As part of several habitat restoration projects within the IMW, large pieces of wood have been placed in the river channel and floodplain. These wood placements are designed to create fish habitat by capturing spawning gravels, creating pools, and by providing cover where fish can hide and rest. IMW researchers from the University of Oregon are studying these large wood structures using an innovative remote sensing technique.
Patricia McDowell and her students are creating digital elevation models of the river substrate where these large wood structures have been added. Every few years they return to the same sites and do detailed topographic surveys of the channel bed and banks around each log structure. By comparing the digital elevation models from different years, they detect channel erosion and aggradation, shifts in bank structure, depths of pools, and development of gravel bars.
This research has been underway since 2008. Data collected in 2013 is currently being analyzed. After several years of measuring the same sites they will be able to determine the effectiveness of large wood placement for restoring fish habitat.
More information about this research can be found in the following presentation: “Monitoring Effectiveness of Log Structures” given by Patricia McDowell at the 2012 River Restoration Northwest Symposium
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