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Assessing the Relationship Between Habitat and Biological Communities in Virginia Streams Using Relative Bed Stability
Lawrence D. Willis , Jason R. Hill, Richard D. Miller, Mary R. Dail and George J. Devlin.
In 2001, the Virginia Department of Environmental Quality (VDEQ) started a project to assess the utility of a probability-based monitoring program (ProbMon) as an addition to existing targeted and watershed based water quality monitoring programs. ProbMon was initiated to determine the extent of water quality problems with statistical accuracy and to test new water quality monitoring and assessment tools. Anthropogenic sedimentation is recognized as a leading cause of water quality degradation; however, separating natural condition versus excessive anthropogenic sedimentation is difficult. USEPA’s Relative Bed Stability (RBS) index allows for the evaluation of human activities in stream bed sedimentation by calculating the natural streambed particle size. VDEQ examined RBS, benthic macroinvertebrate, rapid bioassessment habitat, and land cover data at 138 probabilistic stations. VDEQ found the RBS index was able to distinguish between streams with substantial riparian and basin disturbance and those streams that were in approximate balance between sediment supply and transport. VDEQ identified relationships where biological communities were impacted due to excessive sedimentation. RBS has potential value in state monitoring and assessment programs.