Nature-based solutions and similar concepts on water management

Nature-based solutions (NbS's) refer to the sustainable management and use of nature for tackling socio-environmental challenges such as, focusing on water issues, water security, flood protection, and water pollutions. This newly emerging concept is conceptually compared, in the aspect of water management, to existing similar solutions with different naming, all of which are based on ecosystem functions. NbS seems significant and meaningful both educationally and understandably, since that it can comprehensively cover and include the existing methodologies and solutions using the services of the natural ecosystem to socio-environmental challenges. However, it seems not entirely different from the broad-meaning of green infra, including Eco-DRR, in the aspect of approaching methodologies in water management. The conceptual and spatial hierarchy of each practice can be expressed in the narrowing order of NbS - (Ecological engineering) - BGI (Blue-green infra) - (CRT, Close-to-river techniques) - GI (Green infra) - LID (Low-impact development).