Determination of removal efficiency using vegetative filter strips based on various efficiency evaluation methods

In this study, through the monitoring of 17 rainfall events over the course of a 3-year period, and in conjunction with the use of vegetative filter strips (VFS), five cases were calculated using different methods and they were evaluated in terms of the non-point source contamination removal efficiency. The efficacy of the methods used for evaluating the removal efficiencies can change considerably depending on several factors such as the removal device type, drainage basin, and rainfall event. With VFS, the removal efficiencies were found to change in accordance with the vegetation coverage ratio, except in June and July, which for watersheds in Korea are the months when rainfall amounts are concentrated. As such, it is assumed that because the VFS removal efficiencies are significantly affected by the vegetation coverage ratio, a method that explicitly considers the vegetation coverage ratio would be most appropriate when calculating the efficiency of a removal facility such as VFS.