To improve the performance of the web applications displaying the 2012 impervious surface data, it was necessary to create a new simplified layer that included only the minimum number of polygons and attributes needed to represent the 2012 impervious surface conditions. This new layer, IS12, was created using the following steps: The 2012 impervious surface coverage, IS12, was created by dissolving on the field, IS12. Error checks as described above were run on the dissolved coverage, any needed corrections made, and the coverage IS12 was then loaded into the SDE geo-database for use in the web applications.
The 2007 land use/land cover data set was displayed over 2012 CIR digital imagery. New line work and codes needed to describe the land use conditions interpreted from the 2012 imagery were added directly to the 2007 layer through interactive editing. Photo-interpretation, interactive editing, field surveys and initial QA/QC done by Aerial Information Systems, Redlands, CA, under the direction of the NJDEP/BGIS. The baseline 2007 data sets edited in this project were prepared by NJDEP/BGIS, from the original 2007 Land Use/Land Cover Update layers. The original layers included both 2007 and 2002 land use codes and linework. The 2002 codes and linework were removed by dissolving on the critical 2007 land use attributes. This produced layers that included only the 2007 codes and linework. It was these dissolved layers that were edited in this present project . Final QA/QC and final data set formatting for the 2012 update layers was done by NJDEP/BGIS. Land use/land cover in 2012 was captured by adding additional line work and codes to the base layer, and filling in specific attribute fields that describe the 2012 land use/land cover ground conditions. All 2007 codes and line work remain in the data set so that change analysis can be performed on all polygons using this one updated data set. The 2007 polygons and codes were updated if it was felt that original mapped lines or land use classifications of any 2007 polygon needed to be modified based on the better 2012 imagery. In addition to the lu/lc codes, an impervious surface estimate was made for every polygon. This was a visual estimate and not a measured value. Data sets were processed and delivered by USGS Subbasin (HU8).
The attributes in this data set describe land use/land cover categories for Percent impervious surface for each polygon from 2012.