对海桑-无瓣海桑红树林生态系统进行为期1年(2007年11月—2008年11月) 的实地监测,分析不同气象条件对红树林防浪效应的影响,通过波高、流速等数据的变化对红树林的消波效能进行定量分析。结果表明:1)30m宽的海桑-无瓣海桑红树林带平均消波系数为 0. 12,最大消波系数可以达到 0. 47;风暴潮期间平均消波系数为 0.18,最大消波系数为 0.33,消波效能提升了 38% ; 2)根据消波系数公式计算 30 m 宽红树林带的消波系数为 0. 58,远大于实测消波系数; 3)一般情况下,海桑 - 无瓣海桑红树林对于波浪的消减效能随着来波波高的增大而增大,但是当海水将林木全部淹没时,林带基本失去消波能力,甚至发生林后波高大于林前波高的现象,这说明林分高度对红树林防浪护岸效益有着重要的意义; 4) 在潮位起伏的海岸环境中,不同树种、林龄搭配的多层次结构有利于提高红树林的综合消波防浪功能。
In this paper, effect of Sonneratia caseolaris-S, apetala mangrove ecosystems on wave absorption was studied by monitoring the wave height, flow rate and weather conditions for one year (November, 2007-November, 2008). We analyzed the impact of weather conditions to wave-prevention effect of the mangrove forest, and quantitatively analyzed the wave-prevention effect of mangrove forest through the wave height and flow rate variation. Results showed that: 1 ) the average wave absorption coefficient of 30 m wide mangrove forest was 0. 12, and the largest wave absorption coefficient achieved 0.47. During the storm the average wave absorption coefficient was 0. 18, the largest wave absorption coefficient was 0.33, and the wave absorption effect increased by 38%. 2) According to the calculated formula of wave absorption, the wave absorption coefficient of 30 m wide mangrove is 0.58, is much greater than the measured wave absorption coefficient. 3) Under normal condition, the wave absorption effect of Sonneratia-Sonneratia apetala mangrove forests increased as wave height increased. However, when all the trees were inundated, the forest almost lost its wave absorption effect, even wave forest rear was higher than that of the forest front, indicating that forest height had important significance to wave-prevention and revetment benefits of the mangrove forest. 4) On coastal environment of tidal level wavy, different tree species and age forests formed multi-level structure, which improved comprehensive wave absorption and wave- prevention function of mangrove forests.