|Shields Jr, Fletcher|
Submitted to: Journal of the American Water Resources Association
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2008
Publication Date: 6/1/2008
Citation: Simon, A., Doyle, M., Kondolf, M., Shields Jr, F.D., Rhoads, B., Mcphillips, M. 2008. Reply to Discussion by Dave Rosgen of Critical Evaluation of How the Rosgen Classification and Associated "Natural Channel Design" Methods Fail to Integrate and Quantify Fluvial Processes and Channel Response?. Journal of the American Water Resources Association, 44(3): 793-802. Interpretive Summary: While there are several reasons for limiting the use of classifications in restoration design, there are equally important reasons for maximizing the use of physically-based analyses. The foremost advantage of the process-based approach is that it is well established in the scientific and engineering literature. For decades, geomorphologists and hydraulic engineers have been quantifying river processes and developing models that have been tested and refined over time. Developing a design using this rich literature leverages off of a substantial scientific background, and thus provides a critical foundation from which to defend the design approach. Such literature and historical precedence is lacking for the classification approach. The physics of erosion, transport, and deposition are the same regardless of the hydro-physiographic province or stream type because of the uniformity of physical laws. Channel adjustment is driven by the imbalance between driving and resisting forces, sediment supply and sediment-transporting capacity. Determining rates and magnitudes of adjustment, sediment-transport rates and ultimate channel forms are a matter of defining those spatially- and temporally-varying forces and variables.
Technical Abstract: The authors thank Dr. Rosgen for his lengthy discussion as it presents an opportunity for us to clarify and expand on some of the criticisms that are presented in the original manuscript as well as to differentiate between what Dr. Rosgen's Discussion presents as "facts" and what he terms the "opinions", and "untrue...irresponsible and inaccurate statements" made by Simon et al. (2007). Prior to publication Simon et al. (2007) went through an intensive 13-month peer-review process by three anonymous reviewers and an Associate Editor. It is unlikely that we and the reviewers were so "incorrent" about so many things. Certainly, we and the AWRA want to assure readers of this journal that this material is not an opinion piece, but is substantiated and fully supported by peer-reviewed, documented findings. These types of exchanges in the peer-reviewed literature are, however, welcome and are critical for the testing, validation, and advancement of science. It is important for the reader to bear in mind that neither Rosgen's discussion, nor our reply have gone through the peer-review process. Only the original Simon et al. (2007) paper has been peer reviewed.