University of Florida
Development of Bankfull Discharge and Channel Geometry Regressions for Peninsular Florida Streams.
Degree: MS, Environmental Engineering Sciences, 2008, University of Florida
Regional curves, which relate bankfull discharge and channel geometry (cross-sectional area, width, and mean depth) to drainage area in regions of similar climate, geology, and vegetation, have greatly aided in creating target natural channel designs for stream restoration efforts. Regional curves were developed for peninsular Florida based on cross-sectional and longitudinal survey data collected at 17 gaged and 28 ungaged as near-to-natural streams, ranging in drainage area from 0.2 to 311 square miles and valley slope from 0.02 to 2.27%. Based on an analysis of prevalence among sites, slopes, and hydrologic data, the elevation of the flat floodplain was determined to be the most reliable bankfull indicator at sites with a wetland floodplain, while the elevation of the inflection on the bank was the most reliable indicator at sites with an upland floodplain. Analysis of bankfull indicator slopes further revealed that a water slope threshold of approximately 0.5% exists, above which bankfull indicators appear to more reliable, suggesting that slope-area techniques for calculating the bankfull discharge may be unreliable in peninsular Florida streams with a water slope less than 0.5%. The dataset was further divided based on physiography (flatwoods versus highlands), geography (northern versus southern peninsula), and floodplain types (wetland versus upland and cypress-dominated versus non-cypress-dominated) to determine if significant differences exist in the bankfull regressions and/or various dimensionless ratios (sinuosity, width-to-depth, maximum depth-to-mean depth, valley slope, and maximum discharge-to-mean annual discharge) among various peninsular Florida stream subsets. Streams with wetland floodplains were found to have a significantly greater bankfull area and bankfull width than streams with an upland floodplain. Also, streams with cypress-dominated floodplains had a greater width-to-depth ratio than streams with non-cypress-dominated floodplains. Further, streams draining flatwoods physiographies were found to be flashier. These differences may be important considerations when designing natural channels in peninsular Florida. Annual peak flow data for the gaged sites were analyzed to estimate the bankfull discharge return interval using Log Pearson Type III distributions. The bankfull discharge ranged from less than one year to 1.44 years, which is more frequent than the average 1.5-year return interval often cited in the literature. Based on analysis of the flow duration at gaged sites, bankfull discharge for peninsular Florida streams is equaled or exceeded approximately 21% of the time on average, or about 77 days per year. On average, the bankfull discharge is roughly four times that of the mean annual discharge and is 35% of the 1.5-year discharge. Lastly, the regional curves developed for peninsular Florida were compared to regional curves previously developed for other regions of the southeastern United States Coastal Plain. Peninsular Florida bankfull channels were found to have a lower…
Advisors/Committee Members: Wise, William R. (committee chair), Crisman, Thomas L. (committee member).
Subjects/Keywords: Coastal plains; Creeks; Floodplains; Geography; Geomorphology; Highlands; Rivers; Streams; Tributaries; Wetlands; bankfull, channel, curves, discharge, geometry, hydraulic, regional, restoration, stream; Manatee River ( local )
to Zotero / EndNote / Reference
APA (6th Edition):
Blanton, K. (2008). Development of Bankfull Discharge and Channel Geometry Regressions for Peninsular Florida Streams. (Masters Thesis). University of Florida. Retrieved from https://ufdc.ufl.edu/UFE0024089
Chicago Manual of Style (16th Edition):
Blanton, Kristen. “Development of Bankfull Discharge and Channel Geometry Regressions for Peninsular Florida Streams.” 2008. Masters Thesis, University of Florida. Accessed February 28, 2021.
MLA Handbook (7th Edition):
Blanton, Kristen. “Development of Bankfull Discharge and Channel Geometry Regressions for Peninsular Florida Streams.” 2008. Web. 28 Feb 2021.
Blanton K. Development of Bankfull Discharge and Channel Geometry Regressions for Peninsular Florida Streams. [Internet] [Masters thesis]. University of Florida; 2008. [cited 2021 Feb 28].
Available from: https://ufdc.ufl.edu/UFE0024089.
Council of Science Editors:
Blanton K. Development of Bankfull Discharge and Channel Geometry Regressions for Peninsular Florida Streams. [Masters Thesis]. University of Florida; 2008. Available from: https://ufdc.ufl.edu/UFE0024089