Crossing Connectivity Interpretation • link

Crossing connectivity interpretation for fish passage.

link is the domain layer between raw crossing data and fresh’s generic network engine. It scores, overrides, and prioritizes crossings using configurable severity thresholds and multi-source data integration.

Crossings are features on the network. Some break geometry (confirmed barriers fed to fresh as break sources). Others just index for downstream relationship queries (unassessed crossings, observations).

Installation

pak::pak("NewGraphEnvironment/link")

Data sources

No database required for the core pipeline:

Data	Source
Crossings (province-wide)	`fresh::system.file("extdata", "crossings.csv")`
PSCIS assessments	`bcdata::bcdc_get_data("7ecfafa6-...")`
Override CSVs	`bcfishpass/data/` directory
Habitat thresholds	`fresh::system.file("extdata", "parameters_habitat_thresholds.csv")`

What it does

bcfishpass CSVs (overrides) --> link (interpret, score) --> break source spec --> fresh
fresh CSV (crossings)       -->
bcdata (PSCIS assessments)  -->

Override corrections — load and apply hand-reviewed crossing fixes accumulated across field seasons
Multi-source matching — link PSCIS assessments, modelled crossings, and MOTI culvert inventory using network position
Severity scoring — classify crossings by biological impact (high/moderate/low) using actual measurements, not binary BARRIER/PASSABLE
Break source bridge — produce specs that plug directly into frs_habitat(break_sources = ...)

Quick start

library(link)

# Load crossings from fresh CSV
crossings <- read.csv(
  system.file("extdata", "crossings.csv", package = "fresh"))
morr <- crossings[crossings$watershed_group_code == "MORR", ]

# Load and apply override corrections (DB needed for SQL operations)
conn <- lnk_db_conn()
lnk_override_load(conn, csv = "overrides.csv", to = "working.fixes")
lnk_override_apply(conn, "working.crossings", "working.fixes")

# Score severity
lnk_score_severity(conn, "working.crossings")

# Feed to fresh
src <- lnk_break_source(conn, "working.crossings")
fresh::frs_habitat(conn, "MORR", break_sources = list(src))

See vignette("scoring-crossings") for the full pipeline on the Morice (MORR) watershed group — the same steps scale to any watershed group for provincial coverage.