Surface water flow resistance due to emergent wetland vegetation
The 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. The...
| Main Author: | |
|---|---|
| Other Authors: | |
| Format: | Others |
| Published: |
Virginia Tech
2014
|
| Subjects: | |
| Online Access: | http://hdl.handle.net/10919/42242 http://scholar.lib.vt.edu/theses/available/etd-04252012-092756/ |
| Summary: | The 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. === Master of Science |
|---|