HR: 16:45h
AN: B44B-06    [Abstracts]
TI: Spatial Hydraulic Metrics: Linking Channel Morphology, Flow Complexity and Stream Habitat
AU: * Crowder, D W
EM: crowderd@sws.uiuc.edu
AF: Illinois State Water Survey, 2204 Griffith Drive, Champaign, IL 61822
AU: Diplas, P
EM: pdiplas@vt.edu
AF: Virginia Tech, Department of Civil and Environmental Engineering (0105), Blacksburg, VA 24061
AB: Channel morphology is driven by a complex interaction between a watershed's hydrologic regime, geographic features, and sediment transport processes. Moreover, the geomorphic characteristics of streams may vary within different watersheds as well as along the stream itself. Individual morphologic features such as channel meanders, bars, pool-riffle sequences, as well as exposed rocks/outcrops in turn create numerous and varied types of flow complexity within channels. Evidence suggests that flow complexity is an important component of habitat for various aquatic organisms. Existing methods of quantifying hydraulic habitat typically rely upon one-dimensional hydraulic models to quantify the depths and velocities throughout a channel reach. Whereupon, point metrics (e.g. depth and velocity) are then used to determine the locations and amount of suitable hydraulic habitat within the stream reach. Such an approach is not capable of accurately reproducing flow complexity and assumes that two locations having similar depth and velocity values are equally suitable/unsuitable habitat, regardless of the flow conditions surrounding those two points. Methods for quantifying geomorphic features, the flow features they create, and the aquatic organisms using/preferring these habitats are needed to guide watershed/stream restoration projects. A conceptual model for quantifying how the flow features created by geomorphic features influence the amount and quality of habitat within a stream is presented. Specifically, it is proposed that after conducting a detailed survey of a channel reach, a multi-dimensional (2- or 3-dimensional) hydraulic model can be employed to model the hydraulic habitat (including flow complexities of biological importance). Spatial hydraulic metrics are then utilized to quantify flow complexity within the stream. Examples of implementing two-dimensional hydraulic models and spatial hydraulic metrics to model flow complexity within two-stream reaches are provided.
DE: 0400 Biogeosciences
DE: 1625 Geomorphology and weathering (1824, 1886)
DE: 1815 Erosion and sedimentation
DE: 1860 Runoff and streamflow
SC: Biogeosciences [B]
MN: 2005 Joint Assembly