State Veg Maps 2021

Table of Contents

• Introduction
• Data source
  • Overlaps
• Infrastructure and Configuration
• Output
• Loading
• Cleanup the geometry
• Make one table / layer of State Veg Maps
• Delete the redundant tables
• Do some QA

Create a single aggregated layer/table of NSW State Veg / PCT Maps from the datasets available in 2021.

Introduction

The NSW State Veg Maps (SVMs) refer to Plant Community Types (PCTs) and are a foundation for Biodiversity Credits and the Offset Trading Groups within that. Biodiversity is increasing in importance and so has the requirement to be working seamlessly across all of the maps.

The individual SVMs sometimes overlap and appear to have been built with slightly different methodologies. Therefore the order in which they are clipped and aggregated affects the output. There are also variations in the naming of attributes.

There is advice that the authors of the data will provide an update on the east and create a seamless layer in March 2022. It appears that Central and West NSW are not being updated by the new eastern update. Therefore expecting the bulk of this workflow will endure (to do is the incorporation of the eastern update approx Mar 2022).

This dataset can be a mouthful for Postgres and Postgis if there are any errors, so a very verbose method of processing is followed. Possibly this is due to geometry anomalies in the Central Tablelands input table, amongst others.

Special note, there is a hole with no coverage at Euchareena, which can be a loose end when troubleshooting the arrangement of layers…​

Stellar support has been provided by the CrunchyData team as part of the normal use of their CrunchyBridge service. https://www.crunchybridge.com

Image courtesy of NSW DPIE

Home of this doc https://github.com/billjwilliamson/state_veg_maps

Data source

Please refer to NSW Department of Planning Industry and Environment for updates of the source data. Landing page https://www.environment.nsw.gov.au/topics/animals-and-plants/biodiversity/nsw-bionet/about-bionet-vegetation-classification/vegetation-maps/state-vegetation-type-map

Layers used in this workflow;

Region	File	Layer
Western NSW	Vegetation_Western_SVTM_v1_0_4492/data/quickview.gdb	WesternSVM_v1_0_PCT_E_4492
Sydney Metro	vegetationsydmetroareav314489/data/GDB/data.gdb	SydneyMetroArea_v3_1_2016_E_4489
Upper Hunter	vegetationhunteruppersvtm4894/hunterupper_svtm_4894/data/quickview.gdb	HunterUpperSVM_v1_0_PCT_E_4894
Central Tablelands	Vegetation_CentralTablelands_SVTM_4778/data/VegMap.gdb	CentTableSVM_v1p0_PCT_E_4778
Border Rivers Gwydir Namoi	Vegetation_BorderRiversGwydirNamoi_4467/data/GDB/QuickViewMap.gdb	BRG_NamoiSVM_v1p3_PCT_E_4467
Riverina	vegetationsvtmriverinav1.2quickviews4469/SVTM_Riverina_v1p2.gdb	Riverina_v1p2_Quickview
Central West & Lachlan	vegetationcentwestlachlansvm4468/Vegetation_CentWestLachlanSVM_4468/data/VegData.gdb	CentWestLachSVM_v1p4_PCT_E_4468

Overlaps

The layers are not necessarily clipped against one another. They are can be adjacent but may or may not overlap. The table below indicates overlap and therefore appropriate processing.

Y = Overlap

	Order of processing	Western NSW	Sydney Metro	Upper Hunter	Central Tablelands	Border Rivers Gwydir Namoi	Riverina	Central West & Lachlan
Western NSW	3	X	.	.	.	.	.	.
Sydney Metro	2	N	X	.	.	.	.	.
Upper Hunter	6	N	N	X	.	.	.	.
Central Tablelands	1	N	N	Y	X	.	.	.
Border Rivers Gwydir Namoi	4	N	N	Y	N	X	.	.
Riverina	7	N	N	N	Y	N	X	.
Central West & Lachlan	5	Y	N	N	Y	N	Y	X

Overlapping layers must have a mask created and are then clipped against that mask.

Infrastructure and Configuration

• Resources: 32 GB / 4 cores — 250 GB

• Provider: CrunchyBridge on aws

• Region: ap-southeast-2

SELECT current_database(), version(), PostGIS_version(),
 PostGIS_GEOS_version()
;

"terroir"	"PostgreSQL 14.1 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-4), 64-bit"	"3.1 USE_GEOS=1 USE_PROJ=1 USE_STATS=1"	"3.9.1dev-CAPI-1.14.1"

alter system set work_mem = '64MB'
;

Output

• Size on disk is 16 GB with 12.8 million records

• Geometry: Polygon (MultiPolygon)

• Extent: -84969,5926055 : 1021976,6838874

• EPSG: 7855

Loading

Import to the db

GDAL commands via QGIS configure_01_v.state_veg_map_2021.sh

Cleanup the geometry

Make the geometry valid - GitHub Link configure_02_v.state_veg_map_2021.sql

Make one table / layer of State Veg Maps

Make one table - GitHub Link configure_03_v.state_veg_map_2021.sql

Delete the redundant tables

clean up cleanup_51_v.state_veg_map_2021.sql

Do some QA

Do a calculation of area grouped by the formation then again by the mapsource, as a test.

query to calculate area as qa on the job qa_41_v.state_veg_map_2021.sql

qa results by formation state_veg_maps_2021_qa_area_by_formation.csv

qa results by mapsource state_veg_maps_2021_qa_area_by_mapsource.csv

END