VicmapR

The goal of VicmapR is to provide functions to easily access Victorin Government spatial data through their WFS (Web Feature Service). The package is currently in an early development stage.

Installation

You can install the the development version from GitHub with:

# install.packages("remotes")
remotes::install_github("JustinCally/VicmapR")

Dependencies

Currently, the ability to use accurate geometric filters using VicmapR requires GDAL > 3.0. To see how to upgrade your version of GDAL and link it to the sf package visit: https://r-spatial.github.io/sf/#installing

library(sf)
#> Linking to GEOS 3.6.1, GDAL 2.2.3, PROJ 4.9.3
sf::sf_extSoftVersion()
#>           GEOS           GDAL         proj.4 GDAL_with_GEOS     USE_PROJ_H 
#>        "3.6.1"        "2.2.3"        "4.9.3"         "true"        "false"

Example

Searching for data

library(VicmapR)
#> 
#> Attaching package: 'VicmapR'
#> The following object is masked from 'package:stats':
#> 
#>     filter

listLayers(pattern = "trees", ignore.case = T)
#>                                Name
#> 1 datavic:WATER_ISC2010_LARGE_TREES
#>                                                           Title
#> 1 2010 Index of Stream Condition - Large Trees polygon features

Reading in data

As of VicmapR version 0.1.0 data is read in using a lazy evaluation method with the convenience of pipe operators (%>%). A lot of the methods and code have already been written for a similar package (bcdata) that downloads data from the British Columbia WFS catalogue. Using a similar approach to bcdata, VicmapR allows users to construct a WFS query in a step-wise format. In doing so a query is reserved until collect() is used on the vicmap_promise. The example below shows an extensive example of how the to easily read in spatial data:

# Read in an example shape to restrict our query to using geometric filtering
melbourne <- sf::st_read(system.file("shapes/melbourne.geojson", package="VicmapR"), quiet = T)

# Obtain a promise of what data will be returned for a given layer
vicmap_query(layer = "datavic:VMHYDRO_WATERCOURSE_DRAIN")
#> * Using collect() on this object will return 187446 features and 16
#> * fields
#> * At most six rows of the record are printed here
#> ------------------------------------------------------------------------------
#> Simple feature collection with 6 features and 15 fields
#> geometry type:  LINESTRING
#> dimension:      XY
#> bbox:           xmin: 142.7675 ymin: -35.06905 xmax: 143.324 ymax: -35.04559
#> CRS:            4283
#> # A tibble: 6 x 16
#>   id       PFI    UFI FEATURE_TYPE_CO~ NAME  NAMED_FEATURE_ID ORIGIN
#>   <chr>  <int>  <int> <chr>            <chr> <chr>            <chr> 
#> 1 VMHY~ 8.55e6 2.55e6 watercourse_cha~ <NA>  <NA>             2     
#> 2 VMHY~ 8.55e6 2.55e6 watercourse_cha~ <NA>  <NA>             2     
#> 3 VMHY~ 8.55e6 2.55e6 watercourse_cha~ <NA>  <NA>             2     
#> 4 VMHY~ 8.55e6 2.55e6 watercourse_cha~ <NA>  <NA>             2     
#> 5 VMHY~ 8.55e6 2.55e6 watercourse_cha~ <NA>  <NA>             2     
#> 6 VMHY~ 8.55e6 2.55e6 watercourse_cha~ <NA>  <NA>             2     
#> # ... with 9 more variables: CONSTRUCTION <chr>, USAGE <chr>, HIERARCHY <chr>,
#> #   FEATURE_QUALITY_ID <int>, CREATE_DATE_PFI <dttm>, SUPERCEDED_PFI <chr>,
#> #   CREATE_DATE_UFI <dttm>, OBJECTID <int>, geometry <LINESTRING [°]>

# Build a more specific query and collect the results
vicmap_query(layer = "datavic:VMHYDRO_WATERCOURSE_DRAIN") %>% # layer to query
  filter(HIERARCHY == "L") %>% # simple filter for a column
  filter(INTERSECTS(melbourne)) %>% # more advanced geometric filter
  select(HIERARCHY, PFI) %>% 
  collect()
#> The object is too large to perform exact spatial operations using VicmapR. 
#>             To simplify the polygon, sf::st_simplify() was used to reduce the size of the queryFALSE
#> Warning in sf_text(x): GDAL > 3.0.0 is required
#> Simple feature collection with 0 features and 0 fields
#> bbox:           xmin: NA ymin: NA xmax: NA ymax: NA
#> CRS:            4326
#> # A tibble: 0 x 1
#> # ... with 1 variable: geometry <GEOMETRY [°]>

Using other WFS urls

Using options(vicmap.base_url) VicmapR can query data from other WFS services; while this remains somewhat untested it is relatively easy to point VicmapR to another WFS url. This option would need to be set every session to override the base VicmapR url. For instance, the BOM WFS can be used as follows:

# set the new base url
options(vicmap.base_url = "http://geofabric.bom.gov.au/simplefeatures/ahgf_shcatch/wfs")

# list available data
listLayers()

# collect a data sample
catchments <- vicmap_query("ahgf_shcatch:AHGFCatchment") %>% 
  head(10) %>% 
  collect()

str(catchments)

adam-gruer / VicmapR