2007 Annual Report
1a.Objectives (from AD-416)
The objective is to identify cost effective solutions for protecting levees of commercial aquaculture ponds and irrigation reservoirs from accelerated erosion by surface wave action in highly erodible soils of the Arkansas-Mississippi Delta.
1b.Approach (from AD-416)
ARS will utilize the hydraulic laboratory facilities of the ARS National Sedimentation Laboratory to construct a physical model of typical levees and conduct tests to research and document the effectiveness of various mechanical treatment alternatives that serve to dissipate wind-wave energy and are cost effective. The data from these tests will be analyzed and compared to the extent possible with performance data from field tests planned by scientists from the University of Arkansas at Pine Bluff.
This report serves to document research conducted under a Reimbursable Cooperative Agreement between ARS and the National Resources Conservation Service (NRCS). Additional details of research can be found in the report for the in-house project 6408-13000-017-00D, "Integrated Assessment and Analysis of Physical Landscape Processes that Impact the Management of Agricultural Watersheds." During FY 2007, laboratory experiments on floating wave barriers were continued. Extensive tests of many different geometries, mooring techniques, and levels of buoyancy were performed using the instrumented, automated wave flume constructed for this project. The resulting data were processed, yielding a preliminary best design consisting of a combination of plastic irrigation pipe sizes restrained by vertical pilings. This design was successfully field tested in Schafer Lake, near Carlisle, Arkansas. Visual observations of reduced wave heights were confirmed by measurements of wave height/energy that showed significant reductions. Monitoring was accomplished through regular email, telephone contact, and, when appropriate, site visits. At appropriate stages in the project, progress has been documented by the preparation of reports, conference proceeding papers, and journal articles.