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 Sanborn Map Company 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 06 encompasses whole or portions of several states including California and Nevada. Questions about the NLCD mapping zone 06 can be directed to the NLCD 2001 land cover mapping team at the USGS/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 06 are as follows:
SPRING-
Index 1 for Path 41/Row 35 on 04/08/03 = Scene_ID 7041035000309850
Index 2 for Path 41/Row 36 on 03/04/02 = Scene_ID 7041036000206350
Index 3 for Path 42/Row 33 on 04/06/00 = Scene_ID 7042033000009750
Index 3 for Path 42/Row 34 on 04/06/00 = Scene_ID 7042034000009750
Index 4 for Path 42/Row 35 on 03/27/02 = Scene_ID 7042035000208650
Index 5 for Path 43/Row 32 on 04/29/00 = Scene_ID 7043032000012050
Index 6 for Path 43/Row 33 on 05/31/00 = Scene_ID 7043033000015250
Index 7 for Path 43/Row 34 on 03/02/02 = Scene_ID 7043034000206150
Index 8 for Path 44/Row 32 on 05/12/02 = Scene_ID 7044032000213250
Index 9 for Path 44/Row 33 on 04/23/01 = Scene_ID 7044033000111350
LEAF ON (Summer)-
Index 1 for Path 41/Row 35 on 06/24/02 = Scene_ID 7041035000217550
Index 2 for Path 41/Row 36 on 06/21/01 = Scene_ID 7041036000117250
Index 8 for Path 42/Row 33 on 07/27/00 = Scene_ID 7042033000020950
Index 3 for Path 42/Row 34 on 07/27/00 = Scene_ID 7042034000020950
Index 4 for Path 42/Row 35 on 07/30/01 = Scene_ID 7042035000121150
Index 5 for Path 43/Row 32 on 07/08/02 = Scene_ID 7043032000218950
Index 6 for Path 43/Row 33 on 07/21/01 = Scene_ID 7043033000120250
Index 6 for Path 43/Row 34 on 07/21/01 = Scene_ID 7043034000120250
Index 7 for Path 44/Row 32 on 07/28/01 = Scene_ID 7044032000120950
Index 7 for Path 44/Row 33 on 07/21/01 = Scene_ID 7044033000120250
LEAF-OFF (Fall)-
Index 1 for Path 41/Row 35 on 09/20/99 = Scene_ID 7041035009926350
Index 2 for Path 41/Row 36 on 09/06/00 = Scene_ID 7041036000025050
Index 3 for Path 42/Row 33 on 09/27/99 = Scene_ID 7042033009927050
Index 4 for Path 42/Row 34 on 10/18/01 = Scene_ID 7042034000129150
Index 4 for Path 42/Row 35 on 10/18/01 = Scene_ID 7042035000129150
Index 5 for Path 43/Row 32 on 10/20/99 = Scene_ID 7043032009929350
Index 6 for Path 43/Row 33 on 10/06/00 = Scene_ID 7043033000028050
Index 7 for Path 43/Row 34 on 10/22/00 = Scene_ID 7043034000029650
Index 8 for Path 44/Row 32 on 10/19/02 = Scene_ID 7044032000229250
Index 9 for Path 44/Row 33 on 10/13/00 = Scene_ID 7044033000028750
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)