Hawke’s Bay catchment models

1 Introduction

If you haven’t already seen, I’ve invited catchment groups to get in touch with me if they’re interested in getting a topographic model of their catchment, and one exciting possibility is printing adjoining catchments at a common scale to fit together like a jigsaw puzzle. This is exactly what the Hawke’s Bay Regional Council (HBRC) requested—a model of all 11 major catchments that fit together to form the entire region.

2 Puzzle pieces

HBRC provided a shapefile of the 11 catchment groupings, conveniently prepared with coincident borders.

library(leaflet)
library(sf)

# Load the catchments data
catchments <- readRDS("hbrc_catchments.RDS")

# Make sure the data is projected correctly for Leaflet
catchments <- st_transform(catchments, crs = 4326) # Convert to WGS84

# Create a color palette for the categorical EMA field
ema_palette <- colorFactor(palette = "Set3", domain = catchments$EMA)

# Create a leaflet map
leaflet(catchments) |>
  addProviderTiles("Esri.WorldImagery") |>
  addPolygons(
    fillColor = ~ema_palette(EMA),
    weight = 2,
    opacity = 1,
    color = 'white',
    dashArray = '3',
    fillOpacity = 0.9,
    highlightOptions = highlightOptions(
      weight = 5,
      color = "#666",
      dashArray = "",
      fillOpacity = 0.5,
      bringToFront = TRUE
    ),
    label = ~EMA,
    popup = ~EMA
  )