Evaluation of the change in physical features of two over-wide channel stream relocation projects
Loading...
Date
2007-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
The Ohio State University
Abstract
The over-wide channel design is a recent, innovative, channel modification design. In this design, the channel is constructed as a wide, flat trapezoid at the channel bed elevation. The theory behind the design states that over time, floodplain benches will form, creating a stable two-staged geometry with a functional floodplain. This design could function as a stormwater management practice designed to provide flood storage and channel protection. This study begins the process of gathering data to create a database to (1) evaluate whether following construction the evolution of over-wide channels is consistent with theory; and (2) if the channel does evolve according to theory, to initiate the work necessary to determine how quickly it will take for an over-wide channel to evolve into a two-stage system. The parameters examined in this paper are geomorphology, turbidity, and sequential photographs. This study examined two study sites; Clover Groff Run and a tributary to Big Walnut Creek. While little change was observed at the Clover Groff Run site, the formation of a small inset channel and attached floodplain system was observed at the Big Walnut Creek study site. This channel was 8 feet wide and 0.75 feet; within the predicted range of the design. While aggradation and down-cutting were both observed at the study site, the measured inset channel was formed predominantly by down-cutting. Future studies are needed to definitively quantify the evolution of over-wide channels.
Advisor: Andrew D. Ward
Description
Keywords
over-wide channel, two-stage channel, stream protection, stormwater management, floodplain formation