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Accueil du site → Doctorat → États-Unis → 2017 → Evaluating Soil Type and Flow Path for the Optimal Balance of Infiltration and Evapotranspiration in Vegetated Stormwater Control Measures to Achieve Maximum Volume and Pollutant Removal

Villanova University (2017)

Evaluating Soil Type and Flow Path for the Optimal Balance of Infiltration and Evapotranspiration in Vegetated Stormwater Control Measures to Achieve Maximum Volume and Pollutant Removal

DelVecchio, Taylor Marie

Titre : Evaluating Soil Type and Flow Path for the Optimal Balance of Infiltration and Evapotranspiration in Vegetated Stormwater Control Measures to Achieve Maximum Volume and Pollutant Removal

Auteur : DelVecchio, Taylor Marie

Université de soutenance : Villanova University

Grade : Master of Science (MS) in Civil Engineering 2017

Résumé
Present rain garden design and research has focused on infiltration as the key volume reduction mechanism in vegetated stormwater control measures (SCMs), but the inclusion of evapotranspiration (ET) in the design of SCMs is a viable removal method. Design guidelines for soil types in rain gardens are often restrictive, but tailoring the soil media to site specific conditions, or using on-site soils, to promote either infiltration or ET can be beneficial to increase both volume and pollutant removal. A bench scale study was designed at Villanova University to assess the quantity and quality removal capabilities of five different USDA soil types. This study focused on investigating and quantifying two design parameters for vegetated SCMs, soil type and flow path, to maximize volume and pollutant reduction. It was hypothesized that the optimal balance between infiltration and ET for site-specific conditions will enable maximum volume and pollutant removal. The results of this study indicate that the type of soil media used in vegetated SCMs plays a large role in the volume reduction mechanisms. As the saturated hydraulic conductivity of a soil decreases and the plant available water increases, more volume is removed through ET than infiltration, and vise versa. ET is a seasonally dependent process, and as such, the distribution of volume removal between deep infiltration and ET is also seasonally dependent. Dependent upon season, antecedent dry time, and soil type, the cumulative volume removal effects of ET between storm events have the ability to surpass the cumulative volume removal effects of infiltration. A longer hydraulic retention time in the root zone was also shown to increase volume removal through ET. Nitrogen and phosphorus removal was not significantly affected by media type, so volume removal goals of the SCM should be the main factor in media selection.

Version intégrale (ProQuest)

Page publiée le 20 octobre 2017