Wave attenuation in coastal mangroves in the Red River Delta, Vietnam

Effects of different management regimes on mangrove ecosystem services in Java, Indonesia

“…For instance, VoLuong and Massel (2006) found that 50-70% of the wave energy was dissipated in the first 200 m of a mangrove forest, but Massel et al (1999) found that it varied between 20 and 55%, 150 m into the forest. The projected area of mangrove vegetation is closely related to species composition and age, as both factors determine the presence of different types and densities of roots, stems and branches (Massel et al 1999, Quartel et al 2007). …”

“…Characteristics that influence the ability of mangroves to reduce storm surge levels can be assumed to be quite similar to those mentioned above (wave attenuation), albeit with less certainty. Mangrove width, vegetation characteristics (roots, stems, branches) and topography have been mentioned as the major factors (Mazda et al 1997a, Quartel et al 2007, Zhang et al 2012). The main difference with wave attenuation is that storm surges cannot be assigned linear relationship to any of these factors.…”

“…Moreover, the species that generally occur in low intensity use mangroves have been positively correlated to wave attenuation and, to a lesser extent, storm surge protection (Mazda et al 1997b, Mazda et al 2006, Quartel et al 2007). …”

“…In fact, many mangrove plantations in Indonesia have been created specifically for their coastal protection potential (Bosire et al 2008). Although the presence of roots and reasonably high trees is a positive factor for coastal protection, the lack of structural and species diversity, and adult mangroves will diminish the level of coastal protection, especially in the case of storm surge protection (Mazda et al 2006, Quartel et al 2007. Although soil formation can be expected around plantations and silvo-fishery systems, it is difficult to assess whether soil surface elevation is able to keep up with sea level rise, also because plantations and silvo-fisheries are often relatively young.…”

“…Because of the species diversity, high age, density and length of roots, stems and branches, and related factors we assumed that the projected area and structural diversity of natural mangroves is sufficiently large, and the mangrove belt is sufficiently wide to attenuate smaller waves (Quartel et al 2007, Tanaka 2008, Hashim et al 2013. We assume that the width of natural mangrove barriers generally exceeds the width of maximum 500 m required for attenuation of waves height by 50 -99% (McIvor et al 2012a), because the high species diversity and age that is required to classify as protection mangroves is highly unlikely to occur in just narrow stretches of mangrove.…”