Bathy_sf: Bathy_sf metadata

In Maritimes/Mar.data: Data used by one of more of the Maritimes packages

Bathy_sf metadata

Description

An sf polygon showing bathymetric features as polygons. This file is based off of the gebco_2021_polys file from https://www.opendem.info/download_bathymetry.html. That file has bathymetries starting at -25m, leaving "halos" around all land. To fix this, an accurate coastline was downloaded from https://osmdata.openstreetmap.de/data/coastlines.html, and the areas between the land in this file and the gebco polygons were inferred to be 0-25 m. For convenience, the land areas were left in the file, identified as type="land", and assigned the values of 1 and 0 as the DEP_MIN_M and DEP_MAX_M, respectively. the The following contours are included: * 1 : 0 m (i.e. all land); * 0 : - 25 m; * - 25 : - 50 m; * - 50 : - 100 m; * - 100 : - 200 m * - 200 : - 250 m; * - 250 : - 500 m; * - 500 : - 750 m; * - 750 : -1050 m; * -1050 : -1250 m; * -1250 : -1500 m; * -1500 : -1750 m * -1750 : -2000 m * -2000 : -2500 m * -2500 : -3000 m * -3000 : -3500 m * -3500 : -4000 m * -4000 : -4500 m * -4500 : -5000 m * -5000 : -5500 m * -5500 : -6000 m

Usage

Bathy_sf

Format

sf polygon

DEP_MIN_M

The minimum depth (m) found within the polygon

DEP_MAX_M

The maximum depth (m) found within the polgon

FEAT_TYPE

Identifier differentiating 'marine' and 'land' features

Examples

if (require(ggplot2) && require(sf)) {
  #plot the bathymetry
  ggplot(Bathy_sf) +
    geom_sf(aes(fill = DEP_MIN_M), color = NA) +
    scale_fill_gradientn(colors = c("darkgreen", "darkblue", "lightblue"),
    values = scales::rescale(c(1, min(Bathy_sf$DEP_MIN_M, na.rm = TRUE), max(Bathy_sf$DEP_MIN_M, na.rm = TRUE))),
    guide = "colorbar") +
    theme_minimal() +
    labs(title = "Bathy_sf Plot", fill = "DEP_MIN_M")
  #just plot the coastline
  ggplot() +
    geom_sf(data = Bathy_sf[Bathy_sf$DEP_MIN_M == 0, ], fill='darkgreen') +
    theme_minimal() +
    labs(title = "Bathy_sf Coastline Plot", fill = "DEP_MIN_M")
}

Maritimes/Mar.data documentation built on Nov. 5, 2024, 5:11 p.m.