Hydrological Cycle Performance at a Permeable Pavement Site and a Raingarden Site in a Subtropical Region

Abstract

Low-impact development (LID) structures are widely used to mitigate urbanization impacts on hydrology. The performances of such structures are strongly affected by field conditions, such as the ratio of LID area to drainage area and rainfall properties, such as rainfall intensity. In this study, onsite continuous monitoring was performed at a permeable pavement site and a raingarden site in Taipei, Taiwan, to determine their water retention and groundwater recharge potential under subtropical weather. In addition, the verified Storm Water Management Model (SWMM) was used to illustrate the annual performance on the hydrological cycle. Based on one year of monitoring, data on 41 and 24 rainfall events were obtained at the permeable pavement and raingarden sites, respectively. The ratio of the permeable pavement area to the total drainage area was 36.0%, and this ratio was 15.9% for the raingarden. The results showed that the average runoff reduction rate was 14.7% at the permeable pavement site, and 98.3% of the rainfall was retained in the raingarden and an underground storage tank. The validated model showed that the permeable pavement site experienced 45.3% outflow, 31.6% evaporation, and 23.1% infiltration annually. For the raingarden with an underground storage tank, 91.4% of the annual rainfall infiltrated and was stored, with only 4.1% outflow. According to the observed rainfall event performance and the simulated annual performance, the permeable pavement and raingarden performed well in subtropical regions. Pavement that was approximately 1/3 permeable in a drainage area increased infiltration by approximately 20%, and a raingarden with a sufficient underground storage tank preserved over 90% of the rainfall.

Promoting Porosity: Adaptation of Urban Roadways for Flooding and Climate Change

“…The approach demonstrates how to target the use of permeable pavements at specific locations to reduce runoff, replenish groundwater, and reduce flood risk. These efforts should be integrated with stormwater management and low-impact development policies to generate cumulative positive benefits (39). The research supports a layered approach to resilience by starting first with environmental conditions including rainfall, topography, and land use, and then integrating traffic volumes, vehicle mix, and socioeconomic conditions.…”

“…While the initial costs of installation of permeable pavement may be higher than conventional paving, they may have lower maintenance costs over time (23,39,40). Ecological benefits of green infrastructure, harvesting and recycling rainwater, using readily available local rather than imported materials, and expanded training and development of standards and processes support workforce development goals that expand the return on investment in porous pavements (3,5,8,15,35,(41)(42)(43).…”

Investigation of the Permeability of Fibre-Modified Water Permeable Asphalt with Methods of Asphalt Petrology

“…The growth of urban areas with sealed surfaces at the expense of permeable natural surfaces has led to increased flooding, loss of urban infrastructure, and non-point pollution [1,2]. Furthermore, the sizable share of impermeable surfaces alters the natural water cycle in urban areas [3]. The pores in PA are higher in volume and more interconnected compared to conventional asphalt [4].…”