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 33 encompasses whole or portions of several states including Colorado, Kansas, Nebraska, and Wyoming. Questions about the NLCD mapping zone 33 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 33 are as follows:
SPRING-
Index 6 for Path 30/Row 32 on 05/04/00 = Scene_ID 7030032000012550
Index 6 for Path 30/Row 33 on 05/04/00 = Scene_ID 7030033000012550
Index 6 for Path 30/Row 34 on 05/04/00 = Scene_ID 7030034000012550
Index 3 for Path 31/Row 31 on 04/28/01 = Scene_ID 7031031000111850
Index 1 for Path 31/Row 32 on 04/09/00 = Scene_ID 7031032000010050
Index 1 for Path 31/Row 33 on 04/09/00 = Scene_ID 7031033000010050
Index 2 for Path 31/Row 34 on 05/11/00 = Scene_ID 7031034000013250
Index 4 for Path 32/Row 31 on 05/02/00 = Scene_ID 7032031000012350
Index 4 for Path 32/Row 32 on 05/02/00 = Scene_ID 7032032000012350
Index 5 for Path 32/Row 33 on 04/16/00 = Scene_ID 7032033000010750
Index 7 for Path 33/Row 31 on 04/13/02 = Scene_ID 7033031000210350
Index 8 for Path 33/Row 32 on 05/12/01 = Scene_ID 7033032000113250
Index 9 for Path 33/Row 33 on 03/28/02 = Scene_ID 7033033000208750
Index10 for Path 34/Row 31 on 04/04/02 = Scene_ID 7034031000209450
Index11 for Path 34/Row 32 on 06/01/00 = Scene_ID 7034032000015350
LEAF ON (Summer)-
Index 1 for Path 30/Row 32 on 07/07/00 = Scene_ID 7030032000018950
Index 1 for Path 30/Row 33 on 07/07/00 = Scene_ID 7030033000018950
Index 1 for Path 30/Row 34 on 07/07/00 = Scene_ID 7030034000018950
Index 2 for Path 31/Row 31 on 07/14/00 = Scene_ID 7031031000019650
Index 2 for Path 31/Row 32 on 07/14/00 = Scene_ID 7031032000019650
Index 2 for Path 31/Row 33 on 07/14/00 = Scene_ID 7031033000019650
Index 3 for Path 31/Row 34 on 06/15/01 = Scene_ID 7031034000116650
Index 8 for Path 32/Row 31 on 08/06/00 = Scene_ID 7032031000021950
Index 8 for Path 32/Row 32 on 08/06/00 = Scene_ID 7032032000021950
Index 9 for Path 32/Row 33 on 06/06/01 = Scene_ID 7032033000115750
Index 4 for Path 33/Row 31 on 07/28/00 = Scene_ID 7033031000021050
Index 4 for Path 33/Row 32 on 07/28/00 = Scene_ID 7033032000021050
Index 5 for Path 33/Row 33 on 08/13/00 = Scene_ID 7033033000022650
Index 7 for Path 34/Row 31 on 07/09/02 = Scene_ID 7034031000219050
Index 6 for Path 34/Row 32 on 06/23/02 = Scene_ID 7034032000217450
LEAF-OFF (Fall)-
Index 3 for Path 30/Row 32 on 09/12/01 = Scene_ID 7030032000125550
Index 2 for Path 30/Row 33 on 09/25/00 = Scene_ID 7030033000026950
Index 2 for Path 30/Row 34 on 09/25/00 = Scene_ID 7030034000026950
Index 1 for Path 31/Row 31 on 10/18/00 = Scene_ID 7031031000029250
Index 1 for Path 31/Row 32 on 10/18/00 = Scene_ID 7031032000029250
Index 1 for Path 31/Row 33 on 10/18/00 = Scene_ID 7031033000029250
Index 1 for Path 31/Row 34 on 10/18/00 = Scene_ID 7031034000029250
Index 5 for Path 32/Row 31 on 09/10/01 = Scene_ID 7032031000125350
Index 4 for Path 32/Row 32 on 10/09/00 = Scene_ID 7032032000028350
Index 4 for Path 32/Row 33 on 10/09/00 = Scene_ID 7032033000028350
Index 6 for Path 33/Row 31 on 10/16/00 = Scene_ID 7033031000029050
Index 6 for Path 33/Row 32 on 10/16/00 = Scene_ID 7033032000029050
Index 6 for Path 33/Row 33 on 10/16/00 = Scene_ID 7033033000029050
Index 7 for Path 34/Row 31 on 10/13/02 = Scene_ID 7034031000228650
Index 8 for Path 34/Row 32 on 11/06/99 = Scene_ID 7034032009931050
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)