pretty_rivers/02_process_data.R

# load libraries
library(nhdplusTools)
library(sf)

# reload extent data so you don't need to run the download data script again
data_dir <- "data"
nhdplusTools_data_dir(dir = paste0(data_dir, "/hydrologic"))

extent <- read.csv(file = "extent.csv")
crs <- 4269

extent_poly <- st_polygon(
  x = list(
    cbind(
      extent$longitude[c(1,2,2,1,1)], 
      extent$latitude[c(1,1,2,2,1)])
  )
)

extent_poly <- st_sfc(extent_poly, crs=4326)
extent_bbox <- st_bbox(st_transform(x = extent_poly, crs))
extent <- list(longitude_max = max(extent$longitude),
               longitude_min = min(extent$longitude),
               latitude_max = max(extent$latitude),
               latitude_min = min(extent$latitude))

# load and crop hydrologic data
data <- list(NULL)
sf_use_s2(FALSE)
layers <- c("NHDArea",
            "NHDFlowline",
            "NHDWaterbody",
            "NHDPlusLandSea")
for (layer in layers){
  data[[layer]] <- st_crop(st_read(paste0(nhdplusTools_data_dir(),"/data.gpkg"), layer = layer), y = extent_bbox)
}

# load political boundaries
political <- list(NULL)
political_boundaries <- list.files(path = paste0(data_dir, "/political_boundaries"))
for (boundary in political_boundaries) {
  political[[boundary]] <- st_read(paste0(data_dir, "/political_boundaries/", boundary))
}