FWA-Referenced Spatial Hydrology
Stream network-aware spatial operations via direct SQL against fwapg and bcfishpass. Snap points to streams, delineate watersheds, query fish observations, and fetch network-referenced features from the BC Freshwater Atlas.
Installation
pak::pak("NewGraphEnvironment/fresh")Prerequisites
fresh requires PostgreSQL with the following extensions loaded:
- fwapg — BC Freshwater Atlas in PostgreSQL
- bcfishpass — fish passage and habitat modelling
- bcfishobs — fish observation data
Connection is configured via PG_*_SHARE environment variables (PG_HOST_SHARE, PG_PORT_SHARE, PG_DB_SHARE, PG_USER_SHARE) or passed directly to frs_db_conn().
Example
Query all network features between two points on the same blue line key using watershed code subtraction — no spatial clipping needed:
library(fresh)
result <- frs_network(
blue_line_key = 360873822,
downstream_route_measure = 208877,
upstream_measure = 233564,
tables = list(
streams = "whse_basemapping.fwa_stream_networks_sp",
lakes = "whse_basemapping.fwa_lakes_poly",
fish_obs = "bcfishobs.fiss_fish_obsrvtn_events_vw",
falls = "bcfishpass.falls_vw"
)
)See the subbasin vignette for a full worked example with map output.
Ecosystem
fresh is one piece of a larger watershed analysis workflow:
| Package | Role |
|---|---|
| fresh | FWA-referenced spatial hydrology (this package) |
| breaks | Delineate sub-basins from break points on stream networks |
| flooded | Delineate floodplain extents from DEMs and stream networks |
| drift | Track land cover change within floodplains over time |
| fly | Estimate airphoto footprints and select optimal coverage for a study area |
| diggs | Interactive explorer for fly airphoto selections (Shiny app) |
Pipeline: fresh (network data) → breaks (sub-basins) → flooded (floodplains) → drift (land cover change)