The effect of green roof configurations on runoff retention performance

Abstract

This study focused on the runoff retention performance within extensive green roof system with respect to different native plant species and configurations in Malaysia. A total of four green roofs were constructed with two configurations (with drainage and without drainage layers) and each test bed was planted with Portulaca grandiflora cultivars (sedum) and Axonopus compressus (cow grass), respectively. The runoff volume was measured volumetrically and water retention percentage was calculated for four monitored events at each green roof configurations. Results showed that sedum was the most effective native plant species in retaining runoff water. The green roof configuration with sedum planted in substrate and layers performed the best runoff retention efficiency in Malaysia. © Medwell Journals, 2018.