NGIS’ Dr Zahurul Islam and six NGIS remote sensing specialists are using Landsat satellite imagery and standardised methodology developed by the AGO and CSIRO to map forest extent at 25m resolution for time slices 1972 to 2004.
In total, the AGO Land Cover Change Project determines land cover change over approximately 7.5 million square kilometers.
An automated process (known as thresholding) is used to determine the extent of forest in a selected area. The amount of forest in each 25m pixel is calculated for each time period by comparing the spectral index in the Landsat image with the reference index for that zone.
NGIS Managing Director, Paul Farrell, “NGIS is proud to be part of a project that will help protect environmental standards in Australia for generations to come”.
AGO project background
In 1992 the United Nations Framework Convention on Climate Change (UNFCCC) brought together countries around the world in agreement to work together to reduce the impact industrialisation, specifically greenhouse gas emissions, has on the climate.
The Australian government responded to the requirements of the UNFCCC and the later Kyoto Protocol by initiating the National Carbon Accounting System (NCAS) governed by the Australian Greenhouse Office.
The UNFCCC requires Australia produce an annual inventory of national greenhouse gas emissions. Inventories are conducted annually, covering the period from 1990 onwards and detail human-induced greenhouse gas emissions by sources and removal of sinks.
Land based sources and ‘sinks’ (sinks are forests and other vegetation which through photosynthesis remove carbon dioxide) play an important role in Australia’s greenhouse emission profile. The AGO estimates that 30% of Australia’s human-induced greenhouse gas emissions result directly from farming and agricultural activities including cropping, grazing and deforestation.
Land use change
The ability to accurately report levels of carbon across land systems requires knowledge and historical data on:
- plant growth and life cycle
- soils
- land cover change
- land use management
- climate.
NGIS assists the AGO in mapping landscape change through the analysis of hundreds of satellite images in multiple time slices over the last 30 years.
Assessing the amount of forest cleared for agriculture and other ‘human related’ activities will assist the AGO in accurate carbon change modelling for greenhouse gas emission budgeting.
Another outcome of the project is the production of the year 2004 Landsat 5 TM mosaic of Australia. Imagery is accessible from the GeoScience Australia web site via the ACRES on-line ordering system.
For further information on the AGO Land Cover Change Project, please contact NGIS on 08 9355 2444.