A New Strategy for Sponge City Construction of Urban Roads: Combining the Traditional Functions with Landscape and Drainage

Chengyao Wei,Jin Wang,Peirong Li,Yongbo Jiang,Tianyin Huang,Bingdang Wu,Hanhan Liu

doi:10.3390/w13233469

Abstract

Urban roads play a key role in sponge city construction, especially because of their drainage functions. However, efficient methods to enhance their drainage performance are still lacking. Here, we propose a new strategy to combine roads, green spaces, and the drainage system. Generally, by considering the organization of the runoff and the construction of the drainage system (including sponge city facilities) as the core of the strategy, the drainage and traffic functions were combined. This new strategy was implemented in a pilot study of road reconstruction conducted in Zhangjiagang, Suzhou, China. Steel slag was used in the structural layers to enhance the water permeability of the pavement and the removal of runoff pollutants. The combined effects of this system and of the ribbon biological retention zone, allowed achieving an average removal rate of suspended solids, a chemical oxygen demand, a removal of total nitrogen and total phosphorus of 71.60%, 78.35%, 63.93%, and 49.47%; in contrast, a traditional road could not perform as well. Furthermore, the volume control rate of the annual runoff met the construction requirements (70%). The results of the present study indicate that, combining the traditional basic functions of roads with those of landscape and drainage might be a promising strategy for sponge city construction of urban road.

Highlights

With the rapid process of urbanization and the increase of impervious surfaces in urban areas, great changes have taken place in the hydrological environment [1]
Urban non-point source pollution has gradually become a major problem for the improvement of the water environment, as it can be transported into flood flows from drainage systems [2,3]
The control of the runoff and the removal of the pollutants can be realized by optimizing urban roads and green spaces and by building suitable

Summary

Introduction

With the rapid process of urbanization and the increase of impervious surfaces in urban areas, great changes have taken place in the hydrological environment [1]. In order to control water pollution and improve the quality of the water environment and the utilization of rainwater, many countries have developed different concepts and technical measures according to their own conditions, such as measures based on low-impact development, best management practices, sustainable urban drainage systems, water-sensitive urban designs [4,5,6]. Considering this background, the sponge city (SC), a concept involving a series of innovative ideas, parameters, and methods, was proposed [7]. The concrete pavement was cracked, and the sidewalk could not properly allow walking.

Methods

Results

Discussion

Conclusion