Thomas Tracy, F&W Forestry Services, Inc., thomas.wesley.tracy@gmail.com (Presenter)
Adam Kaeser, U. S. Fish and Wildlife Service, Adam_kaeser@fws.gov
Thom Litts, Georgia Department of Natural Resources, thom.litts@dnr.state.ga.us


An accurate and efficient method for mapping river landscapes is needed by water resources professionals to support landscape-level management and research activities. We developed and evaluated an approach using the inexpensive Humminbird® Side Imaging sonar system and ESRI ArcGIS to produce high-resolution side-scan sonar image maps (SIMs). The SIMs were interpreted and used to map stream features including the bankfull channel boundary, benthic layers, and large woody debris. We were able to accurately inventory habitat features such as large woody debris (r2=0.79 for sonar estimates compared to actual wood counts) and substrates in both small and large rivers (overall classification accuracy of 77% and 84%, respectively) in southwest Georgia. In addition to providing estimates of stream habitat features comparable to traditional field assessments, side-scan sonar mapping reduces the time investment by 90%. By providing a means to incorporate river landscapes into traditional landscape studies, the sonar mapping technique allows us to fill in the gaps of our ecosystem monitoring and management programs. Thus, we now possess the potential to develop numerous applications that examine relationships between terrestrial ecosystems and aquatic ecosystems.