Homer, C., C. Huang, L. Yang, B. Wylie and M. Coan, 2004. Development of a 2001 national land cover database for the United States. Photogrammetric Engineering and Remote Sensing.
The USGS acknowledges the support of Space Imaging in development of data in this zone.
The NLCD 2001 was created by partitioning the U.S. into mapping zones. A total of 66 mapping zones were delineated within the conterminous U.S. based on ecoregion and geographical characteristics, edge matching features and the size requirement of Landsat mosaics. Mapping zone 02 encompasses western portion of Oregon. Questions about the NLCD mapping zone 02 can be directed to the NLCD 2001 land cover mapping team at the National Center, EROS, Sioux Falls, SD (605) 594-6151 or mrlc@usgs.gov.
By combining the training data with Landsat spectral data and other ancillary data, percent imperviousness prediction models were developed using a regression tree algorithm (named "Cubist"). All data layers used as input for running the Cubist in order to establish the prediction model for imperviousness are listed in the "Supplemental Information" section. Three ancillary data sets were used for urban/suburban delineation masking, which is essential to confine the imperviousness mapping within the developed areas.
After the best combination of possible input data layers had been determined and the final percent impervious layer produced, the urban mask created was used to eliminate those pixels from the final percent impervious file that fall outside identified impervious surface areas. Thus, the impervious pixels identified within the mask were retained, while all non-impervious surface pixels were removed from the final product. This corrected for any small areas of pixels that may have been included as part of the impervious surface layer because their spectral signature was not covered in the Cubist modeling process. Finally, visual inspection of imperviousness layer was made with limited manual editing to eliminate non-urban areas based on area of interest delineated by the mapping team.
Acquisition dates of Landsat ETM+ (TM) scenes used for land cover classification in zone 02 are as follows:
SPRING-
Index 5 for Path 46/Row 28 on 04/10/00 = Scene_ID 5046028000010110
Index 6 for Path 46/Row 29 on 03/20/01 = Scene_ID 7046029000107950
Index 2 for Path 46/Row 30 on 05/07/01 = Scene_ID 7046030000112750
Index 3 for Path 47/Row 28 on 02/26/02 = Scene_ID 7047028000205750
Index 3 for Path 47/Row 29 on 02/26/02 = Scene_ID 7047029000205750
LEAF ON (Summer)-
Index 3 for Path 46/Row 28 on 08/27/01 = Scene_ID 7046028000123950
Index 4 for Path 46/Row 29 on 08/08/00 = Scene_ID 7046029000022150
Index 1 for Path 46/Row 30 on 07/26/01 = Scene_ID 7046030000120750
Index 2 for Path 47/Row 28 on 07/01/01 = Scene_ID 7047028000118250
Index 2 for Path 47/Row 29 on 07/01/01 = Scene_ID 7047029000118250
LEAF-OFF (Fall)-
Index 3 for Path 46/Row 28 on 09/25/00 = Scene_ID 7046028000026950
Index 2 for Path 46/Row 29 on 09/28/01 = Scene_ID 7046029000127150
Index 5 for Path 46/Row 30 on 08/27/01 = Scene_ID 7046030000123950
Index 1 for Path 47/Row 28 on 10/16/99 = Scene_ID 7047028009928950
Index 1 for Path 47/Row 29 on 10/16/99 = Scene_ID 7047029009928950
Landsat data and ancillary data used for the imperviousness prediction -
Data Type of DEM composed of 1 band and a Continuous Variable Type.
Data Type of Slope composed of 1 band and a Continuous Variable Type.
Data Type of Aspect composed of 1 band of Categorical Variable Type.
Data type of Position Index composed of 1 band of Continuous Variable Type.
Ancillary data used for urban area masking include:
1. NOAA Defense Meteorological Satellite Program 1 km city light data (1 band)
2. MRLC 1992 classification (1 band)
3. TIGER 2000 roads (1 band)
4. Oregon City Limits data (1 band)
5. Oregon Urban Growth Boundary (1 band)