QUANTIFYING STREAM BED ROUGHNESS USING TERRESTRIAL LIDAR

Stream bed roughness plays an important role in fluvial processes. While affecting the flow and movement of bed load, it also plays important ecological functions. This paper presents a detailed methodology to quantify stream bed roughness which could be used for the management of fresh water systems in different locales. A low order alluvial channel, Klingle Creek was scanned in the downstream direction from headwater to mouth using Leica C10 laser scanner. At each scan site, a 3d point cloud was generated at the medium resolution (0.1m horizontal spacing and 0.1m vertical spacing). The point cloud data was processed using the Leica Cyclone Suite. It involved creating longitudinal transects at the bankfull stage in the sections where the stream bed was visible. Each transect was converted into a TIN mesh followed by classifying it into a grid of 10mm² cells. The coordinates of individual cells for each transect were used to estimate the bed roughness.

Keywords: Stream, bed roughness, fluvial, water