Towards a better understanding of Green Infrastructure: A critical review

Based on a comprehensive analysis of key definitions of Green Infrastructure (GI) and their conceptual evolution, we present a review of current GI mapping approaches at multiple spatial scales and their associated functional analyses. GI is an approach that is used to combine ecosystem services and human well-being to realize an efficient and sustainable use of spaces, hereafter named GI concept. The interdisciplinary database that forms the basis of our literature review includes peer-reviewed journal papers as well as books and documents published by international organizations, governmental agencies, and research institutions. By analyzing these publications not only English but also Chinese articles we present an exhaustive review that gauges the state and evolution of GI in chronological terms, and we discuss how GI should be further improved. We systematically examine what GI actually measures and question whether its current manifestations are consistent with its conceptual development. Furthermore, we seek to find out whether there are specific trends in the conceptual evolution of definitions of GI, and whether there are gaps between this evolution and the implementation of GI in the context of advancing sustainable development. We then draw attention to differentiation while analyzing GI functions and classifications. On this foundation, we discuss six primary principles and propose a number of ways of enhancing and applying GI in the future. Our review shows that, at this point in time, special emphasis on the core idea of multifunctionality is significant for depicting the 'state of the art' of the evolving GI concept. Finally, the study identifies multifunctionality as the solution best suited to enhance the GI concept and to open up potential avenues for further research.