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 NARSAL 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 48 encompasses whole or portions of several states including Alabama, Georgia and Tennessee. Questions about the NLCD mapping zone 48 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 48 are as follows:
SPRING-
Index 1 for Path 19/Row 35 on 03/10/02 = Scene_ID 7019035000206950
Index 2 for Path 19/Row 36 on 03/07/01 = Scene_ID 7019036000106650
Index 3 for Path 20/Row 35 on 02/26/01 = Scene_ID 7020035000105750
Index 3 for Path 20/Row 36 on 02/26/01 = Scene_ID 7020036000105750
Index 4 for Path 20/Row 37 on 12/27/01 = Scene_ID 7020037000136150
Index 5 for Path 21/Row 35 on 02/28/02 = Scene_ID 5021035000205910
Index 6 for Path 21/Row 36 on 03/05/01 = Scene_ID 7021036000106450
Index 7 for Path 21/Row 37 on 02/15/00 = Scene_ID 7021037000004650
LEAF ON (Summer)-
Index 1 for Path 19/Row 35 on 06/08/00 = Scene_ID 7019035000016050
Index 2 for Path 19/Row 36 on 05/31/00 = Scene_ID 5019036000015210
Index 3 for Path 20/Row 35 on 06/18/01 = Scene_ID 7020035000116950
Index 3 for Path 20/Row 36 on 06/18/01 = Scene_ID 7020036000116950
Index 4 for Path 20/Row 37 on 05/14/00 = Scene_ID 7020037000013550
Index 5 for Path 21/Row 35 on 06/23/03 = Scene_ID 5021035000317410
Index 6 for Path 21/Row 36 on 07/30/99 = Scene_ID 5021036009921110
Index 5 for Path 21/Row 35 on 06/23/03 = Scene_ID 5021035000317410
LEAF-OFF (Fall)-
Index 1 for Path 19/Row 35 on 10/25/01 = Scene_ID 5019035000129810
Index 1 for Path 19/Row 36 on 10/25/01 = Scene_ID 5019036000129810
Index 2 for Path 20/Row 35 on 11/09/01 = Scene_ID 7020035000131350
Index 2 for Path 20/Row 36 on 11/09/01 = Scene_ID 7020036000131350
Index 2 for Path 20/Row 37 on 11/09/01 = Scene_ID 7020037000131350
Index 3 for Path 21/Row 35 on 10/31/01 = Scene_ID 7021035000130450
Index 3 for Path 21/Row 36 on 10/31/01 = Scene_ID 7021036000130450
Index 3 for Path 21/Row 37 on 10/31/01 = Scene_ID 7021037000130450
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)