Whether a natural barrier to a species lies downstream of each point

scripts/0296's access test, per species. link applies a habitat rule behind its access gate, and the gate's observation overrides come mostly from these same electrofishing records, so a rule scored on them must use the barriers as they stood before overrides: GRADIENT, FALLS, SUBSURFACE_FLOW and USER_DEFINITE rows of the schema's barriers table that block the species (blocks_species), tested with fwa_downstream() from the point.

Usage

knw_link_barrier_dnstr(
  conn,
  pts,
  species,
  schema,
  natural = c("GRADIENT", "FALLS", "SUBSURFACE_FLOW", "USER_DEFINITE")
)

Arguments

conn

a DBI connection to a database holding schema.

pts

data.frame with blue_line_key, downstream_route_measure, wscode and localcode (ltree text). A point with no codes gets NA.

species

character species codes, each tested on its own.

schema

character(1) link persist schema.

natural

character the barrier sources that count as natural.

Value

A tibble of the distinct pts keys with one logical column barrier_dnstr_<sp> per species (lower case).

Examples

if (FALSE) { # \dontrun{
conn <- DBI::dbConnect(RPostgres::Postgres())
pts <- data.frame(blue_line_key = 360886335, downstream_route_measure = 1520,
                  wscode = "400.431358.785328", localcode = "400.431358.785328.000001")
knw_link_barrier_dnstr(conn, pts, c("BT", "CH"), "fresh_default")
} # }