Differences between GIS calculated acreage and tabular data

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{{#customtitle:A land unit downloaded from NRCS has a different acreage in the map than the acreage shown in the tabular data - what should be done? |A land unit downloaded from NRCS has a different acreage in the map than the acreage shown in the tabular data - what should be done?}}

When you donwload Land Unit boundaries from the National Conservation Planning Database (NCPDB), as detailed in this article, there may be differences between digitized acreage, and acreage data in the tabular data. For instance, in the example below you will see the image on the left side showing a land unit's acreage according to NCPDB tabular data, while the one to the left will show the GIS-calculated acreage.

Tabular data acreage Digitized acreage

This acreage may be a known or certified amount, which could be different from what is calculated 'as-digitized' in the map. In most cases there should not be a significant difference.

TSPs may encounter bad data occasionally. If a TSP thinks that the acreage is not accurate, he or she can follow the guidance below

  • If the bad data directly impacts the work of the TSP, the TSP should contact the NRCS Office to verify the information. The TSP and NRCS should work together to determine if the information needs to be corrected.
  • If the incorrect information does not impact the TSP’s planning efforts, there is no need to contact the NRCS office. This will aid in avoiding delays and reduce unnecessary workload on the NRCS field staff. The TSP may want to provide a note or comment to NRCS when the plan is checked back in to make the office aware of potential problem. NRCS is aware that bad data exists in the database and efforts are being made to clean up the problems.