Using CSIRO’s Urban Monitor high resolution digital photography, vegetation height strata of endemic and exotic species has been calculated and reported as an area for each height strata of 0 – 3 m, 3 – 8 m, 8 – 15 m and 15+ m. The area of grass covered areas falling into the 0 – 50 cm range has also been calculated and recorded in square metres and percentage of total parcel area. Vegetation coverage greater than 3 metres in height has been deemed tree canopy. The canopies have been aggregated and reported as total canopy coverage in square metres, percentage of total parcel area and percentage range.
Parcels to be analysed were sourced from the 2016 Integrated Land Information Database (ILID) and supplied to CSIRO by the Department of Planning, Lands and Heritage. The results were assembled into Urban Forest features where the Urban Monitor coverage was complete and published for the following years: 2009, 2014, 2016, 2018.
Land parcels were assigned locational data (2016 ABS meshblocks, suburbs, local government authority (LGA) and planning sub-region) based on the parcel centroid. They were then attributed with the following land use categories:
• Street Block: residential, commercial, industrial, hospital/medical, educational, and some agricultural and transport land uses
• Parks: public parks, open space, private recreation grounds and State Forest
• Roads: roads including road reserves
• Other Infrastructure: rail, airports and utilities infrastructure
• Other: land uses in transition that have not progressed sufficiently to be Street Blocks or do not conform to urban form
• Rural: primary production land that does not fall in categories above
• Water: ocean and other waterways, including reservoirs
The vegetation height strata areas and total canopy coverage values were calculated for each land parcel, with percentage and range values based on total parcel area.
Some parcels have incomplete coverage or are excluded from Urban Forest in some years. When undertaking comparative analysis between years, especially at an aggregated level (higher than parcel level), a filter must be applied using the In[YEAR] field. Failure to filter may result in higher levels of change being reported. For example, if undertaking percentage change in total canopy coverage between 2009 and 2018 at a LGA level, apply a filter on the 2018 data of In2009 = Yes first before aggregating to LGA level. This removes all parcels that were not represented in the 2009 data and allows a like-for-like comparison.
NOTE: As locational attributes were populated based on the location of the parcel centroid, aggregating areas for larger administrative boundary units (Meshblock, Suburb, Local Government Authority or Sub-region) must be undertaken carefully as parcels sometimes cross boundaries. When calculating percentage cover for these boundaries, the total area based on the aggregated boundaries should be used, not the area based on the administrative boundary polygon.
