2025-12-10 和歌山県
図 4 波高低下率のまとめ。礁嶺が低潮位時に干出している 3 地点（石垣島白保サンゴ礁と久米島大原サンゴ礁、奄美大島土盛サンゴ礁）では、将来の波高低下率は 80％以上であった。礁嶺の高さが低潮位時の海面とほぼ同じである沖縄県伊計島伊計サンゴ礁と、サンゴ礁が発達していない和歌山県串本町有田では、将来、サンゴの成長が継続していると波高低下率を増加させることが、検定結果（有意水準 5％）から明らかとなりました。 ※原論文の図を引用・改変したものを使用しています。
＜関連情報＞
- http://wave.pref.wakayama.lg.jp/news/kensei/shiryo.php?sid=43956
- http://wave.pref.wakayama.lg.jp/news/file/43956_0.pdf
- https://www.jstage.jst.go.jp/article/galaxea/27/1/27_G27-13/_article/-char/ja
2100年までに海面上昇と熱帯低気圧により琉球諸島と日本本土の波高が増加する中で、サンゴの成長により波高が減少する Wave height reduction by coral growth within the context of increased wave heights owing to sea-level rise and tropical cyclones in Ryukyu Islands and the main island of Japan by 2100
Chuki Hongo, Akira Iguchi, Masashi Kiguchi
Galaxea, Journal of Coral Reef Studies Published:2025/12/04
DOI:https://doi.org/10.3755/galaxea.G27-13
抄録
Coral reefs act as green infrastructure by forming coral- and reef-based natural breakwaters. Numerous studies on existing and future reefs have investigated the effectiveness of reef crests associated with upward coral growth in dissipating waves. However, estimates of wave height reduction by completely emergent reef crests at tectonically active sites and non-reef structures are poorly constrained. In this study, we present a quantitative analysis of the changes in wave height reduction owing to emergent reef crests and non-reef structures in Ryukyu Islands and the main island of Japan, while also considering the effects of sea-level rise and intensified tropical cyclones by 2100. Our findings indicate that the more emergent the reef crest, the greater is the effectiveness of wave height reduction. Moreover, our data showed that the rate of wave height reduction was diminished by reefs with fewer emergent crests and non-reef structures. However, at these sites, reefs expected to grow in response to sea-level rise until 2100 exhibit significantly greater wave height reduction than degraded reefs without reef growth. One reason for this is that in non-reef structures or reefs where the reef crest is not exposed, the accommodation space for coral growth in both the vertical and horizontal directions is created owing to sea-level rise.
