7. Riverspace delineation

library(rcrisp)
library(sf)

bucharest_osm <- get_osm_example_data()
bucharest_dem <- get_dem_example_data()

River space delineation is a delineation step that uses the river and buildings as input to generate a polygon representing the space between the river and the first line of buildings. We will use River Dâmbovița of Bucharest as the river and the buildings surrounding it as input.

buildings <- bucharest_osm$buildings
river <- bucharest_osm$river_surface

The delineate_riverspace() function takes the building polygons and the river (including surface polygons and centerline) as input. The river surface polygons intersecting the river centerline are treated as part of the river, including connected water bodies such as lakes and reservoirs. Viewpoints are calculated from water edges where available, and from the river centerline when river surface polygons are missing or partial. If no river is provided, it will return an error message. If no buildings are provided, it will return an unobstructed buffer of a given radius with a warning message. The function returns an sf polygon.

riverspace <- delineate_riverspace(river, buildings)

We visualise the riverspace in a subset of segments.

riverspace_segment_2_4 <- riverspace |>
  st_intersection(bucharest_dambovita$segments[2:4])

buildings_segment_2_4 <- buildings |>
  st_sf() |>
  st_filter(bucharest_dambovita$segments[2:4], .predicate = st_intersects) |>
  st_filter(riverspace_segment_2_4, .predicate = st_intersects)

plot(riverspace_segment_2_4, col = "orange", border = NA)
plot(buildings_segment_2_4, add = TRUE)