Source: https://maps.indiana.edu/metadata/Environment/Land_Cover_Impervious_Surfaces_2011.html
Timestamp: 2019-04-20 12:43:48+00:00

Document:
(1) Homer, C.G., Dewitz, J.A., Yang, L., Jin, S., Danielson, P., Xian, G., Coulston, J., Herold, N.D., Wickham, J.D., and Megown, K., 2015, Completion of the 2011 National Land Cover Database for the conterminous United States-Representing a decade of land cover change information: Photogrammetric Engineering and Remote Sensing, v. 81, no. 5, p. 345-354.
(2) Jin, S., Yang, L., Danielson, P., Homer, C., Fry, J., and Xian, G., 2013, A comprehensive change detection method for updating the National Land Cover Database to circa 2011. Remote Sensing of Environment, v. 132, p. 159–175.
(3) Xian, G., Homer, C., Dewitz, J., Fry, J., Hossain, N., and Wickham, J., 2011, The change of impervious surface area between 2001 and 2006 in the conterminous United States: Photogrammetric Engineering and Remote Sensing, v. 77, no. 8, p. 758-762.
(4) Coulston, J. W., Moisen, G. G., Wilson, B. T., Finco, M. V., Cohen, W. B., and Brewer, C. K., 2012, Modeling percent tree canopy cover -- a pilot study: Photogrammetric Engineering and Remote Sensing, v. 78, no. 7, p. 715-727.
The USGS acknowledges the support of USGS and contractor NLCD 2011 Land Cover Mapping Teams in development of data for this map.
IMPERVIOUS_SURFACE_2011_USGS_IN is a grid (30-meter cell size) showing estimated percentages of impervious surfaces in Indiana in 2011.This grid is a subset of the National Land Cover Database (NLCD 2011) suite of data products. The attributes are percentage values of estimated impervious-surface cover within each 30-meter grid cell, or pixel.
"The National Land Cover Database products are created through a cooperative project conducted by the Multi-Resolution Land Characteristics (MRLC) Consortium. The MRLC Consortium is a partnership of Federal agencies (www.mrlc.gov), consisting of the U.S. Geological Survey (USGS), the National Oceanic and Atmospheric Administration (NOAA), the U.S. Environmental Protection Agency (EPA), the U.S. Department of Agriculture - Forest Service (USDA-FS), the National Park Service (NPS), the U.S. Fish and Wildlife Service (USFWS), the Bureau of Land Management (BLM) and the USDA Natural Resources Conservation Service (NRCS). The success of NLCD over nearly two decades is credited to the continuing collaborative spirit of the agencies that make up the MRLC. NLCD 2011 is the most up-to-date iteration of the National Land Cover Database, the definitive Landsat-based, 30-meter resolution land cover database for the Nation. The data in NLCD 2011 are completely integrated with NLCD 2001 (2011 Edition, amended 2014) and NLCD 2006 (2011 Edition, amended 2014).
For NLCD 2011, there are 5 primary data products: 1) NLCD 2011 Land Cover 2) NLCD 2006/2011 Land Cover Change Pixels labeled with the 2011 land cover class 3) NLCD 2011 Percent Developed Imperviousness 4) NLCD 2006/2011 Percent Developed Imperviousness Change Pixels 5) NLCD 2011 Tree Canopy Cover provided by an MRLC partner - the USDA Forest Service Remote Sensing Applications Center.
In addition, ancillary metadata includes the NLCD 2011 Path/Row Index shapefile showing the footprint of Landsat scenes and change analysis pairs used to derive 2006/2011 spectral change. All Landsat scene acquisition dates are included in the shapefile's attribute table. As part of the NLCD 2011 project, NLCD 2001 and 2006 land cover and impervious data products were revised and reissued (2011 Edition, amended 2014) to provide full compatibility with the new NLCD 2011 products. The 2014 amended version corrects for the over-elimination of small areas of the four developed classes.
NLCD Tree Canopy Cover was created using MRLC mapping zones from NLCD 2001 (see Tree Canopy Cover metadata for additional detail). All other NLCD 2011 products were created on a path/row basis and mosaicked to create a seamless national product. Questions about the NLCD 2011 land cover product can be directed to the NLCD 2011 land cover mapping team at the USGS/EROS, Sioux Falls, SD (605) 594-6151 or mrlc@usgs.gov."
IMPERVIOUS_SURFACE_2011_USGS_IN is the Indiana subset of the impervious-surface land-cover pixels (2011), a derivative product of the National Land Cover Database (NLCD 2011).
This file is available to anyone, but access may be contingent on written request, specific terms relevant to the agency or person making the request and/or current freedom of information statutes in the state of Indiana.
DATA DISCLAIMER This data set was compiled by Indiana University, Indiana Geological Survey, using data believed to be accurate; however, a degree of error is inherent in all data. This product is distributed "AS-IS" without warranties of any kind, either expressed or implied, including but not limited to warranties of suitability to a particular purpose or use. No attempt has been made in either the design or production of these data to define the limits or jurisdiction of any federal, state, or local government. These data are intended for use only at the published scale or smaller and are for reference purposes only. They are not to be construed as a legal document or survey instrument. A detailed on-the-ground survey and historical analysis of a single site may differ from these data.
LIMITATION OF WARRANTIES AND LIABILITY This product is provided "AS IS", without any other warranties or conditions, expressed or implied, including, but not limited to, warranties for product quality, or suitability to a particular purpose or use. The risk or liability resulting from the use of this product is assumed by the user. Indiana University, Indiana Geological Survey shares no liability with product users indirect, incidental, special, or consequential damages whatsoever, including, but not limited to, loss of revenue or profit, lost or damaged data or other commercial or economic loss. Indiana University, Indiana Geological Survey is not responsible for claims by a third party. The maximum aggregate liability to the original purchaser shall not exceed the amount paid by you for the product.
"A formal accuracy assessment has not been conducted for NLCD 2011 Land Cover."
"This document and the described landcover map are considered "provisional" until a formal accuracy assessment is completed. The U.S. Geological Survey can make no guarantee as to the accuracy or completeness of this information, and it is provided with the understanding that it is not guaranteed to be correct or complete. Conclusions drawn from this information are the responsibility of the user."
The following is excerpted from metadata provided by the USGS for the NLCD 2011: "The NLCD 2011 final seamless products include: 1) NLCD 2011 Land Cover; 2) NLCD 2011 Percent Developed Imperviousness; 3) NLCD 2006/2011 Change Pixels labeled with the 2011 land cover class; 4) NLCD 2006/2011 Percent Developed Imperviousness Change; and 5)NLCD 2011 Tree Canopy Cover."
Completeness_Report: This NLCD product is the version dated October 10, 2014.
"Landsat image selection and preprocessing: For NLCD 2011 change analysis, two 2-date pairs of Landsat scenes were selected for each path/row to represent ground conditions in circa 2006 and 2011. One additional circa 2011 scene was selected to enhance modeling results for land cover labeling. In selecting the 5 scenes, the temporal range of the imagery was restricted to reduce the impact of seasonal and phenological variation. A pre-processing step was performed to convert the digital number to top of atmosphere reflectance using procedures similar to those established for the NLCD 2001 mapping effort (Homer et al., 2004). Reflectance derivatives, including a tasseled-cap transformation and a 3-ratio index, were generated for each scene to use in the modeling process as independent variables. Where present, clouds and cloud shadows were digitized and masked.
NLCD 2011 Percent Developed Imperviousness and Percent Developed Imperviousness Change Analysis: Because the four NLCD developed classes are derived from a percent imperviousness mapping product, an overview of steps required to update the NLCD 2001 imperviousness to reflect urban growth captured in 2006 era Landsat imagery is provided here (Xian et al., 2010). These same procedures were employed to produce NLCD 2011 Percent Developed Imperviousness and 2006-2011 Percent Developed Imperviousness Change. First, 2009 nighttime lights imagery from the NOAA Defense Meteorological Satellite Program (DMSP) was imposed on the NLCD 2006 impervious surface product to exclude low density imperviousness outside urban and suburban centers so that only imperviousness in urban core areas would be used in the training dataset. Two training datasets, one having a relatively larger urban extent and one having a smaller extent, were produced through imposing two different thresholds on city light imagery. Second, each of the two training datasets combined with 2006 Landsat imagery was separately applied using a regression tree (RT) algorithm to build up RT models. Two sets of RT models were then used to estimate percent imperviousness and to produce two 2006 synthetic impervious surfaces. Similarly, the same two training datasets were used with 2011 Landsat imagery to create two sets of RT models that produce two 2011 synthetic impervious surfaces.
Third, the 2006 and 2011 synthetic impervious surface pairs were compared using both 2006 impervious surface products to retain 2006 impervious surface area (ISA) in the unchanged areas. The 2009 DMSP nighttime lights imagery was then employed to ensure that non-imperviousness areas were not included and that new impervious surfaces emerged in the city light extent. After this step, two 2011 intermediate impervious surfaces were produced. Finally, the two intermediate products and 2006 imperviousness were compared to remove false estimates in non-urban areas and generate a 2011 impervious surface estimate. Imperviousness threshold values used to derive the NLCD developed classes are: (Class 21) developed open space (imperviousness < 20%), (Class 22) low-intensity developed (imperviousness from 20 - 49%), (Class 23) medium intensity developed (imperviousness from 50 -79%), and (Class 24) high-intensity developed (imperviousness > 79%).
To improve NLCD imperviousness the 2011 project included a process to reduce omission and commission error in NLCD 2001, 2006, and 2011 products. This activity was completed for urban areas in most of the eastern ½ of the conterminous United States. High resolution (one-meter ground sample distance) National Aerial Imagery Program (NAIP - http//fsa.usda.gov/FSA/) imagery was used to verify imperviousness. Using hand-edits, imperviousness was removed from areas incorrectly identified as developed and added to areas where developed land cover was missed. A modeling process was implemented to add missed imperviousness changes to the correct era and to fill areas where developed was removed with an appropriate non-developed land cover class. These improvements were incorporated with the derived developed classes in all areas of imperviousness and land cover versions released with NLCD 2011 editions. Revised products, NLCD 2001 and NLCD 2006 Impervious (2011 Editions) and NLCD 2001-2006 Impervious Change Pixels (2011 Edition) are included as part of the NLCD 2011 product release.
NLCD 2011 Land Cover (Final Product): Additional processing steps were implemented to create the final NLCD 2011 land cover map. Individual path/row change pixel results were assembled to form an intermediate seamless national product. This seamless change pixel map was reviewed and edited to remove regional inconsistencies. Refined NLCD 2011 change pixels were then combined with the re-issued NLCD 2006 Land Cover Version (2011 Edition), and the resulting image was smart-eliminated to a 5-pixel mmu. This final step eliminated single pixels and patches less than 5 pixels in extent that appeared as a result of combining the separate images.
NLCD 2011 (amended 2014): The release in 2014 of amended versions of land cover for 2001, 2006, and 2011 was made to correct for unintended differences between the impervious dataset and the four land cover developed classes (Open Space, Low Intensity, Medium Intensity, and High Intensity). NLCD developed classes are tied directly to the impervious product values. However, the land cover product Minimum Mapping Unit (MMU) is five pixels whereas the impervious product MMU is single pixel. This MMU difference creates problems when the impervious single pixel MMU product is directly crosswalked into the 5-pixel MMU land cover developed classes. The smoothing process, which generalizes the land cover product to a 5-pixel MMU, can create small areas which are no longer directly represented in the imperviousness product because they are artifacts of the smoothing. Since these changes are not real and not present in the impervious layer, the new version removes these artifacts and re-establishes the direct linkage between the imperviousness and land cover products for any developed area. Combined developed areas (all developed classes combined into a group) in the land cover product must still meet the 5-pixel MMU threshold; however, the four NLCD land cover individual developed classes within the group patch are now represented by a single pixel MMU to retain the direct linkage to the imperviousness product."
Downloaded National Land Cover Database product (nlcd_2011_impervious_2011_edition_2014_10_10.zip) from the Multi-Resolution Land Characteristics (MRLC) Consortium Web site <http://www.mrlc.gov/nlcd11_data.php> in ERDAS imagine IMG format. The data were projected to Universal Transverse Mercator, Zone 16, NAD 1983. ESRI ArcToolbox, Spatial Analyst Tools, Extraction, Extract by Mask was used to "clip" the image to the Indiana state boundary using a raster mask, while retaining the full attribute table. The resultant geodatabase was exported to TIFF format for distribution to those without access to ESRI products.
This metadata file was pre-parsed and parsed using CNS (Chew and Spit, v. 2.6.1) and MP (Metadata Parser, v. 2.7.1) software written by Peter N. Schweitzer (U.S. Geological Survey). The errors generated by MP were all addressed and corrected.

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