Field-Scale Evaluation of Evapotranspiration from a Landfill Cover

Alternative final covers have been increasingly permitted due to the financial benefits and environmental sustainability offered by the use of native soils. However, often due to lack of validated transpiration models, practitioners ignore plants (or transpiration) when equivalency analysis is carried out for permitting. This study focused on evaluating the effect of plants on evapotranspiration (ET) and on the water balance of a 91-cm-thick earthen cover. Two 11 m x11 m (35 ft x 35 ft) test sections were built side by side (one planted by Vetiver grass, the other was bare representing control). One-year field data showed that there was no significant difference between overall water balance and ET of the two test sections. The Vetiver plants reached 50% of their specified matured height at end of the first year.