Abul Baki, a professor of civil and environmental engineering and Amir Golpira, a civil and environmental engineering Ph.D. candidate at Clarkson University and their co-authors recently published their research on the effects of boulder placement on hydraulic metrics of instream habitat complexity in the prestigious journal Nature Scientific Reports. Scientific Reports is the 5th most-cited journal in the world, with more than 696,000 citations in 2021, and receives widespread attention in policy documents and the media.
Numerous instream habitats throughout the world have been degraded due to factors such as sediment load changes, stream fragmentation (connectivity loss), and stream channelization (simplification). Restoring degraded streams by enhancing habitat complexity has been one of the primary objectives of river restoration projects in recent decades.
Boulder placement is a common method to restore degraded instream habitats by enhancing habitat complexity. This experimental study is the foremost attempt to systematically investigate the influence of rock-ramp boulder placement with varying boulder concentration and flow rate on habitat hydraulic complexity metrics. A set of relationships were proposed to predict the metrics in reaches with boulders, and it was found that boulder placement especially at higher concentrations may provide suitable habitats for several riverine fish species.
“Our findings may benefit restoration projects that use the boulder placement technique to ecologically restore degraded streams and facilitate the application of habitat metrics, as a reliable measure of habitat complexity in future work. Further field and experimental studies are needed to establish a reliable linkage between the metrics and instream species and to test a wider variety of parameters. Currently, in the Ecohydraulics Lab at CU we are undertaking various experiments to better understand flow hydrodynamics and its subsequent effects on instream habitat in boulder-bed reaches,” Dr. Baki said.
To learn more about the study, visit https://www.nature.com/articles/s41598-022-17281-1