrobat reader for viewing PDF files is also included. For the most recent version of ArcExplorer, check the ESRI website: http://www.esri.com/software/arcexplorer/

DATA  AND MAPPING PROCEDURES

Project files
A set of map project files has been assembled so that users can quickly and easily access the data that are provided. Map windows are set up within these project files in a manner that best illustrates the data contained in the GIS layers. Once the mapping tool is loaded, the user can open the appropriate project file from within that application or directly from its directory under Lpdata/.  Not all data layers are shown, as it has been left to the user to open additional themes of interest. The initial viewing scale is zoomed to the lake region for most project files and was selected to give a general overview of the basin region. Some themes (layers) consist of very dense coverages and are not turned on as they tend to dominate the display. The user may find that it is more appropriate to zoom in to an area before turning these on. Certain color schemes and symbols have been selected to be consistent with existing maps that have produced for this report. However, the user has the option of changing display parameters to highlight other trends in the data.

Individual layers
The data layers are also available individually without any pre-set legends. These can be added to existing project files or opened in a new window. An index of the GIS data included is arranged as a data matrix showing feature type, layer description, source, projection and extent of coverage. This is a simple chart to provide a minimum definition and metadata for the data layers that are included on this CD-ROM.

RESOURCE LINKS

All of the tools and data sources are available on the WWW. The following companies and government agencies have provided resources: ESRI, MapInfo, Northwood Geoscience, EPA, NOAA, CENSUS, USGS, FEMA, USCG, USACE.

REFERENCES CITED

Kenwood, Clifford, Manheim, F.T., Polloni, C.F., and Williams, S.J., 1996.  An Environmental and Geological Bibliography for Lake Pontchartrain:  U.S. Geological Survey Open-File Report 96-527, CD-ROM.

Polloni, Chris, 1998a.  Mapping Tools for CDs and the web, GRIPS'98, session chair, in session listing of the SIGCAT'98 CD/DVD Conference and EXPO, Baltimore, MD, May 17-22, 1998.

Polloni, Chris, 1998b.  HTML - XML:  An Effective Authoring tool for today's CDs, in session listing of the SIGCAT'98 CD/DVD Conference and EXPO, Baltimore, MD, May 17-22, 1998.

Polloni, Chris and DiGiacomo-Cohen, M.L., 1998.  Visualizing Long Island Sound Data Layers using Geographic Mapping Tools, in Long Island Sound Environmental Studies, Poppe, L.J. and Polloni, Chris, eds, U.S. Geological Survey Open-File Report 98-502 CD-ROM.

Polloni, C.F., Manheim, F.T., McIntire, A.G., 1998c.  Interactive Electronic Publication of Chemical-Environmental Data from Lake Pontchartrain Basin:   Exploration of Applications with LandView III, the New Interagency Database/Map Query system: Basics of the Basin Research Symposium, University of New Orleans, New Orleans, LA, May 12 and 13, 1998.

Polloni, Christopher, Tripp, B., and Truesdale, P., 1998d. An Illustrated Environmental Bibliography for Buzzards Bay, Massachusetts. U.S. Geological Survey Open-File Report 98-50 CD-ROM.

Polloni, C.F., Schmuck, E.A., Denny, J.F., Prisloe, M.P., and Babb, I.G., 1995.   Marine Geologic Atlases on CD-ROM, A Method of Assembling, Integrating and Displaying Information: Northeastern Section GSA Abstracts with Programs, Cromwell, CT, Vol. 27, no. 1, p. 74.

 

arrow2l.jpg (1149 bytes) Back to CD-ROM Development Forward to Vibracore Interactive Training arrow2r.jpg (1112 bytes)
 Select a page to view:

 

[an error occurred while processing this directive]