make_standalone {nhdplusTools}

Make isolated NHDPlusHR region a standalone dataset

Description

Cleans up and prepares NHDPlusHR regional data for use as complete NHDPlus data. The primary modification applied is to ensure that any flowpath that exits the domain is labeled as a terminal path and attributes are propagated upstream such that the domain is independently complete.

Usage

make_standalone(flowlines)

Arguments

flowlines

sf data.frame of NHDPlusHR flowlines.

Value

sf data.frame containing standalone network

Examples

library(dplyr)
library(sf)
source(system.file("extdata/nhdplushr_data.R", package = "nhdplusTools"))

(outlet <- filter(hr_data$NHDFlowline, Hydroseq == min(Hydroseq)))
nrow(filter(hr_data$NHDFlowline, TerminalPa == outlet$Hydroseq))

hr_data$NHDFlowline <- make_standalone(hr_data$NHDFlowline)

(outlet <- filter(hr_data$NHDFlowline, Hydroseq == min(Hydroseq)))
nrow(filter(hr_data$NHDFlowline, TerminalPa == outlet$Hydroseq))

source(system.file("extdata/nhdplushr_data.R", package = "nhdplusTools"))

# Remove mainstem and non-dendritic stuff.
subset <- filter(hr_data$NHDFlowline,
                        StreamLeve > min(hr_data$NHDFlowline$StreamLeve) &
                          StreamOrde == StreamCalc)

subset <- subset_nhdplus(subset$COMID, nhdplus_data = hr_gpkg)$NHDFlowline

plot(sf::st_geometry(hr_data$NHDFlowline))

flowline_mod <- make_standalone(subset)

terminals <- unique(flowline_mod$TerminalPa)

colors <- sample(hcl.colors(length(terminals), palette = "Zissou 1"))

for(i in 1:length(terminals)) {
  fl <- flowline_mod[flowline_mod$TerminalPa == terminals[i], ]
  plot(st_geometry(fl), col = colors[i], lwd = 2, add = TRUE)
}

ol <- filter(flowline_mod, TerminalFl == 1 & TerminalPa %in% terminals)

plot(st_geometry(ol), lwd = 2, add = TRUE)