Conservation land correction fractions for NPS/MS4 allocation assessment
Source:R/conserv_correction.R
conserv_correction.RdConservation land correction fractions for NPS/MS4 allocation assessment
Format
A data frame with one row per unique bay segment, basin, entity, and CLUCSID combination where conservation land is present:
- bay_seg
Integer bay segment identifier (1 = OTB, 2 = HB, 3 = MTB, 4 = LTB, 55 = RALTB).
- basin
Character drainage basin identifier.
- entity
MS4 jurisdiction name.
- clucsid
Integer Coastal Land Use Classification System identifier.
- conserv_frac
Fraction of entity area x runoff-coefficient attributable to conservation land within that bay segment / basin / CLUCSID combination. Computed as conservation area x RC divided by total entity area x RC (conservation + non-conservation) for that group.
Source
Derived from data-raw/npsag_3_2224_25Sep25.sas7bdat, the SAS
NPS land cover file. Built by data-raw/conserv_correction.R.
Details
The tbeploads-built tbbase is derived from routinely updated
GIS sources (land use, soils, jurisdictions) and does not include a
conservation land spatial overlay. The conservation layer was available
only for prior SAS workflows and cannot reproduced.
conserv_correction provides entity-specific fractions derived from
the SAS land cover file (npsag_3_2224_25Sep25.sas7bdat), which
includes a binary conservation column (0/1) indicating conservation
land while retaining the original MS4 jurisdiction in entity. Within
anlz_aa, each MS4 entity's disaggregated TN load for a given
basin and CLUCSID is scaled by (1 - conserv_frac) to remove the
conservation land contribution before hydrologic normalization.
Preprocessing matches util_aa_npsfactors: non-contributing
drainage (drnfeat = "NONCON") and water / tidal CLUCSIDs (17, 21, 22)
are excluded, compound hydrologic soil groups are simplified, and nested basins
are remapped. Only entity, basin, CLUCSID combinations with
conserv_frac > 0 are retained.