How does the economic valuation of ecosystem services from natural floodplains contribute to the justification of nature-based flood solutions?

Economic valuation of ecosystem services is the process of quantifying, in monetary terms, the benefits that humans derive from ecosystems. In the context of natural floodplains, this involves assigning a financial value to the functions these ecosystems provide that support human well-being. A natural floodplain is a low-lying area adjacent to a river that is periodically inundated by water during high flows, allowing the river to expand naturally. These floodplains provide multiple ecosystem services, which are the direct and indirect contributions of ecosystems to human welfare. The primary ecosystem service from natural floodplains relevant to flood management is flood attenuation or regulation. This occurs as the floodplain slows down and temporarily stores excess river water during peak flows, thereby reducing downstream flood peaks and intensities, and mitigating flood damage. Beyond flood regulation, floodplains also offer critical co-benefits such as water purification by filtering pollutants and sediments, groundwater recharge, provision of habitat for biodiversity, ....