This report is a synthesis of detailed work commissioned from Deltares by WWF’s Resilient Asian Deltas Initiative that explores how Asian deltas can benefit from an integrated landscape approach to frame the implementation of Nature-based Solutions (NbS) at scale.

NbS are essential to increasing the resilience of riverine and coastal processes, and can help delta regions scale up their adaptation efforts. They are becoming an increasingly popular solution in water management practices, and have been advocated since the late 1990s, when the concept of ecosystem services began to gain traction.

Several international organisations, multilateral agencies, and financial institutions now see the potential of NbS, and are exploring ways to implement them on a larger scale. The challenge, however, is that most existing NbS are isolated and project-based, and not integrated into the larger ecosystem, diminishing the impact that they could potentially make.

This report attempts to address this by outlining a roadmap for a landscape approach to NbS in Asian deltas, which will help to build resilience by addressing all three subsystems of these ecosystems - biophysical, institutional and socio-economic. It explores how Asian deltas could benefit from an integrated system approach, and provides recommendations on how to proceed. It builds on already existing information, and ongoing initiatives in Asian deltas to demonstrate the added value of NbS, raise awareness for NbS at delta scale, and provide guidance for the selection of more cost-effective/higher impact NbS in Asian deltas.

This report also compares three Asian deltas to better illustrate how NbS can be upscaled - focusing on the Mekong, Ganges-Brahmaputra-Meghna (GBM) and Irrawaddy. It analyses the three subsystems in these deltas to provide an assessment of their current status, and lays out specific recommendations and conclusions to upscale NbS in these regions.

Each delta has its own unique challenges, but they also exhibit significant similarities in the way they
are affected by anthropogenic and climate induced changes. Upscaling NbS in Asian deltas will require large-scale systemic transformations in governance, financing and economic processes to ensure that biodiversity and people can adapt to - and be protected from - the worst impacts of climate change. Implementing NbS will also help ensure improved food and water security, health, and a more sustainable path for people and nature that depend on
these deltas.

The report makes a strong argument for implementing NbS on a much larger spatial scale, and integrating it into a landscape approach, which addresses both upstream-downstream linkages, and channel-floodplain processes, cumulative impacts but also how different NbS can de-risk one another. It helps to identify challenges that deltas are currently facing in upscaling NbS, and offers solutions to move beyond them. It underscores the importance of adopting a system approach and paying attention to the synergies between different ecosystems, to understand how the larger ecosystem functions as a whole and how this makes it more resilient.