Two large tropical cyclones struck Taiwan in the summer of 2004 and landslides triggered by these events caused not only casualties and housing damage but also produced large volumes of sediment that entered rivers and reservoirs. For reservoir and watershed management it is important to quickly identify the location and areal extent of new landslides for coordinating mitigation efforts. In this study, two automated methods, supervised and unsupervised classification of 10m multi-spectral SPOT-5 imagery, were tested for their ability to identify and
map landslide areas before and after the two storm events. A slope map was applied to mask roads, riverbeds and agricultural fields erroneously commissioned as landslides. The automated classification results were compared with manually delineated landslides using SPOT-5 supermode satellite imagery with a resolution of 2.5 m. Statistical testing and spatial analysis of the mapping results were performed. Finally, the results from all three methods were validated by using 0.35m orthophotographs. This paper reports the results and discusses the salient differences between the automated and manual methods.
Borghuis, A. M., Chang, K., & Lee, H. Y. (2007). Comparison between automated and manual mapping of typhoon‐triggered landslides from SPOT‐5 imagery. International Journal of Remote Sensing, 28(8), 1843-1856.
