Assessing Image Processing Techniques for Mapping Landslides

A combination of high relief, steep slopes, intense rainfall, active tectonics and volcanic activity provide the conditioning and triggering for frequent and widespread landsliding events in New Zealand. While many techniques are available to map the extent of landslides, remote sensing and image processing methods have yet to be comprehensively evaluated. This study shows that manual interpretation of high resolution imagery is the most accurate method (92%) although also the most time consuming. NDVI thresholding and supervised classification (spectral angle mapper) provide an adequate accuracy level (76%) with considerable time saving for large area analysis.