Type of Document Master's Thesis Author Hall, Karen URN etd-04252012-092756 Title Surface water flow resistance due to emergent wetland vegetation Degree Master of Engineering Department Biological Systems Engineering Advisory Committee
Advisor Name Title Thompson, Theresa Committee Chair Diplas, Panayiotis Committee Member Easton, Zachary Committee Member Keywords
- friction factor
Date of Defense 2012-04-11 Availability restricted AbstractThe key to a successful wetland design is duplicating the hydroperiod of the
desired wetland type. Dense wetland vegetation affects surface water flow rates
by increasing flow resistance. Prior research represented the vegetation as
individual stems; however, many wetland species grow in clumps. Therefore,
the objectives of this study were to investigate the effect of clumping
vegetation on flow resistance and to develop a prediction equation for use in
wetland design. A 6-m by 1-m by 0.4-m recirculating flume was planted with
mature common rush, Juncus effusus, a common emergent wetland plant. Three
different flow rates (3, 4, and 5 L/s) and three different tailgate heights (0, 2.5,
and 5 cm) were used to simulate a variety of wetland conditions. Plant spacing
and clump diameter were varied (20 and 25 cm, 8 and 12 cm, respectively).
Friction factors ranged from 9 to 40 and decreased with increasing plant
density. Non-dimensional parameters determined through Buckingham Pi
analysis were used in a regression analysis to develop a prediction model.
Results of the regression analysis showed that the fraction of vegetated
occupied area (P) was most significant factor in determining friction factor.
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