watershed soils LEGEND channel sediment watershed land cover

watershed soils LEGEND channel sediment watershed land cover alteration human activity streambank sediment ↑ water velocity & discharge riparian land cover alteration point source discharges channel alteration upstream impoundment source ↑ watershed erosion additional step in causal pathway ↓ water velocity & discharge ↑ sediment delivery to stream interacting stressor ↑ streambank erosion ↓ deposition on floodplain ↓ deposition ↑ sediment in discharged waters proximate stressor mode of action ↓ sediment delivery to stream ↑ deposition ↑ mobilization of bank & channel sediment ↓ availability of bank & channel sediment ↓ sediment in discharged waters biotic response Δ sediment in stream ↑ suspended sediments Δ filter-feeding efficiency ↑ deposited & bedded sediments ↑ coverage by fines ↓ interstitial spaces ↑ burial ↓ interstitial habitat & flow insufficient sediments ↓ substrate size ↓ light ↑ abrasion ↓ visibility ↑ heat absorption ↓ plants or biofilm Simple conceptual model diagram for SEDIMENT ↑ fine substrate habitats ↑ pool in-filling ↓ substrate diversity & stability ↑ sediment oxygen demand biologically impaired invertebrate assemblages Developed 7/2007 by Kate Schofield & Susan Cormier; modified 7/2010 biologically impaired fish assemblages other biological impairments ↓ habitat