Comparative Analysis on Urban Flood Countermeasures Based on Life Cycle Thinking: A Comparison between Enhancing of Drainage Capacity Project and Sponge City

Xuezhou Fan,Toru Matsumoto

doi:10.3390/environments7070051

Abstract

The recent increase in rainstorm waterlogging disasters has acutely threatened sustainable urban development in China. Traditional strategy to solve this problem is drainage capacity enhancing projects, which aims at enlarging the discharge of water. Recently, there is a new countermeasure emerged in Chinese cities: ‘Sponge City’, which aims at enlarging the absorption of water by increasing the curves of urban land. This article endeavours to make a comparison between these two countermeasures by building a framework to design and analyze the private or social costs of two projects which have the same rainwater control capacity. Finally, we have come to the conclusion that only considering initial cost, Sponge City unit cost is much more than drainage capacity enhancing project unit cost; considering external cost, Sponge City is not only competitive from an economical perspective, from an environmental perspective Sponge City is also competitive.

Highlights

From the 1970s until now, China has experienced a rapid urbanization increasing phase
Drainage capacity enhancing infrastructure design involves a large-size combined sewerage pipes pipes replacement project, which is constructed in open‐cut way; Sponge City construction includes pipes replacement project, which is constructed in open‐cut way; Sponge
Considering external costs, the unit cost of the drain replacement project is smaller than the unit cost of Without considering external costs, the unit cost of the drain replacement project is smaller than the the Sponge City project; with considering external cost, the former is bigger than the latter, unit cost of the Sponge City project; with considering external cost, the former is bigger which has shown that Sponge City is sustainable to employ in urban environments

Summary

Introduction

From the 1970s until now, China has experienced a rapid urbanization increasing phase In such a rapid process of urbanization, land use change from natural landscape (e.g., green spaces, vegetation areas, forestry, and soil surfaces) to urban land-use (e.g., commercial, residential, and industrial) has been unprecedented. In this way a reduction in permeable surfaces and rainfall infiltration has resulted in a lower retention capacity for storm water in urban areas and less recharge of underlying groundwater. A number of cities have suffered recurrent flooding as their outdated drainage systems fail to cope with the rainstorms. The average rainfall in the city was 170 mm, and that in the city center was

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