HR: 0800h
AN: H11F-0350    [Abstracts]
TI: Geomorphology Toolbox for Assessing the Potential Effects of Land-use Change and Management Practices on Stream Form and Integrity
AU: * Raff, D A
EM: draff@do.usbr.gov
AF: United States Bureau of Reclamation, D-8530 PO BOX 25007, Denver, CO 80225 United States
AU: Bledsoe, B P
EM: bbledsoe@engr.colostate.edu
AF: Colorado State University, Department of Civil Engineering Engineering Research Center, Ft. Collins, CO 80523 United States
AB: An important contribution that engineers and geomorphologists can make to environmental management is to develop techniques that empower non-specialists to make rational planning decisions within the context of a changing environment. Existing models can be used to assess the potential hydrologic effects of land-use change on receiving waters, but practical tools for translating these results into predictions regarding channel stability and effects on stream biota are currently unavailable to local planners. To improve watershed management in the context of changing land uses, we present a flexible, changeable package of mechanistic and statistical models to provide estimates of long-term changes in stream erosion potential, channel processes, and instream disturbance regime. These models are developed in Visual Basic for Applications/ Excel and contains a suite of stream / land-use management modules that are designed to operate with either continuous or single-event hydrologic input in a variety of formats. Based on input channel geometry and flow series, the various modules provide users with estimates of the following characteristics for pre- and post-land use change conditions: (1) the temporal distribution of hydraulic parameters including shear stress, specific stream power, and potential mobility of various particle sizes; (2) effective discharge / sediment yield; (3) potential changes in sediment transport and yield as a result of altered flow and sedimentation regimes; (4) frequency, depth, and duration of bed scour; (5) several geomorphically relevant hydrologic metrics relating to channel form, flow effectiveness and "flashiness". An attractive feature of this approach for stormwater management is a set of user-friendly tools to examine time-integrated sediment transport and scour characteristics across a range of flows and time periods associated with varying stormwater mitigation schemes. These modules give end users a suite of tools to compare the erosive potential of hydrographs, to depict channel changes that might result from different land-use management scenarios, and to improve interpretation of biomonitoring information through quantification of stream disturbance regimes.
DE: 1803 Anthropogenic effects
DE: 1815 Erosion and sedimentation
DE: 1824 Geomorphology (1625)
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting