Water Resilience by Centipedegrass Green Roof: A Case Study

Abstract

Centipedegrass (Eremochloa ophiuroides) is a low-maintenance turfgrass. The first extensive green roof of centipedegrass was established in TongZhou Civil Squares in 2014. However, storm-water-runoff reduction, water-retention capacity, and plant-water requirements by a centipedegrass green roof has not yet been defined. The soil moisture dynamics, rainwater-retention capacity, runoff reduction, and plant evapotranspiration were investigated by simulated centipedegrass green roof plots, which were constructed in the same manner as the green roofs in TongZhou Civil Squares in 2018. The results showed that the centipedegrass green roof retained 705.54 mm of rainwater, which consisted 47.4% of runoff reduction. The saturated soil moisture was 33.4 ± 0.6%; the excess rainfall over the saturated soil moisture resulted in runoff. The capacity of rainwater retention was negatively related to the soil moisture before rain events and was driven by plant evapotranspiration. Drought symptoms only occurred three times over the course of a year when the soil moisture dropped down to 10.97%. Our results indicate that the rainwater retained in the soil almost met the needs of plant consumption; a further increase of rainwater retention capacity might achieve an irrigation-free design in a centipedegrass green roof.

Urban stormwater characterization, control, and treatment

“…In addition, if the roof is used as a place of leisure or recreation, sedums are not appropriate. Hu, Liu, Liu, Cao, Chen, and Wang (2019) explored the use of centipedegrass as a green roof alternative in China. The green roof demonstrated reasonable hydraulic performance at 47.4% runoff reduction with minimal irrigation demonstrating applicability to the climate.…”

Green Roofs and Greenpass

“…The calculated ROS for the extensive greened designs is close to this requirement and only varies slightly, due to further consideration of non-greened project (roof) area too. The relevance of green roofs for sustainable urban water management has also been addressed in many papers in recent years [21][22][23][24].…”

“…They have a typical height of construction of 8 to 15 cm and are habitat for succulents, grasses and herbs (in this paper, the effects of such a green roof are analyzed). Frequently, green roofs are described as an element in the realm of sponge city and urban water management [18,[21][22][23][24]. The run-off coefficient of green roofs is described in different standards and regulations [19,20] with regard to the construction type of the green roof.…”