Definitions and context of blue-green infrastructure

Understandings of blue-green infrastructure (BGI) vary, depending on professional discipline. What we consider to be BGI differs in scale, type and function, leading to variation in what projects are delivered. This impacts directly on the terminology used – BGI, nature-based solutions (NBS) or low-impact development (LID) – and the subsequent framing of practice. To effectively understand, deliver and fund BGI, it is important to assess the antecedents and the core drivers and principles of the concept to locate its application in contemporary landscape and urban planning. Such debates also need to be located within an appreciation of existing policy or legal structures and professional practice of the natural, built and engineered professions to enable the core ideas of BGI to be mapped onto discipline-specific practices. Through an engagement with the temporal, spatial or scalar, geographical, functional and disciplinary variation inherent in BGI research and practice, we examine how it can address the prominent climatic, biodiversity, health and wellbeing and equity issues facing urban and rural areas. To achieve this, the following chapter examines the role of BGI as a transdisciplinary approach to development that purposefully aims to create consensus between practitioners by way of a collaborative exchange of knowledge and best practice. This focuses on how BGI can be used, what types of BGI work in different locations and how BGI can support more sustainable forms of water, ecological and socio-economic development.