Similar to the heads-up process used in the 1995 and 2002 updates, the 2007 update layers were created by examining the existing 2002 LU/LC layers from the NJDEP GIS database over the 2007 color infrared digital imagery. Areas which had undergone no changes in the 2002 to 2007 time period simply have the 2002 codes moved into similar 2007 attribute fields. For those areas undergoing any changes, new line work and codes are added as needed to appropriately capture the change. As with the previous updates, these 2007 layers retain all of the codes and line work defining the 2002 ground conditions so that analyses between 2002 and 2007 can be done directly from the 2007 update layers.

Note that some modifications to the baseline 2002 data have been made during the 2007 update, as has occurred during the previous updates. There are several reasons for this. First, several new categories were mapped for the 2007 update, most importantly rail lines and railroad facilities. While some of these rail facilities were previously included in the general category of Transportation/ Communications/Utilities, most of the individual rail tracks and rights-of-way were not. As these rail lines and facilities were mapped, 2002 codes were adjusted if these features were also present in 2002. This has the effect of modifying the 2002 acreage values of several land use categories.

Second, there was an increased effort in this 2007 update to map additional water features that may have been previously overlooked. The water features from the LU/LC data sets, both the 2002 data and the 2007 data, are being used to populate the New Jersey portion of the National Hydrography Database (NHD), which is a nation-wide database created by USGS to house all water features in the nation. NJDEP has taken over the stewardship of this important NHD data set, and is working to get the most detailed and accurate water feature data into the system. In this effort, many additional water features previously unmapped were captured during this 2007 update.

Third, as has been the practice with previous updates, there are other instances throughout the data set where 2002 codes or line work have been adjusted before the 2007 edits were made. This is due in large part to having better imagery available that enables delineators to refine polygon classifications and line placements to more accurately map the landscape. These changes also affect the acreage values of many categories previously reported with the original 2002 data. For all of these reasons, note that category acreage values reported previously in the 2002 data set may differ from the values for the same categories when using the 2002 codes from the latest 2007 update.

As stated in this metadata record's Use Constraints section, NJDEP makes no representations of any kind, including, but not limited to, the warranties of merchantability or fitness for a particular use, nor are any such warranties to be implied with respect to the digital data layers furnished hereunder. NJDEP assumes no responsibility to maintain them in any manner or form. By downloading this data, user agrees to the data use constraints listed within this metadata record.