Give Me the Dirt: Detection of Gully Extent and Volume Using High-Resolution Lidar

摘要: The Fitzroy catchment drains into the Great Barrier Reef lagoon. It is largest on east coast of Australia, with an area over 140,000 km2. To ascertain point-sources erosion, and to quantify volume sediment lost from gullies, within a major challenge for land-management; despite this, gully locations volumes have never been thoroughly investigated. This study aims develop semi-automated method detect map extent volume, using aircraft-mounted Light Detection Ranging (LiDAR) technology catchment. Twenty LiDAR transects were acquired in 2007 (5000 × 275 m). average distance between points data was 0.3 m ground, height accuracy 0.1 m. Digital Elevation Models derived transects, 0.5-m spatial resolution. We delineated gullies terrain attributes backscatter intensity returns. Transects classified as ‘gully’ or ‘non-gully’ objected-oriented classification. Gully estimated each pixel twenty transects. For four we used random forest algorithm model relation presence set readily available ancillary variables. also modelled These models predict at unsampled locations. considered extrapolation success. products generated this will be inform water-quality models, asses land condition, improve our understanding dynamics erosion under different climate land-management regimes.