Green Infrastructure for Stormwater Runoff Control in China

Abstract

In the early 21st century, high-intensity human activities have led to the rapid development and expansion of urban areas in many countries, and these have had several adverse impacts upon the water environment. In particular, urban runoff quantity and quality control have emerged as key concerns for municipal officials. China, as one of the countries with rapid urbanization, faces many challenges in this process. Since the year 2000, China has been promoting the protection of its urban water environment using ecological construction. Use of green infrastructure (GI) to solve urban stormwater issues have become the priority of urban green and sustainable development. The Sponge City (SPC) approach was proposed to emphasize the comprehensive construction of multi-objective stormwater drainage and flood mitigation systems, and to consider water ecology, public safety, environmental protection, and preservation of water resources. The goal of GI is to achieve storm runoff quality enhancement and pollution control, which is similar to the sustainable development concept of SPC. According to its major functions, GI can be divided into infiltration and retention GI, regulation GI, transmission GI, pollution interception and treatment GI. GI should be planned and designed according to the long-term runoff volume capture ratio, which is determined by the annual rainfall depth and the level of catchment development at the project site. Different structural layer materials and spatial layout of GI have significant impact on their effects. Upon the completion of a project, long-term monitoring is recommended for evaluating its effectiveness. In order to ensure the continuous efficiency of GI, it is necessary to carry out regular maintenance. Different types of GI demand various maintenance methods and frequencies. Appropriate maintenance methods can effectively extend the service life of GI.