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coast

Distance to the nearest shoreline, from GSHHG shoreline polygons.

geoenrich coast <INPUT> --data <GSHHG> [OPTIONS]

Appends one column, dist_to_coast (rename with --column), holding the distance from each point to the nearest coastline in kilometers (default) or meters (--unit m).

How it works

The GSHHG L1 (land / ocean) boundary segments are cropped to the region box plus a 5 degree margin, projected through the region’s Lambert Azimuthal Equal-Area (LAEA) projection into meters, and indexed in an R-tree. Each point is projected the same way and takes the planar distance to the nearest segment. Segments are dropped, never clipped, so cropping cannot invent artificial shoreline; a point whose true nearest coast lies beyond the region-plus-margin box gets an over-estimate, so widen the region for such cases.

Options

Beyond the shared options and the region options:

OptionDefaultMeaning
--data <PATH>requiredGSHHG shapefile directory (resolution f recommended) or a GSHHS_*_L1.shp file
--unit <km|m>kmDistance unit for the output column
--column <NAME>dist_to_coastOutput column name

Example

geoenrich coast cores.parquet \
  --data ./data/gshhg/gshhg-shp-2.3.7/GSHHS_shp/f \
  --unit km -o cores.coast.parquet

See Reference datasets for how to obtain GSHHG.