River Bed Characterization on the West Branch of the Susquehanna River with Side Scan Sonar

Elaine Langone Center, Terrace Room

Channel formation and maintenance processes for river form and habitat creation depend greatly on the ability of discharges to transport and distribute sediments of particular sizes. Commonly-used methods for sediment size determination (e.g. pebble counts and sample collection with a dredge device) have limitations for use in large river environments with substantial gravel- and cobble-sized bed sediment such as the West Branch of the Susquehanna River. Side scan sonar and photogrammetry methods are being used to conduct a large-scale characterization of bed material size and spatial distribution of sediments on the bed of the river. A 5-km reach of the West Branch of the Susquehanna River is identified as a test section for the application of the side scan sonar. A Lowrance® HDS-10 Gen2 system with StructureScan® is used to collect extensive sonar imagery of the bed of the river. The collected data are processed with the SonarTRX and ArcGIS software to develop a complete sonar image of the river bed. The characterization of river bed sediments and distribution patterns on a section of the West Branch of the Susquehanna River provides necessary data for the interpretation of channel formation due to modern floods and paleofloods in the region and for aquatic ecologists interested evaluating benthic habitat within the river.