Sponge cities: sustainable places using nature-based solutions

Looking up view of panoramic modern city skyline with blue sky and green tree in Shinjuku, Tokyo, Japan

Researchers from the UK and China have created nature-based solutions (NBS) to reduce the impact of climate change in urban settings.

As you are reading this, climate change is happening all around us. Problems like flooding, drought, air pollution and wildfires are becoming more frequent and intense, destroying where we live, threatening our health and impacting people’s livelihoods.

Global floods and extreme rainfall have surged at a rate four times higher than in 1980, and in many cities, only 20 to 30% of rainwater seeps into the ground.

Cities worldwide are rapidly expanding, so what opportunities are available to us to better manage green spaces (parks, trees, woodland), blue spaces (rivers and lakes), and provide multiple benefits to people?

About the project

The team stood around a roadside runoff solution with umbrellas, Suzhou, China.

Nature based solutions for capturing road runoff, Suzhou in China. Credit: Michael Hutchins

Researchers from the UK Centre for Ecology & Hydrology (UKCEH) and the University of Nottingham Ningbo, China, have come up with the idea of sponge cities, that will use NBS to:

  • absorb and capture rainwater and utilise it to reduce floods
  • reduce water and air pollution, high temperatures and noise
  • improve recreation and health opportunities.

The project will look to design NBS by:

  • evaluating what leads to successful interventions
  • looking into the role of business and society
  • designing and financing innovative solutions developed in Chinese and European cities, which can then be followed worldwide.

Establishing urban NBS

Dr Michael Hutchins, Water Quality Modeller from UKCEH says:

By transferring knowledge of best practice between researchers and user communities internationally, the project seeks to help decision makers successfully plan and establish urban NBS.

This means identifying where NBS can best provide multiple benefits for the environment whilst also improving public access to these greenspaces.

We are particularly focusing on urban woodland and parkland. In working towards our aims, we strive to ensure the latest scientific evidence for NBS benefits is included in assessments.

Adapting to future challenges

Dr YU Shen, Institute of Urban Environment, Chinese Academy of Sciences, says:

This project aims to become the Chinese and European reference point for nature-based solutions on clean urban waters and incentivise businesses and society to help cities adapt successfully to future challenges from climate and population growth.

The research will help foster a more informed decision-making process of urban environmental management for the public.

How it works

By comparing case studies from Oslo (Norway), Birmingham (UK) and Suzhou (China) the team will compare the results of the NBS approach in the three countries.

The full project team is a collaboration between lead organisations, UKCEH and Institute of Urban Environment, Chinese Academy of Sciences with:

  • University of Oslo, Norway
  • Norwegian Institute for Water Research, Norway
  • Institute of Urban Environment, Tsinghua University, China
  • Earthwatch, UK.

This research will enable the team to identify the best design for optimal benefit by determining suitable ways to help cities adapt successfully to future pressures from climate and population growth.

The analysis will then influence policies to incentivise business and society to directly influence economic development and welfare. In summary, it will foster a more informed decision making process for a broader range of users.

Impact of the project

The project, due to finish December 2022, aims to become the European and Chinese NBS reference point for:

  • practitioners
  • researchers
  • policymakers
  • industry citizen science participants
  • wider society.

It will also look to define how environmental impacts on a larger scale can inform the choice of solutions adopted in urban areas and recommend design criteria and management strategies to optimise co-benefits.

Outcomes

Since the project began, the team have delivered seminars about the project to various groups including a webinar hosted by the Partnership for European Environmental Research.

A workshop was held with representatives from Birmingham City Council and Severn Trent Water. This was related to the UK case study, to identify their priority needs, and further engagement is planned as the project nears completion.

The UK team have been lead authors on three publications, which include Environmental Research Letters, Hydrological Sciences Journal and MDPI Sustainability. Respectively these publications covered:

  • development of a new conceptual approach to assess multiple benefits of NBS incorporating considerations of scale of NBS when guiding end users to identify the best locations
  • systematic literature review establishing the evidence for benefits of trees in preventing urban flooding
  • circular benefits of citizen science activity, which shows that participation in NBS monitoring activities leads to greater community involvement in both new implementations and maintenance of existing NBS.

The team have also co-authored a collaborative paper on the Chinese sponge city approach, with lead authors from the University of Nottingham Ningbo, published in MDPI Water.

Further outcomes will be shared later this year when the project finishes.

Top image:  Credit: voyata, iStock, Getty Images Plus via Getty Images

This is the integrated website of the seven research councils, Research England and Innovate UK.
Let us know if you have feedback or would like to help us test new developments.