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Update the State of Delaware's existing 2007 Impervious Surface data layer to 2012 conditions. To identify impervious surfaces for the purpose of modeling such as stormwater, and atmospheric pollutant modeling. The dataset is suitable for many planning and modeling purposes but its primary purpose was to aid in the development of the 2012 Land Use Land Cover Update. |
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Update the State of Delaware's existing 2007 Impervious Surface data layer to 2012 conditions. To identify impervious surfaces for the purpose of modeling such as stormwater, and atmospheric pollutant modeling. The dataset is suitable for many planning and modeling purposes but its primary purpose was to aid in the development of the 2012 Land Use Land Cover Update. |
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Mapped by Aerial Information Systems, Inc. of Redlands, California for the Delaware Office of State Planning |
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5000 |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The State’s first Impervious Surface (IS) dataset was created as a by-product of the previous vendor’s “change detection” image processing update methodology. The resulting impervious surface data, while not of the highest accuracy, was deemed an acceptable representation of IS in the state. The impervious surface data for the 2012 Update was produced to the same level as the State’s previous datasets, per the project requirements. The work was performed by Aerial Information Systems, Inc. (AIS), located in Redlands, California. The 2012 Impervious Surface data layer was created using a combination of Automated Feature Extraction (AFE) techniques and ArcGIS raster data editing tools. Approximately 2,000 image tiles provided complete coverage of the State. These images were composed of four bands (red, blue, green and IR) at a resolution of 1 foot (0.33 meter). The automated feature extraction involved a number of processing steps and the use of two software products: Genie Pro 2.4, by Obervera, Inc., was used to perform the automated feature extraction and Esri’s ArcGIS was used to perform image cleanup and editing tasks. Using Genie Pro 2.4, training sets and solution files were created and prepared on a representative sample of image tiles. Then the training sets and solution files were combined into one master solution file. Using a python script, all image tiles were processed with the master solution file to create new image tiles. Each of the new image tiles was reviewed to verify that processing step was successfully completed. Where processing problems occurred, the image tiles were re-processed. The analyst revised the original training sets and created new solution files to produce a new result image tile. This process was repeated until the processing errors were corrected. Using ArcMap raster processing tools, four raster catalogs were created which closely matched the extent of the 2007 Impervious Surface raster images. Each of these layers were made up of approximately 500 image tiles. The following series of processing steps were run on each of the four layers: The images were resampled from 0.33 meters to match the 1 meter resolution of the original 2007 IS data. Small mis-identified pixels were removed from each of the four images by running them through the following five processes: Majority Filter, Boundary Clean, Region Group, Set Null, and Nibble. The analyst performed a manual review and edit of each image using ArcMap and the ArcScan extension. The final Impervious Surface geodatabase was created and each of the four regional impervious surface raster data files were imported to the geodatabase.</SPAN></P></DIV></DIV></DIV> |
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<DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The State of Delaware makes no warranty or representation, expressed or implied, with respect to the quality, content, accuracy, completeness, currency, or non-infringement of proprietary rights, of any of the GIS or other data or information, or any other materials and items, that are displayed or made available for download from this site. All such data, information, items and materials (collectively, the “FirstMap Data”) are provided "as is" and users are fully and solely responsible for any consequences of use. FirstMap Data may have been created from a variety of sources, including sources beyond the control of the State of Delaware, and are subject to change without notice. To the extent you use, apply, add to, modify or implement this information in your own information system or other setting, or otherwise for your own purposes, you do so at your own risk. In no event shall the State of Delaware or its agencies, officers, employees, agents, or representatives be liable for any damages of any kind or nature whatsoever including, but not limited to, direct, indirect, special, punitive, incidental, exemplary or consequential damages arising from your downloading, modifying, sharing, distributing, or using of FirstMap Data even if notified of the possibility of such damages. Further, the State of Delaware does not accept liability for any damages or misrepresentation caused by inaccuracies in the FirstMap Data or as a result of changes to the FirstMap Data, nor is there responsibility assumed to maintain the FirstMap Data in any manner or form.</SPAN></P></DIV></DIV></DIV> |
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| title:
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2012 Impervious Surface Data |
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["United States of America (USA)","Mid Atlantic","Delaware (DE)","Kent County","New Castle County","Sussex County","Imagery","BaseMaps","EarthCover","Impervious Surface","LandUseLandCover","Structure"] |
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en-US |
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150000000 |
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