Green Roof Hydrology: Results from a Small-Scale Lysimeter Setup (Bronx, NY)

摘要

A small scale lysimeter setup situated on the green roof of the Ethical Culture Fieldston School in the Bronx, NY has been the focus of ongoing monitoring initiated in June 2009. Data collected from the lysimeter setup and associated experimental equipment including a rain gage, soil moisture sensors and tipping bucket gage (for qualitative runoff monitoring) has provided the basis for the calculation of runoff and percent stormwater retention during storm events, as well as evapotranspiration (ET) during antecedent periods. Relationships between percent stormwater retention and governing factors such as total storm depth, antecedent period, storm duration etc. have been explored. Additionally, methods of estimating potential ET were compared to measurements of actual ET to examine the applicability of these approaches to green roofs. Results from the analysis of runoff and ET from the small scale lysimeter setup support the need for further research in estimating and evaluating water fluxes from green roofs as well as appropriate techniques for measuring and estimating these fluxes.