Record Details
Bioretention Establishment Hydrologic Characterization with Drift Correction and Calibration of Fine Water Level Measurements
ScholarsArchive at Oregon State University
| Field | Value |
|---|---|
| Title | Bioretention Establishment Hydrologic Characterization with Drift Correction and Calibration of Fine Water Level Measurements |
| Names |
Livingston, Grant
(creator) Babbar-Sebens, Meghna (advisor) |
| Date Issued | 2015-06-08 (iso8601) |
| Note | Graduation date: 2016 |
| Abstract | Bioretention is a common form of green stormwater infrastructure that is used to attenuate peak flows from urban stormwater. Previous research shows that the bioretention peak response is not consistent across time or space and that the variables that affect peak hydrology are numerous. One variable that has not been well studied is bioretention establishment, or the indefinite period of time following installation during which the soils and plants mature until stabilization of hydrologic performance is achieved. Previous research has investigated changes in infiltration rate, but the peak flow response to this change in infiltration has not been quantified. The primary objective of this research was to characterize bioretention establishment peak hydrology. The runoff from a 9,300 m² drainage area was captured by a grey-green stormwater treatment train using an underground storage tank, a pump, and three parallel bioretention cells with underdrains. One of the cells was monitored for peak flows analysis from October 2014 to May 2015. The water level measurements were observed to drift by up to 29mm, introducing uncertainty into the flow rate measurements. A drift correction method was applied about every eight days to fix the drift. A water balance approach was then used to fine tune the outflow measurements for three storm events to minimize the residual of the water balance to less than 1% of the total inflow volume. Hydrologic function metrics of peak ratio and peak delay were then calculated to investigate the peak flow response to bioretention establishment. Mean peak ratios were 0.54, 0.68, and 0.61 and mean peak delays were 45 minutes, 63 minutes, and 59 minutes for the fall, winter and spring, respectively. No significant differences between the peak ratios were found, however, at least one peak delay had a different mean than the other peak delays (1 way ANOVA, p value < 0.01). This indicates that the establishment period does indeed affect the peak flow hydrology. Future studies should attempt to minimize error in flow rate measurement to further characterize the establishment period and understand how it affects peak flows to improve bioretention design. |
| Genre | Thesis/Dissertation |
| Access Condition | http://creativecommons.org/licenses/by/3.0/us/ |
| Topic | green stormwater infrastructure |
| Identifier | http://hdl.handle.net/1957/56388 |
