Urban heat island mitigation and hydrology performance of innovative permeable pavement: A pilot-scale study

The permeable pavement is effective green infrastructure that can improve stormwater hydrology and mitigate urban inundation. However, its performance can be sharply weakened when it is used in an area having a high water table and low-permeability soil. This paper proposes an innovative permeable pavement (IPP) wherein capillary columns and an internal water storage zone formed by a high-density polyethylene liner are set up. To investigate the performance of the pavement in terms of its mitigation of the urban heat island effect and hydrological performance in an area with a high water table, four pilot pavements, including an impervious concrete pavement (CP), two permeable interlocking concrete pavements (PICP1 and PICP2), and the IPP, were constructed in a parking lot at our university campus and monitored throughout the year of 2018. Results reveal that the IPP better mitigates the urban heat island effect and had better hydrology performance than the other pavements. PICP1, PICP2, and IPP reduced the overall stormwater volume by 40.2%, 41.9%, and 90.6%, respectively, compared with CP. In 2018, there were only five outflow events for IPP, compared with 32 and 30 for PICP1 and PICP2 respectively. Moreover, the IPP had an obvious effect in mitigating the urban heat island effect throughout the monitoring process. Results revealed that during the hot-summer monitoring period, the maximum surface temperature of the IPP was 15.3, 15.8, and 14.4 degrees C cooler than those of CP, PICP1, and PICP2, respectively. The cooling effect of the IPP persisted if stormwater remained in the internal water storage zone. Statistical analysis revealed that the IPP significantly mitigated the urban heat island effect and improved the hydrology, compared with CP and PICP1 and PICP2 (p <0.01). (C) 2019 Elsevier Ltd. All rights reserved.