@article{purvis_winston_hunt_lipscomb_narayanaswamy_mcdaniel_lauffer_libes_2019, title={Evaluating the Hydrologic Benefits of a Bioswale in Brunswick County, North Carolina (NC), USA}, volume={11}, ISBN={2073-4441}, DOI={10.3390/w11061291}, abstractNote={Bioswales are a promising stormwater control measure (SCM) for roadway runoff management, but few studies have assessed performance on a field scale. A bioswale is a vegetated channel with underlying engineered media and a perforated underdrain to promote improved hydrologic and water quality treatment. A bioswale with a rip-rap lined forebay was constructed along state highway NC 211 in Bolivia, North Carolina, USA, and monitored for 12 months. Thirty-seven of the 39 monitored rain events exfiltrated into underlying soils, resulting in no appreciable overflow or underdrain volume. The bioswale completely exfiltrated a storm event of 86.1 mm. The one event to have underdrain-only flow was 4.8 mm. The largest and third-largest rainfall depth events (82.6 and 146 mm, respectively) had a large percentage (85%) of volume exfiltrated, but also had appreciable overflow and underdrain volumes exiting the bioswale, resulting in no peak flow mitigation. Overall, this bioswale design was able to capture and manage storms larger than the design storm (38 mm), showing the positive hydrologic performance that can be achieved by this bioswale. The high treatment capabilities were likely due to the high infiltration rate of the media and the underlying soil, longer forebay underlain with media, gravel detention layer with an underdrain, and shallow slope.}, number={6}, journal={WATER}, author={Purvis, Rebecca A. and Winston, Ryan J. and Hunt, William F. and Lipscomb, Brian and Narayanaswamy, Karthik and McDaniel, Andrew and Lauffer, Matthew S. and Libes, Susan}, year={2019}, month={Jun} }
 @article{fox_muñoz-carpena_purvis_2018, title={Controlled laboratory experiments and modeling of vegetative filter strips with shallow water tables}, volume={556}, ISSN={0022-1694}, url={http://dx.doi.org/10.1016/j.jhydrol.2017.10.069}, DOI={10.1016/j.jhydrol.2017.10.069}, abstractNote={Natural or planted vegetation at the edge of fields or adjacent to streams, also known as vegetative filter strips (VFS), are commonly used as an environmental mitigation practice for runoff pollution and agrochemical spray drift. The VFS position in lowlands near water bodies often implies the presence of a seasonal shallow water table (WT). In spite of its potential importance, there is limited experimental work that systematically studies the effect of shallow WTs on VFS efficacy. Previous research recently coupled a new physically based algorithm describing infiltration into soils bounded by a water table into the VFS numerical overland flow and transport model, VFSMOD, to simulate VFS dynamics under shallow WT conditions. In this study, we tested the performance of the model against laboratory mesoscale data under controlled conditions. A laboratory soil box (1.0 m wide, 2.0 m long, and 0.7 m deep) was used to simulate a VFS and quantify the influence of shallow WTs on runoff. Experiments included planted Bermuda grass on repacked silt loam and sandy loam soils. A series of experiments were performed including a free drainage case (no WT) and a static shallow water table (0.3–0.4 m below ground surface). For each soil type, this research first calibrated VFSMOD to the observed outflow hydrograph for the free drainage experiments to parameterize the soil hydraulic and vegetation parameters, and then evaluated the model based on outflow hydrographs for the shallow WT experiments. This research used several statistical metrics and a new approach based on hypothesis testing of the Nash-Sutcliffe model efficiency coefficient (NSE) to evaluate model performance. The new VFSMOD routines successfully simulated the outflow hydrographs under both free drainage and shallow WT conditions. Statistical metrics considered the model performance valid with greater than 99.5% probability across all scenarios. This research also simulated the shallow water table experiments with both free drainage and various water table depths to quantify the effect of assuming the former boundary condition. For these two soil types, shallow WTs within 1.0–1.2 m below the soil surface influenced infiltration. Existing models will suggest a more protective vegetative filter strip than what actually exists if shallow water table conditions are not considered.}, journal={Journal of Hydrology}, publisher={Elsevier BV}, author={Fox, Garey A. and Muñoz-Carpena, Rafael and Purvis, Rebecca A.}, year={2018}, month={Jan}, pages={1–9} }
 @article{purvis_winston_hunt_lipscomb_narayanaswamy_mcdaniel_lauffer_libes_2018, title={Evaluating the water quality benefits of a bioswale in Brunswick County, North Carolina (NC), USA}, volume={10}, number={2}, journal={Water}, author={Purvis, R. A. and Winston, R. J. and Hunt, W. F. and Lipscomb, B. and Narayanaswamy, K. and McDaniel, A. and Lauffer, M. S. and Libes, S.}, year={2018} }