| description:
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HUC12s in this layer intersect Forest System boundaries
WBD data sources:
-Non-Alaska – ‘WBD_Poly_Seamless.xml’ included in ‘Metadata’ folder
-Alaska – ‘WBD_National_GDB.xml’ included in ‘Metadata’ folder
WHPA description – Wellhead Protection Areas
-Catchments including GW Wells in non-AK
-1 mile buffers for GW Wells in AK, since no catchments are available for AK in NHDPlus V2.1
Area Calculation description:
‘Percentage of HUC12 covered by Wellhead Protection Area’ is calculated using the US area of the HUC12 and WHPA features (NHDPlus V2.1catchments). The HUC12s are further clipped using the processing extent of the NHDPlus V2.1. This ensures that all HUC12 features are covered by NHDPlus V2 catchments, notably in coastal areas where the HUC12s extend into the ocean.
WHPA features in Alaska were dissolved before calculating ‘Percentage of HUC12 covered by Wellhead Protection Area’ to avoid over-counting in areas where WHPA features overlap.
Catchment data source:
- ‘NHDPlusV2_metadata.xml’ included in ‘Metadata’ folder |