Airborne laser scanning and radar interferometry for digital topographic modelling and flood risk assessment

Graz

Universität Graz

2007

7 Abb., 2 Tab., 14 Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

13342

200151965

Digital terrain and elevation models (DTM/DEMs) derived from Light Detection and Ranging (LiDAR) and interferometric synthetic aperture radar (InSAR) sensors can be used to provide 2D spatial information and 3D reconstruction of landscapes and objects (including buildings and vegetation). These data can subsequently be used to assess, for example, erosion risk, perform landslide and flood risk modelling, and simulate the effects of natural disaster events. In this study, baseline topographic and associated spatial data were generated using data captured by an airborne laser scanner (ALS) and archive interferometric SAR data for a section of the Wollongong coastline in SE Australia. Typical height accuracy of ~0.2 m was achieved using the ALS data, with declining accuracy in steep terrain or that covered in dense forest, whilst only moderate accuracies (13 - 27 m) were achieved using repeat-pass interferometery, given the high sensitivity to variation in terrain. The integration of the two led to localized improvements in topographic feature definition in the InSAR DEM. Additional topographic products were generated and assisted in establishing flood risk in the area and in simulating the effects of flooding and landslide scenarios. The study resulted in the refinement of methods for height estimation over diverse terrain and establishment of consistent techniques for data integration and scaling up from fine (micro-scale) to moderate (macro-scale) spatial resolution.