Time-series analysis of rainforest clearing in Sabah, Borneo using Landsat imagery

Tropical forests are being cleared at alarming rates. The release of the Landsat image archive represents an opportunity to assess rainforest clearing over time through time-series analysis. The objective was to map the extent of rainforest clearing and assess land cover trends at the object level within a selected study area in Sabah, Borneo using Landsat images from 1991, 2000, 2004 and 2008. The images were delineated based on image interpretation cues and validated against existing high spatial resolution images on Google Earth. Overall mapping accuracies were >94%. Time-series trends for each delineated object were classified into trend classes to quantify the land cover history per object. The results showed that approximately 31% or 5,500 km2 of land cover within the study area changed between 1991 and 2008. This research presents an effective method for time-series analysis that can be used to regularly monitor forest clearing on Borneo.