Mapping some lake data

lake_data_map.R

# Mapping some lake data
# Reference: https://r-spatial.org/r/2018/10/25/ggplot2-sf.html

library(sf) # create geospatial layers
library(rnaturalearth) # basemap
library(ggplot2) # plotting
library(tidyr)
library(scales)

dt <- read.csv("lake_data_file.csv", stringsAsFactors = FALSE)
dt_sf <- st_as_sf(dt, coords = c("lon", "latitude"), crs = 4326)
bbox <- st_as_sfc(st_bbox(dt_sf))

states_all   <- ne_states(
  country = c(
    "united states of america", "canada"
), returnclass = "sf")
states <- states_all[
  unlist(lapply(st_intersects(states_all, bbox), function(x) length(x) > 0)), ]

ggplot() +
  geom_sf(data = states, fill = "antiquewhite") +
  geom_sf(
    data = tidyr::drop_na(dt_sf, tp_mean), aes(color = tp_mean), size = 1) +
  scale_color_viridis_c(trans = "log", name = "TP",
    labels = scales::number_format(accuracy = 1)) +
  coord_sf(
    xlim = as.numeric(st_bbox(dt_sf))[c(1, 3)],
    ylim = as.numeric(st_bbox(dt_sf))[c(2, 4)], expand = FALSE) +
  theme_bw() +
  theme(panel.background = element_rect(fill = "aliceblue"))
ggsave("test.png")