To address accuracy concerns of the National Land Cover Dataset (NLCD), this case study compares impervious surface from the NLCD to a Detailed Land Cover Dataset (DLCD) for the Town of Blacksburg, Virginia over two time periods (2005/2006 and 2011) at spatial aggregation scales (fine to coarse) and scopes (site-specific to area-extent). When comparing the total impervious surface area, the NLCD overestimated the DLCD by appreciable amounts (12-27%) for the entire town and across all specified land use zones for both time periods examined. A binary pixel-wise accuracy assessment of impervious surface revealed that the NLCD performed well for all scopes except for the single family land use zone (user accuracy <40%). The spatial aggregation of pixels to 90-m led to improved agreement between the two datasets. Using the DLCD as a reference, an empirical normalization equation was successfully applied to the NLCD to further reduce overestimation and data skewness. / Master of Science / To address accuracy concerns of the National Land Cover Dataset (NLCD), this case study compares impervious surface conditions from the NLCD to a Detailed Land Cover Dataset (DLCD) for the Town of Blacksburg, Virginia over two time periods (2005/06 and 2011) at various spatial scales and scopes. When comparing the total impervious surface area, the NLCD overestimated the DLCD by appreciable amounts for the entire town and across all specified land use zones for both time periods examined. A comparison at the pixel level revealed the NLCD performed well for all scopes except for the single family residential land use zone. Although there was improved agreement between the datasets at coarser resolutions, data skewness was still apparent. By using the DLCD as a ground truth reference, a mathematical correction equation was applied to the NLCD to better align it with the DLCD. Reflected through this assessment, inaccuracies within the NLCD need to be further studied to assist local and regional governments to more correctly depict land cover conditions for applications such as land use planning and stormwater management.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/72869 |
| Date | 01 September 2016 |
| Creators | Cooper, Brandon Elliott |
| Contributors | Civil and Environmental Engineering, Dymond, Randel L., Young, Kevin D., Shao, Yang |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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