DREAMS OF STREAM VIEWS- 3D RIVERSCAPES USING TERRESTRIAL LIDAR

With the advent of revolutionary technologies in river science such as terrestrial LiDAR, airborne LiDAR, structure from motion, drone based imaging, and radar based imaging etc., rivers can be surveyed with longitudinal continuity at a much higher spatial precision with temporal repetitions. Therefore, many scholars have proposed a continuous high resolution mapping of rivers commonly known as riverscapes. Aerial vehicles to map riverscapes have been successfully used in different locations. However, canopy cover along stream banks makes it difficult to image stream banks at high resolution especially in case of low order streams. Therefore, this paper extends that approach to the terrestrial level i.e. surveying the continuous riverscapes using terrestrial Lidar from the river bed instead of an aerial platform. It involved a continuous 3d scanning of the main stem of two low order streams using a terrestrial LiDAR. The process of scanning included the capturing of both point cloud and 260 othroimages at each scan site in the downstream direction. The individual scans were registered with the help of Leica Cyclone Software Suite as one continuous point cloud of the streamscape for each stream. The data on channel morphology was extracted by creating transects at a uniform interval of 10m along each streamscape. While providing an extremely large sample size, this approach allows us to analyze stream bank and bed profiles at much higher resolution for an overall analysis of the system without any canopy interference. The continuous point cloud of the streamscape also allows use to estimate the channel change over time at high spatial resolution. The future work will focus on quantifying the variability within as well as among different streams using high resolution data generated by this approach.

Keywords: River, mapping, survey, terrestrial LiDAR