USGS - Pontchartrain Geochemistry

Lake Pontchartrain Basin: Bottom Sediments and Related Environmental Resources

GIS Layers and Metadata

Back to Data Visualization
for pre-made project files and more info

The matrix below lists individual GIS layers that were used in many of the figures in the sediment database section. They were generated as .tab files in MapInfo and then exported to MapInfo Interchange Format (.mif and .mid) and converted to ArcView shapefiles (.shp). Each layer is a downloadable .zip archive. The MapInfo archives contain a .mif (graphic data) and a .mid (tabular data). The ArcView archives contain a .shp, .dbf, and .shx, or in the case of the raster images, a .tif and a .tfw (tif world file for registering the image). [Note: The MapInfo .zip files have the same archival name as the ArcView .zip files, so if you are downloading both, you will want to create two separate directories on your hard drive.]

Also listed in this table is metadata describing the feature types included in each layer (point, line, polygon, or raster), a verbal description of the layer's content, the source from which the data was obtained or generated, the projection in which the data is stored, and the approximate bounding coordinates of the layer.

Lead, zinc, and sand_pct are examples of data extracted from the sediment database for analysis. They were exported from Access queries and then mapped in a GIS. For future publications, additional layers such as these will be created and inspected for patterns of sediment contamination. Some layers (for example, lakes, land, urban, graticul, the DEMs) are provided as a backdrops or geographic references for the sediment data. Other layers may be more valuable once they are further processed. For example, a point file of bathymetric soundings from Lake Borgne has been included for its raw data, but once gridded and contoured, it would provide a more illustrative map of the lake bottom.

Zip files containing all the available layers are offered here:
MapInfo tables	ArcView shapefiles and tifs

Individual layers:

MAPINFO FILES	ARCVIEW FILES	FEATURE TYPE	DESCRIPTION	SOURCE	PROJECTION	APPROX. BOUNDS E-W	APPROX. BOUNDS S-N
Maurbath.zip	Maurbath.zip	Point	Lake Maurepas bathymetry (soundings in meters and feet)	Digitized from NOAA navigation chart 11369	Geographic (Lat/Long)	90.38W to 90.6W	30.16N to 30.35N
Maurcont.zip	Maurcont.zip	Line	Contoured bathymetry for Lake Maurepas (m and ft)	Contoured Maurepas bathymetry using Vertical Mapper	Geographic (Lat/Long)	90.38W to 90.6W	30.16N to 30.35N
Maurshor.zip	Maurshor.zip	Line	Shoreline of Lake Maurepas	Used lat/longs for Lake Maurepas shoreline from lakes.mif	Geographic (Lat/Long)	90.3W to 90.6W	30.16N to 30.35N
Pontbath.zip	Pontbath.zip	Point	Lake Pontchartrain bathymetry (soundings in meters)	Digitized from NOAA navigation chart 11369	Geographic (Lat/Long)	89.73W to 90.44W	30.0N to 30.4N
Pontcont.zip	Pontcont.zip	Line	Contoured bathymetry for Lake Pontchartrain (m and ft)	Contoured Pontchartrain bathymetry using Vertical Mapper	Geographic (Lat/Long)	89.73W to 90.43W	30.0N to 30.4N
Pontshor.zip	Pontshor.zip	Line	Shoreline of Lake Pontchartrain	Used MapInfo's autotrace function on Lake Pontchartrain in "lakes.tab"	Geographic (Lat/Long)	89.62W to 90.44W	30.0N to 30.4N
Borgbath.zip	Borgbath.zip	Point	Lake Borgne bathymetry (soundings in meters)	NOAA's Geophysical Data System for Hydrographic Survey Data (CD-ROM data set) v 3.3	Geographic (Lat/Long)	89.42W to 89.86W	29.85N to 30.25N
Stations.zip	Stations.zip	Point	Station locations in pont_db database	USGS pont_db.mdb (this volume)	Geographic (Lat/Long)	88.5W to 92.9W	29.0N to 30.0N
Sand.zip	Sand.zip	Point	Sample locations showing sand percent	Extracted from USGS pont_db.mdb (this volume)	Geographic (Lat/Long)	88.51W to 92.87W	29.02N to 30.42
Lead.zip	Lead.zip	Point	Lead concentrations	Extracted from USGS pont_db.mdb (this volume)	Geographic (Lat/Long)	88.51W to 92.87W	29.02N to 30.42
Zinc.zip	Zinc.zip	Point	Zinc concentrations	Extracted from USGS pont_db.mdb (this volume)	Geographic (Lat/Long)	88.51W to 92.87W	29.02N to 30.42
Land.zip	Land.zip	Polygon	Land around Lakes Maurepas, Pontchartrain, and Borgne	Created outer polygon from NOAA's Gc80_04	Geographic (Lat/Long)	89.47W to 90.65W	29.84N to 30.5N
Lakes.zip	Lakes.zip	Polygon	Maurepas, Pontchartrain, Borgne, Mississippi River	Created inner polygons from NOAA's Gc80_04	Geographic (Lat/Long)	89.3W to 90.67W	29.8N to 30.4N
Urban.zip	Urban.zip	Polygon	Urban area of New Orleans and Kenner	Digitized from NOAA navigation chart 11369	Geographic (Lat/Long)	89.9W to 90.3W	29.9N to 30.1N
Cause_bt.zip	Cause_bt.zip	Line/polygon	Causeway and Bayou Trepagnier	Digitized from NOAA navigation chart 11369	Geographic (Lat/Long)	90.09W to 90.4W	30.0N to 30.37N
La_bound.zip	La_bound.zip	Line	State border of Louisiana	LandView point file converted to line using MapInfo	Geographic (Lat/Long)	88.8W to 94.1W	28.9N to 33.1N
Gc80_02.zip	Gc80_02.zip	Line	Gulf of Mexico coastline (southwestern Louisiana)	NOAA's medium resolution digital vector shoreline http://seaserver.nos.noaa.gov/projects/shoreline/shoreline.html	Geographic (Lat/Long)	91.07W to 93.45W	29.39N to 31.05N
Gc80_03.zip	Gc80_03.zip	Line	Gulf of Mexico coastline (south-central Louisiana)	NOAA's medium resolution digital vector shoreline http://seaserver.nos.noaa.gov/projects/shoreline/shoreline.html	Geographic (Lat/Long)	89.95W to 91.38W	29.04N to 29.98N
Gc80_04.zip	Gc80_04.zip	Line	Gulf of Mexico coastline (southeastern Louisiana)	NOAA's medium resolution digital vector shoreline http://seaserver.nos.noaa.gov/projects/shoreline/shoreline.html	Geographic (Lat/Long)	88.81W to 91.27W	28.92N to 30.48N
Area_cd.zip	Area_cd.zip	Line/polygon	Subdivision of southeastern Louisiana estuarine areas by letter codes used as a general area indicator	Digitized on screen using other GIS layers as a guide; note that the areas along the shore extend inshore a bit to ensure that all sample locations were captured	Geographic (Lat/Long)	89.17W to 90.61	29.37N to 30.39N
Squares.zip	Squares.zip	Polygon	Numerical grid covering Lakes Maurepas, Pontchartrain, and Borgne; designed for systematic comparison of sediment parameters by location	Generated with MapInfo's GridMaker	Geographic (Lat/Long)	89.36W to 90.61W	29.81N to 30.42N
Graticul.zip	Graticul.zip	Line	Graticule at 0.1 degree covering Lakes Maurepas, Pontchartrain, and Borgne	Generated with MapInfo's GridMaker	Geographic (Lat/Long)	89.47W to 90.65W	29.84N to 30.5N
Batr_dem.zip	Batr_dem.zip	Raster	Digital Elevation Model of Baton Rouge area	1:250,000-scale USGS DEM downloaded from http://edcwww.cr.usgs.gov/glis/hyper/guide/1_dgr_dem	Geographic (Lat/Long)	90.0W to 91.0W	30.0N to 31.0N
Newo_dem.zip	Newo_dem.zip	Raster	Digital Elevation Model of New Orleans area	1:250,000-scale USGS DEM downloaded from http://edcwww.cr.usgs.gov/glis/hyper/guide/1_dgr_dem	Geographic (Lat/Long)	90.0W to 91.0W	29.0N to 30.0N
Mobl_dem.zip	Mobl_dem.zip	Raster	Digital Elevation Model of Mobile area	1:250,000-scale USGS DEM downloaded from http://edcwww.cr.usgs.gov/glis/hyper/guide/1_dgr_dem	Geographic (Lat/Long)	89.0W to 90.0W	30.0N to 31.0N
Bret_dem.zip	Bret_dem.zip	Raster	Digital Elevation Model of Breton Sound area	1:250,000-scale USGS DEM downloaded from http://edcwww.cr.usgs.gov/glis/hyper/guide/1_dgr_dem	Geographic (Lat/Long)	89.0W to 90.0W	29.0N to 30.0N