SLATS methodology

Since the 1990s and up to 2018, the SLATS monitored woody vegetation loss due to human-induced land clearing, applying a methodology that used Landsat satellite imagery and a combination of automated image classification, desktop analysis and field methods.

In recent years, significant scientific enhancements were made to SLATS to provide a more comprehensive monitoring and reporting framework for the state. The revision incorporated the latest satellite and computing technologies and contemporary science. It also considered current and future data and information requirements.

Due to these changes to the SLATS methodology, previous SLATS reporting up to and including the 2017–18 SLATS report is not comparable with any reporting after that date.

The current SLATS methodology includes:

• maintaining a detailed map of the extent of Queensland’s woody vegetation for ongoing monitoring, reporting and accounting
• using Sentinel-2 satellite imagery as the primary information source to detect and map clearing activity and new regrowth
• methods for estimating woody vegetation density (i.e. foliage projective cover) and the age of the woody vegetation (since its last major disturbance).

In addition, the 2022-23 SLATS report introduces information about the height of vegetation for areas affected by clearing activity based on data from the global canopy height data set published by Lang et al. (2023). This is a 10m spatial resolution estimate of canopy height, based on a model relating Sentinel-2 reflectance to vegetation height data from the space-borne LiDAR from the Global Ecosystem Dynamics Investigation (or GEDI) mission. A preliminary assessment of these data was undertaken to assess the model’s performance for Queensland, using Queensland-based LiDAR data. This found that the accuracy was acceptable for the purpose of summarising SLATS clearing activity data by broad height categories. Improving on this data set for better height attribution for Queensland’s woody vegetation is a focus of current SLATS research efforts.

SLATS primarily aims to monitor native woody vegetation. However, due to the difficulty of differentiating between native and non-native woody vegetation using satellite imagery, non-native woody vegetation change is also included. This may include exotic pine plantations, orchards or invasive exotic woody weeds.

For details about the current SLATS methodology, refer to Statewide Landcover and Trees Study – Methodology overview v1.3 (PDF, 1 MB) .

Reference: Lang, N., Jetz, W., Schindler, K. and Wegner, J.D. (2023). A high-resolution canopy height model of the Earth. Nature Ecology & Evolution, 7, 1778–1789. https://doi.org/10.1038/s41559-023-02206-6

Peer-reviewed science and continuous improvement

The current SLATS methodology and program enhancements were the subject of a comprehensive independent peer review in 2021. The review was led by CSIRO and included experts in remote sensing, ecology, and natural resource management.

The review considered the science underpinning the program and its effectiveness in supporting environment and natural resource information requirements. It found that the methods were appropriate and consistent with best practice scientific reporting, and that the program would have ongoing impact for environmental and natural resource management in Queensland.

SLATS research is focussed on improving efficiencies and enhancing the SLATS product suite, and improving reporting. This ongoing work is a collaboration with the Joint Remote Sensing Research Program partners, and includes:

• investigating options for improved reporting and new ways to access to SLATS information
• improving SLATS change detection using new machine learning techniques
• improving foliage density measures using LiDAR data
• further developing methods for improved estimation of woody vegetation height, structure, and trends, particularly for application in Queensland’s unique woody ecosystems.

More information

• Current SLATS reports—view current SLATS reports.
• Current SLATS data products—view and access the current series of SLATS data.
• Previous SLATS data and reports—view and access Previous SLATS data, reports and publications.

Contact

• For general SLATS enquiries, email SLATS_enquiries@detsi.qld.gov.au.
• Find more information about the Joint Remote Sensing Research Program.
• Contact the Department of Natural Resources and Mines, Manufacturing, and Regional and Rural Development for enquiries about vegetation management in Queensland.