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Introduction

The Coastal Change Analysis Project Chesapeake Bay Region CD-ROM shows changes in land cover for the Chesapeake Bay region over the 5-year interval from 1984 to 1988-89. It is the result of a multiyear effort that has focused on the Chesapeake Bay as a prototype for the Coastal Change Analysis Project (CCAP) of the NOAA Coastal Ocean Program's Estuarine Habitat Studies Program. The Chesapeake Bay data set constitutes one of the largest change detection efforts ever attempted, covering an area of approximately 30,000 square miles with a source data resolution of 30 meters by 30 meters. Its greatest value is in its synoptic coverage and consistent classification over such a large area.

This effort emphasizes a geographic approach including the use of geographic information systems, the Landsat Thematic Mapper (see sample scene), other satellite sensors, and aerial photographs. CCAP has served as a catalyst for cooperative development among many separate government agencies involved in wetlands management and land cover analysis. These include the National Wetlands Inventory (NWI) of the U. S. Fish and Wildlife Service, the Environmental Monitoring and Assessment Program (EMAP) of the Environmental Protection Agency (EPA), and the National Mapping Division of the U. S. Geological Survey (USGS). The CD-ROM was produced cooperatively by the NOAA National Marine Fisheries Service, National Geophysical Data Center, and National Oceanographic Data Center.

CD-ROM Contents

1. The Chesapeake Bay Land Classification Data Set is based on an analysis of Landsat Thematic Mapper (TM) scenes of the Chesapeake Bay area (Table 1).

   Table 1. Landsat TM scenes processed

   PATH	ROW	DATES
   14	33	09-21-1984	11-03-1988
   14	34	09-21-1984	11-03-1988
   15	33	08-27-1984	10-12-1989
   15	34	08-27-1984	10-12-1989

2. This CD-ROM data product consists of three data sets:
   1. Analysis of four Landsat Thematic Mapper scenes from 1984,
   2. Analysis of four Landsat Thematic Mapper scenes from 1988-89 for the same area, and
   3. Analysis of the resulting change between 1984 and 1988-89.

3. The land cover analyses distinguish 14 land cover classes:
   (1) developed-high intensity, (2) developed-low intensity, (3)cropland, (4) grassland, (5) deciduous forest, (6) evergreen forest, (7) mixed forest, (8) mixed shrub/scrub, (9) palustrine forest, (10) estuarine emergent wetland, (11) palustrine emergent wetland, (12) tidal flats, (13) exposed land (bare soil + sand), (14) water. The change analysis resulted in 81 classes.

4. Data Characteristics
   The data are in a binary unblocked format. A record equals one row of pixels, and the first data record value is in the upper left-hand corner of the image.

   The positional accuracy and precision of this data set are based on the Landsat Thematic Mapper database. Nominally the source data are 30 meter by 30 meter cells with a positional accuracy of 0.5 cell (15 m) in each direction. Additional uncertainties, however, reduce the spatial precision of this data set to about 1.5 cells (45 m) in each direction. This, in turn, yields a minimum detection unit of 3 cells by 3 cells (90 m by 90 m) or about 2.5 acres.

   Tests indicate that overall confidence in the satellite derived maps is warranted as high as for aerial photograph/field maps provided the spatial resolution is 2.5 acres or greater. Tests for logical consistency indicate that all row and column positions in the selected latitude/longitude window contain data. Conversion and integration with vector files indicate that all positions are consistent with earth coordinates covering the same area. The classification scheme comprehensively includes all anticipated land covers, and all pixels have been classified.

5. Data Access/Display Software
   This CD-ROM includes GeoVu display software developed by the National Geophysical Data Center (NGDC). Some features of this software include enabling the user to select and view a specific data set, browse the data documentation, identify the geographic area of interest, and view the land-cover classification codes. Users may display images using prepackaged pallettes or develop their own. Data may be displayed on the screen, saved to disk, or downloaded to floppy diskette.

Minimum System Requirements

This software will operate on any IBM-PC/AT or compatible personal computer, with MS Windows (Version 3.1) and a compatible CD-ROM reader. The software is not currently designed to operate on other types of computers (e.g., Macintosh). However, support for other platforms is expected in the future. A minimum of 3 MB of hard disk space are required to load and execute the software.

A large capacity hard disk is needed if large files are to be saved. A minimum of 8 MB of RAM is recommended, and a math co-processor may significantly speed up the operation.

How to Order:

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All customers may order online using Visa, MasterCard, American Express, or Discover. Credit card orders are also accepted via telephone, fax, or e-mail at the National Oceanographic Data Center:

E-mail: NODC.Services@noaa.gov
Telephone: 301-713-3277
Fax: 301-713-3302

Customers wishing to purchase these products using a check or money order must mail their order to:
NOAA National Data Centers
Attn: Fiscal Group
151 Patton Avenue
Asheville, NC 28801