Poster 221 – Click on poster below to view presentation from author.
University of Tennessee, Knoxville
Co-Authors: Jon Hathaway, Andrew Tirpak, Anahita Khojandi
As climate change produces shifts in precipitation patterns, communities will need to understand how the performance of green stormwater infrastructure (GSI) may be impacted. Bioretention cells are one of the most commonly implemented forms of GSI for their ability to reduce peak discharge and filter pollutants. Projections in future climate indicate that bioretention cells may be at risk of losing their existing function due to deviations in precipitation frequency and intensity. As such, an ensemble of 10 regional climate models and 17 locations across the contiguous United States were evaluated to provide the widest range of potential future outcomes. Bioretention cells were modeled using USEPA’s Storm Water Management Model (SWMM) to compare observed (1999-2013) and simulated future (2035-2049) performances. To reduce model bias, simulated future climate data was bias-corrected using kernel density distribution mapping (KDDM). Median annual rainfall and 99th percentile rainfall event depths were projected to increase across all 17 locations while median drying period was projected to decrease for 11 locations, indicating fewer events with higher magnitudes of rainfall for a majority of locations. Correspondingly, bioretention cell performance decreased across all 17 locations. Relative percent changes in infiltration loss decreased between 4.0-24.0% across all 17 locations while overflow increased between 0.4-19.6% for 15 locations. Results suggest that bioretention cells in the southern United States are at significant risk of losing their existing function while those in the Midwest and Northeast are at moderate risk. Bioretention cells in the western and northwestern United States performed the best under future climate scenarios but could still lose their existing function if unchanged. This study provides insight on future regional bioretention cell performance trends that can be used to add resiliency to stormwater infrastructure.
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All posts are publicly visible after review by site administrator. Students’ responses to posted questions is factored into scoring for the poster competition. Finalists announced May 25 and awards presented May 26, 2021.