Author(s): Kevin R. Hall; Jari T. Silander
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Keywords: No Keywords
Abstract: The size and number of coastal wetlands in the Great Lakes have been rapidly declining over the past century. Only in the past two decades, have people began to understand the complex environmental and biological benefits of these fresh water marshes. Recently, bioengineering techniques have been adapted as an integral functioning part of shore protection schemes. The bioengineering approach makes use of natural methods and materials, not only to provide suitable protection from wave action, but to enhance the environmental conditions at the site; primarily through habitat and species diversification. Constructed wetlands are prime examples of additions to shore protection schemes that provide ancillary benefits such as water quality improvements and provision of a buffer zone and a rich, biologically diverse sanctuary for terrestrial and aquatic species. The wetland plants, themselves, provide increased erosion resistance of the soil mass in which they are planted and can reduce the wave energy levels reaching the shoreline in their lee. The focus of most wetland studies has been related to biological aspects and to a lesser degree, to their hydrology. Little research has been conducted from a coastal science and engineering perspective, especially with regard to wave exposed shoreline vegetation. This paper describes a recent study undertaken to examine common Great Lakes emergent shoreline aquatic plants in order to assess their applicability for use in a bio-engineered shore protection scheme. The study consisted of both field investigations and two dimensional physical hydraulic model studies. Field measurements included evaluating wave attenuation capabilities and conducting pull out strength tests. Laboratory tests were completed to evaluate the wave attenuation characteristics of several species subject to variations in plant density, plant height, wave period, wave height and water depth.
Year: 1997