Although mangroves reduce the daily risk of flood for millions of people, it is still difficult to estimate the protection they provide for variable wave conditions and forest characteristics. This aspect is crucial for the promotion of conservation and restoration of mangrove forests and for the estimation of how the coastal protection service they provide will evolve over time. This paper presents evidence and a new method for the estimation of the relationship between mangrove forest age and wave attenuation. The forest under analysis is characterised by the age of the Rhizophora mangrove trees, where consideration is given to the differences in the maturity of its individual trees and the density of the forest. Environmental conditions are defined by water levels and incoming wave height and period. A set of empirical and analytical relations expressing wave attenuation as a function of the submerged solid volume fraction (SVF) are presented. Changes is tree morphology and forest characteristics with forest age, as well as the contribution of the tree canopy, are taken into account. Results indicate that, after restoration, it may take only 5 years to obtain a forest's maximum coastal protection capacity. Additionally, such capacity appears to be maintained throughout the forest's lifetime with minor variations, provided the forest is not affected by any conditions altering its health, such as extreme wave events or anthropogenic action that may modify its habitat. Our findings present a new approach to quantifying the protection provided by mangroves without requiring any calibration. These findings can also assist in planning mangrove restoration and assessing associated benefits by providing the incorporation of nature-based solutions or ecosystem-based adaptation into coastal management.

尽管红树林降低了数百万人的日常洪水风险，但仍难以估计它们为可变波浪条件和森林特征提供的保护。这方面对于促进红树林的保护和恢复以及估计它们提供的海岸保护服务将如何随着时间的推移而发展至关重要。本文提出了估计红树林年龄与波浪衰减之间关系的证据和新方法。分析中的森林以红树的年龄为特征红树林，其中考虑了其个体树木的成熟度和森林密度的差异。环境条件由水位和来波高度和周期定义。一组经验和分析关系，将波衰减表示为浸没固体体积分数 ( SVF)的函数) 呈现。变化是考虑了树木形态和森林特征随林龄的变化，以及树冠的贡献。结果表明，恢复后，森林获得最大海岸保护能力可能只需要5年时间。此外，只要森林不受任何改变其健康的条件（例如可能改变其栖息地的极端波浪事件或人为活动）的影响，这种能力似乎会在整个森林的整个生命周期中保持不变，变化很小。我们的研究结果提出了一种无需任何校准即可量化红树林提供的保护的新方法。