国際廃棄物資源ジャーナル

概要

Canopy Rainfall Intercepted by Nineteen Tree Species Grown on a Phytocapped Landfill

Kartik Venkatraman and Nanjappa Ashwath

“Phytocapping” is an alternative landfill capping technique that consists of two components, viz. soil cover and vegetation. The soil cover stores water during rainfall events and the vegetation; in this study, trees remove stored water via transpiration and reduce the amount of rain reaching the ground surface via canopy rainfall interception. These attributes contribute significantly to hydrological balance of the phytocap thereby preventing rainwater from entering the buried waste. Canopy rainfall interception was studied for the first time in 19 tree species grown in a landfill environment. Various parameters contributing to canopy interception were monitored over 2 years using 19 tree species that were established on two types of phytocaps (Thick cap 1400 mm soil and Thin cap 700 mm soil). Stemflow and throughfall were determined during 50 rainfall events over two years. Results showed that the established species were able to intercept up to 50% of the rainfall on a per storm basis, with an overall average of 30%. Stemflow also varied between species, but its overall contribution to site water balance was only 4.5% of the total rainfall received.