Urban blue-green infrastructure (BGI) is a network of nature-based features
situated in built-up areas that form part of the urban landscape. These features
are either based on vegetation (green), water (blue), or both. Green roofs and
walls, grassed areas, rain gardens, swales (shallow channels, or drains), trees,
parks, rivers and ponds are all examples of this type of architecture. Blue-green
infrastructure is important as a climate change mitigation and adaptation measure,
and has a host of wider benefits to people and wildlife.

This briefing note summarises the benefits that blue-green
infrastructure brings to people, recent trends in the use of blue
or green features in urban settings, and the perceived barriers
to greater uptake in the UK and how these might be overcome.
This paper also explores how thinking about the way these
features fit within a wider system of natural and human factors,
so-called systems thinking, can help improve the evaluation of
blue-green assets from a range of different perspectives.