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FEMA Flood Hazard Zone Preliminary Difference Areas

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This metadata information is subject to our disclaimer. Metadata information presented here is maintained manually. Therefore, date-sensitive fields such as feature count and date of last update may not be up-to-date. All metadata is subject to errors inherent in a manual process.

Descriptive nameFEMA Flood Hazard Zone Preliminary Difference Areas
File namefp_dfdif
Spatial domainPima County
AbstractThis layer enables display of areas where the current regulatory D-FIRM data (fp_dfirm) and the preliminary 2010 D-FIRM data (pf_dfirm) are different. Attributes identify the zone attributes in each of the two FIRM datasets. fp_dfdif is intended to assist the review process by displaying areas where the flood zones or zone designations have changed.
Known errors/qualificationsUser must filter (OLDZONE <> NEWZONE) to show just the differences. There are many small sliver areas that are not meaningful. Filtering out small areas with high perimeter to area ratios may be useful. The SLIVER field is a calculated ratio of the area and perimeter of each polygon. Filtering for SLIVER > 0.5 is a method to remove sliver polygons. It may also be helpful to filter out very small areas that don't have "sliver" shape, such as areas less than 250 square feet.
Feature typepolygon
Feature count 2,657
Thumbnail Map fp_dfdif.pdf PDF file format   (2,072,907 bytes, PDF created 07/19/2022 )
ProjectionNAD83 HPGN (Parameters)
RectificationFIRM panels
Field/value metadata Field metadata
Source organizationPCRFCD
Source contactKenneth Maits
Source document or file namefp_dfirm and pf_dfirm
Source date20090617
Source scale
Source formatShape
Date of last data update
(This date may not be current.)
Last data update byKenneth Maits
Date/time last touched - Meaning? 2021-04-25  11:50 PM - Enterprise GDB
  2021-04-25  11:50 PM - Shapefile - Library input format
  See coverage files, if any, for date.
On maintenance?No
Maintenance organizationPCRFCD
Maintenance description
Original conversion byKenneth Maits
Pima County ITD GIS contactKenneth Maits
Alternate Pima County ITD GIS contacte-mail address
On  Pima County Geospatial Data Portal? No

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