get_DD {nhdplusTools} | R Documentation |
Navigate Downstream with Diversions
Description
Traverse NHDPlus network downstream with diversions NOTE: This algorithm may not scale well in large watersheds. For reference, the lower Mississippi will take over a minute.
Usage
get_DD(network, comid, distance = NULL)
Arguments
network |
data.frame NHDPlus flowlines including at a minimum: COMID, DnMinorHyd, DnHydroseq, and Hydroseq. |
comid |
integer identifier to start navigating from. |
distance |
numeric distance in km to limit how many COMIDs are returned. The COMID that exceeds the distance specified is returned. The longest of the diverted paths is used for limiting distance. |
Value
integer vector of all COMIDs downstream of the starting COMID
Examples
library(sf)
start_COMID <- 11688818
source(system.file("extdata", "sample_flines.R", package = "nhdplusTools"))
DD_COMIDs <- get_DD(sample_flines, start_COMID, distance = 4)
plot(dplyr::filter(sample_flines, COMID %in% DD_COMIDs)$geom,
col = "red", lwd = 2)
DM_COMIDs <- get_DM(sample_flines, start_COMID, distance = 4)
plot(dplyr::filter(sample_flines, COMID %in% DM_COMIDs)$geom,
col = "blue", add = TRUE, lwd = 2)
[Package nhdplusTools version 1.2.1 Index]