Raymond Schaffranek (retired); Virginia Cater (retired); Jonathan K. Lee (deceased)
Rybicki, Nancy B.; Reel, Justin T.; Ruhl, Henry A.; Stewart, David W.; Jones, John W.
Ruhl, Henry A.; Rybicki, Nancy B.; Reel, Justin T.; Gammon, Patricia T.
Reel, Justin T.; Rybicki, Nancy B.; Ruhl, Henry A.; Gammon, Patricia T.; Lee, Jonathan K.
Reel, J.; Ruhl, H. A.; Gammon, P. T.; Carter, V.; Lee, J. K.
Reel, Justin T.; Ruhl, Henry A.; Gammon, Patricia T.; Carter, Virginia
Reel, Justin T.; Ruhl, Henry A.; Gammon, Patricia T.; Carter, Virginia; Lee, Jonathan K.
Visser, H. M.; Jenter, H. L.; Duff, M. P.
Velocity-profile and vegetation data collected in the field in FY 1996 and FY 1997 at sites P33 and NESRS3 in the Everglades National Park were analyzed. Pipe-flow data collected at these sites in FY 1997 were analyzed, and water-surface slopes were obtained from the pipe-flow data. Field measurements were made in November 1997 in the Taylor Slough basin in the Everglades National Park to obtain information on the relation between flow and vegetation characteristics. Measurement of flow depth, flow velocity, and water-surface slope was necessary to evaluate flow resistance. Vegetation was sampled wherever hydraulic measurements were made. Approximately 20 hydraulic and 20 vegetation measurements were made during this field trip. An ADV was used to measure flow velocities, and the pipe manometer was used to obtain water-surface slopes.
In order to collect the data needed to evaluate and develop flow-resistance expressions, a unique pipe-manometer method was devised to determine the local water-surface slope in wetlands. The device is a 2.4-meter-long plastic pipe, 7.6 cm in diameter, with a 90-degree elbow at one end. The pipe was positioned in the water column parallel to the flow direction and an ADV meter equipped with a side-looking probe was used to measure the centerline flow velocity in the pipe. Knowing the flow characteristics of the pipe, the difference in the water-surface elevation at the ends of the pipe is calculated from appropriate expressions using the measured centerline flow velocity in the pipe. The pipe manometer is currently calibrated, and appears to hold great potential as an efficient, accurate method for the local measurement of the shallow water-surface slopes typical of the low-velocity, small-gradient flows in the Everglades.
The death of Dr. Jonathan Lee, the project chief, in December of 1999 prompted the need for development of new approaches to accomplish the project objectives. All project laboratory and field datasets collected over the four-year duration of the project (1996-1999) were organized and catalogued by project personnel during December of 1999 and January of 2000 and have been analyzed throughout the remainder of the year to yield velocity profiles, depth-averaged velocities and Manning’s n values. Data from the laboratory, Shark Slough, Taylor Slough and Water Conservation Area 2A have been analyzed and tabulated. Summary reports describing these data sets were prepared.
In the spring of 2000, contracts were initiated with Dr. Vincent Lai to complete the pipe manometer theoretical analysis and calibration and Dr. Lisa Roig to complete the vegetative resistance calculations for both laboratory and field data.
All data pertaining to the calibration of the pipe manometer were processed during January and February of 2000. The data were turned over to Lai for evaluation in March 2000. In turn, Lai has provided the Project Chiefs with a draft report describing the theory of the pipe manometer, including definition of the limits of laminar, transitional and turbulent flow theory.
At the end of March, Roig initiated a literature review on the subject of vegetative resistance to flow using Lee’s files and notes as one source of reference information. This review is completed and serves as a precursor to her analysis of Lee’s laboratory and field data. It also serves as a valuable reference resource for others contributing to this project.
Major scientific outcomes for this project during FY 2000 included:
1. The theoretical limits of applicability of Lee’s pipe manometer method for computing water-surface slopes have been determined and defined. This allows other researchers to identify situations in which the pipe manometer technique can be used to accurately measure the local water-surface slope.
2. The pipe manometer calibration data show a distinct, nearly-linear variation between the pipe centerline velocity and the square root of the water surface slope. For the pipe manometer geometry used on this project in both the field and laboratory, this implies that the developed calibration is applicable throughout the range of velocities typically observed in the Everglades (Calibration data collected in the laboratory span the range 0.3 cm/s - 7.5 cm/s).
Table 2 contains selected results of flume vegetation sampling for six months. Parameters are Average total biomass, Class (medium sawgrass), Total number of leaves at 40-60 cm, Total number of leaves at 20-40 cm, Total number of culms at 0-20 cm, Total number of culms at 20-40 cm, and Total dead biomass at 9 months, 13 months, 17 months, 21 months, 27 months, and 30 months.
Table 3 shows the summary of uncorrected Leaf Area Indices (LAI) for six plant ages (9 months, 13 months, 17 months, 21 months, 27 months, and 30 months) for 60-90 cm, 40-60 cm, 24-40 cm, 0-20 cm and total.
Table 4 shows data for the sawgrass biomass in the flume for September, 1995 (9 months)
Table 5 shows data for the sawgrass biomass in the flume for January, 1996 (13 months)
Table 6 shows data for the sawgrass biomass in the flume for May, 1996 (17 months)
Table 7 shows data for the sawgrass biomass in the flume for October, 1996 (21 months)
Table 8 shows data for the sawgrass biomass in the flume for March, 1997 (27 months)
Table 9 shows data for the sawgrass biomass in the flume for June, 1997 (30 months)
U.S. Department of the Interior, U.S. Geological Survey
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