Mapping River Bathymetry With a Small Footprint Green LiDAR: Applications and Challenges¹

TLDR

Airborne bathymetric LiDAR, originally developed for coastal and marine surveys, is increasingly applied to high‑resolution mapping of fluvial systems. The study aims to assess the suitability and accuracy of the USGS EAARL system for riverine mapping by comparing it with detailed wading and sonar surveys. Researchers compared river‑bed topographies and laser waveforms from the EAARL system with conventional surveys across the Trinity, Klamath, and Colorado Rivers, analyzing water and substrate characteristics and processing algorithms. Results show that environmental conditions and post‑processing algorithms significantly affect EAARL accuracy, leading to mapping errors that can compromise hydraulic modeling and habitat assessments.

Abstract

Kinzel, Paul J., Carl J. Legleiter, and Jonathan M. Nelson, 2012. Mapping River Bathymetry with a Small Footprint Green LiDAR: Applications and Challenges. Journal of the American Water Resources Association (JAWRA) 1‐22. DOI: 10.1111/jawr.12008 Abstract: Airborne bathymetric Light Detection And Ranging (LiDAR) systems designed for coastal and marine surveys are increasingly sought after for high‐resolution mapping of fluvial systems. To evaluate the potential utility of bathymetric LiDAR for applications of this kind, we compared detailed surveys collected using wading and sonar techniques with measurements from the United States Geological Survey’s hybrid topographic/bathymetric Experimental Advanced Airborne Research LiDAR (EAARL). These comparisons, based upon data collected from the Trinity and Klamath Rivers, California, and the Colorado River, Colorado, demonstrated that environmental conditions and postprocessing algorithms can influence the accuracy and utility of these surveys and must be given consideration. These factors can lead to mapping errors that can have a direct bearing on derivative analyses such as hydraulic modeling and habitat assessment. We discuss the water and substrate characteristics of the sites, compare the conventional and remotely sensed river‐bed topographies, and investigate the laser waveforms reflected from submerged targets to provide an evaluation as to the suitability and accuracy of the EAARL system and associated processing algorithms for riverine mapping applications.