Continental Monitoring: 34 Years of Land Cover Change Using Landsat Imagery

In Australia, remotely sensed Landsat data is routinely used for mapping and monitoring the change in extent of woody perennial vegetation. Time-series remotely sensed satellite imagery and ground information is used to form multi-temporal classifications of presence/absence of woody cover, typically for state-based management and reporting of clearing. More recently, there has been increased interest from landuse changes associated with agriculture and forestry being a significant component in Australia's carbon budget. To quantify the amount, the capability for continental monitoring of land cover changes using Landsat data has been developed through a collaboration between the Australian Greenhouse Office (AGO), the CSIRO, and other partners. The project, called the National Carbon Accounting Land Cover Change Project (NCAS-LCCP) uses some 5000 Landsat MSS, TM and ETM+ images to map the presence/absence of perennial vegetation at 25m resolution for fifteen time periods since 1972. The landsat based monitoring program is expanding to include monitoring of sparse woodland (5-20% canopy cover) and urban change to meet both carbon accounting and natural resource management needs. In this paper we describe our methodology, with a focus on the remote sensing algorithms and techniques we employ, and present results of forest change along with estimates of accuracy.