Geomorphic Change Detection: Harnessing Repeat High Resolution Topography
2013 Fall Cyberseminar Series
- Joseph Wheaton / Utah State University
Recent advances in topographic surveying technologies have given rise to a slew of new survey methods: Terrestrial Laser Scanning (TLS), Multi-beam SONAR (MBS), Structure from Motion (SFM), and Airborne Laser Scanning (ALS), and the improved efficiency of traditional methods like photogrammetry, rtkGPS and robotic total station surveys. Each of these enables the rapid acquisition of high resolution point cloud data sets. The potential utility of these topographic point clouds for the purpose of quantifying geomorphic process rates and geomorphic change detection is exciting but the reliability of such estimates are dependent upon the environmental conditions they were acquired in as well as the user’s ability to effectively filter the point clouds, efficiently manage the memory intensive files, quantify the uncertainty in the topographic representation, and convert the point clouds to data formats in which relevant analysis can be performed and presented from. Two basic approaches to change detection exist, one relies on cloud-to-cloud differencing and the other on surface-to-surface differencing. A variety of techniques and software packages exist to undertake these analyses, each with their own advantages and disadvantages. This presentation seeks to highlight recent methodological advances and software that enable geomorphic change detection studies. Specific attention is given to the comparison of raster based surface-to-surface differencing that leverages the power of the high resolution point cloud. I will highlight some examples of how geomorphic change detection is being used to address fundamental scientific questions about the evolution of rivers and creation, maintenance and destruction of fluvial habitats. I will conclude with a plea to the next generation of researchers to push past the methods and harness these data sets to push our science further.