w_intersect: Intersect a river feature with a polygon feature
In flee-group/watershed: Tools for Watershed Delineation

w_intersect

R Documentation

Intersect a river feature with a polygon feature

Description

w_intersect handles the use case where we want to summarize areal features, such as land use, soils, etc, across reaches of a river, while taking into account drainage area, flow, etc.

Usage

w_intersect(
  riv,
  areas,
  area_id = NULL,
  drainage,
  pts,
  buff = 50,
  rid = "reach_id"
)

Arguments

`riv`	An sf LINESTRING layer, the river channel
`areas`	Areal features to summarize; see 'details.'
`area_id`	Optional character vector giving field/column names that should be summarised; see 'details.'
`drainage`	Drainage direction raster for calculating catchment
`pts`	An `sf` point layer, one point per reach; the locations to compute the catchment of each reach. If missing, the last point in each reach in `riv` is used.
`buff`	Buffer width
`rid`	The column name in 'riv' containing reach ID numbers

Details

There are three output types:

riparian: The layers in areas are summarized within a riparian buffer around each reach
riparian_upstream: The layers in areas are summarized within a riparian buffer for each focal reach and all upstream reaches
catchment: The layers in areas are summarized within the entire catchment for each reach

areas must be in one of the following formats: terra::SpatRaster, raster::raster, sp::SpatialPolygons, or sf::sf. Multiple features are allowed, in which case provide a raster stack/multi band raster, or a list of polygon features.

If polygon features are specified in areas, you must also specify which attributes should be summarised in area_id. Currently a single attribute per feature is supported, and it must be specified by name, not column index. Partial matching with regular expressions is allowed, but each item in area_id must identify a single column in areas. Ignored if areas is a raster.