UCCRTF report presents lessons learned from the implementation of Nature-based Solutions
A new report ‘Enabling the uptake of Nature-based Solutions in Asian and Pacific cities’ from the Urban Climate Change Resilience Trust Fund (UCCRTF) reflects on lessons learned from the implementation of Nature-based Solutions (NbS) in its work. The report highlights tools and techniques that support the design, delivery and implementation of NbS in cities across Asia. Case studies are presented to showcase the data available and the wide range of environmental, social, cultural benefits, as well as a framework for quantifying these benefits in economic terms.
The report’s findings were presented as part of ADB’s Nature and Climate Nexus Webinar Series: “Promoting Nature-based Solutions for Sustainable Infrastructures in Asia and the Pacific”. The webinar was held on 24th October 2022, and discussed the factors that make it challenging to quantify the socioeconomic, ecological, and financial benefits of NbS. Speakers presented different approaches that may be used to assign measurable benefits to these interventions.
Urban growth that progresses through ‘business as usual’ approaches to planning and infrastructure design and delivery has been shown to contribute to biodiversity degradation and to have adverse consequences for planetary health, including food shortages and a lack of clean air and drinking water. NbS provides city planners with a valuable suite of bio-engineering solutions that have the potential to address multiple, interrelated challenges. NbS describes a wide range of interventions that, when applied systemically, can help to protect and restore natural ecosystems, whilst simultaneously promoting human well-being and biodiversity benefits.
When implemented effectively, NbS can align with critical urban development agendas and has the potential to help address societal challenges, delivering benefits for both nature and people. It provides an alternative to traditional engineering solutions, or may be used in conjunction with them, to deliver outcomes that support biodiversity and promote the natural environment, often at a lower cost than traditional ‘grey’ solutions.
For example, NbS can help address climate change challenges and support the goals under the Paris Agreement by protecting, restoring, and regenerating ecosystems to reach carbon mitigation and adaptation targets. NbS also aligns with the Leaders Pledge for Nature through the enhancement of biodiversity, restoration of habitats and regeneration of natural environmental processes.
UCCRTF has found that implementing NbS is a good way to build resilience in infrastructure, communities, and the environment. Bridging together the many aspects of successfully building resilience to climate change, the ADB-UCCRTF Resilience Framework identifies four key areas that underscore the importance of systems-based holistic planning, multi-level governance strengthening, social networks, and financial management instruments.
NbS can deliver outcomes across a range of resilience dimensions, as referenced across the ADB-UCCRTF Resilience Framework’s four key areas: Ecological, Physical, Financial and Economic, and Social and Institutional resilience (Image 1).
Image 1: ADB’s Holistic Approach to Resilience
Ecological Resilience: support the conservation, protection and restoration of ecosystems and increase biodiversity through enhanced habitat diversity and the implementation of local protected areas and other effective area-based conservation measures.
Physical Resilience: reduce damage to infrastructure and the built environment through the integration of natural elements. These include small-scale interventions such as sustainable urban drainage systems (SUDS) and large-scale interventions such as the creation of wetlands, mangrove forests, and sand dunes.
Social and Institutional Resilience: mobilise community and cross-sectoral/administrative boundaries through community engagement and the application of structured approaches to informing infrastructure and land-use design with climate hazard data and social vulnerability mapping.
Financial Resilience: deliver greater cost efficiency through promoting more sustainable supply chains and circular economy principles, as well as supporting greater financial preparedness through cost savings available from avoided costs from future damages
Tools and Techniques
Along with supporting various NbS-related projects across Asia, the UCCRTF supports the adoption of nature-positive solutions by developing and applying tools and techniques that drive adaptation and resilience outcomes. Its uptake can be enhanced if cities and communities consider interventions that go beyond project or administrative boundaries to address climate change issues that extend beyond these boundaries, i.e., flood risk management, air quality, water resources management, watershed management, etc.
UCCRTF supported the development of the Spatial Data Analysis Explorer (SPADE), a web-based GIS visualization platform, that allows users to overlay various datasets (climate information, socio-economic data, land use, flooding patterns, etc.) on project sites to understand the interaction of the different components on each other. Using SPADE, the trust fund was able to demonstrate how basin-wide modelling and hazard mapping can help with the identification of integrated solutions, including NbS, to address water-related issues and flood impacts.
Another tool is the preparation of climate risk and vulnerability assessments (CRVAs) at various scales (national, regional, city level) to determine the specific climate risks affecting an area. When conducting CRVAs, it is important to downscale the data to the smallest geographical unit possible to generate more granular information. Carrying out CRVAs at the project concept stage can determine the combination of traditional and nature-positive solutions that directly respond to the area’s climate risks. For example, basin-wide modelling of water-related disaster risks under UCCRTF-financed TA 9129 enabled the identification of NbS for promoting smart integrated water management and informed the project design for the Integrated Urban Flood Management Project for the Chennai-Kosasthalaiyar Basin Project.
Community-led action presents a valuable technique in supporting NbS. NbS are determined by site-specific natural and cultural contexts, highlighting a need for communities to actively participate at all stages of implementation to ensure solutions are both practical and effective in a local context. UCCRTF is piloting community-led projects (CLPs) in eight secondary cities in three countries: Bangladesh, Pakistan, and the Philippines. As part of this work, UCCRTF has supported the formation of Community Stakeholder Groups (CSGs), a key mechanism for ensuring that resilience planning promotes the meaningful participation of women and vulnerable and marginalised groups. By combining community engagement with NbS project development and implementation, planners ensure that NbS projects reflect community needs, and provide the community an opportunity to participate in projects’ long-term management and sustainability. These social benefits are in addition to the significant cost savings of NbS over ‘grey’ solutions.
Increasing the application of NbS relies on building a strong business case, which in turn involves quantifying the associated benefits.
When compared with grey infrastructure, NbS is sometimes perceived as complex, costly, and uncertain. Shifting this perception requires strong evidence to ‘make the case’ for investment. Monitoring and measuring the impact of NbS can provide evidence for influence. However, several challenges are recognised in quantifying the benefits of NbS. For example, NbS provides wide-ranging social, cultural and environmental benefits that may be difficult to quantify.
To address this, a range of frameworks and approaches have been developed to assess the benefits and co-benefits of natural capital and ecosystem services. The report reviews a selection of these approaches to quantify the benefits of NbS projects.
A range of indicators and metrics that could be applied to measure the benefits of NbS were collated and presented across the four resilience dimensions (Image 2). The structure of the benefits framework provides the starting point for further refinement of the indicators and metrics to be appropriate for ADB projects. The framework highlights benefits such as increased soil quality, reduced risks to critical urban infrastructure resulting from climate hazards, avoided health costs linked to disasters and flooding, and increased knowledge of urban ecosystems.
Image 2: Indicators to measure the benefits of NbS
The economic components of the benefits framework were applied to two projects supported by the UCCRTF. In the Philippines, planners reviewed New Clark City’s master plan and provided recommendations for how NbS could support the city’s climate and flood resilience, for instance by restoring the ecosystem and enhancing green space around the Cut-Cut River to provide additional water storage. In Indonesia, a coalition of local leaders, governments and partner institutions piloted household-level NbS projects for water supply, wastewater treatment and/or drainage. Applying the benefits framework to both projects highlighted how the integration of NbS components supports economic benefits through cost savings, added economic value and/or lower socio-economic impacts.