摘要
沉积物粒度是描述沉积环境的重要指标之一,利用沉积物粒度参数可以反演沉积物堆积过程、沉积水动力特征.通过对湛江红树林国家级自然保护内海湾、河口、潮坪区的红树林表层沉积物粒度分析的研究,结果表明:河口与海湾区的红树林沉积物以泥质为主;有堤坝保护的河口区红树林沉积物颗粒细,为悬移质体含量高且连续稳定的低能环境;红树林发育差的潮坪区红树林沉积物为砂含量较大且水动力较强的高能环境.并通过推算海湾区沉积物的沉积年代,结合样品粒度分析的结果得出了该地区风暴潮发生的大致时间.
Mangrove forest sediment in different landforms reflects different hydrodynamic conditions because of the different sedimentary environments and different sediment particle size characteristics.Mangroves in different stages of development have different ability to resist the effects of waves;therefore,there are mangrove sedimentary records of storm surge.There has been little research on the particle size characteristics of mangrove sediment in coastal wetlands.In this work,surface sediment samples were collected in the Zhanjiang Mangrove National Nature Reserve in August,2009,and then analyzed using a Mastersizer 2000（analysis range of 0.02 to 2 000 μm）.The Zhanjiang Mangrove National Nature Reserve has a wide mangrove distribution;in this study,different geomorphic units of mangrove sediment particle size characteristics are analyzed.The mangrove sediment in the estuary is mainly composed of well-sorted silt and clay.The mangrove sediment in the bay is mainly composed of silt,but a sediment section at the Gaoqiao sampling site has high sand content.There are two possible reasons for this： one is that the region experienced a strong storm surge disaster in that period of sedimentation,which resulted in an instant rise in the water level and brought much coarse sand to be accumulated;and the other is that the region at that time was unvegetated beach in an intertidal zone without mangrove protection or with only poorly developed mangrove protection,and the sediment is normal tidal flat sand.Different particle grades and changes in clay,silt and sand contents at the Tongming sampling site can reflect the history of local mangrove development.Dating sediment using the average deposition rate can indicate the approximate time that the storm surge occurred and provide an important theoretical foundation and method for systematic research on sediment in the mangrove wetlands.Analysis shows that from 1963 to 2002,the timing of the storm surge is consistent with the timing of the peak sand content in the study region,suggesting that the storm surge results in the mangrove sediment particle size becoming coarser.Gaoqiao might have experienced four large storm surge disasters in the period of 1929 to 1962 according to our research results.
出处
《台湾海峡》
CAS
CSCD
北大核心
2011年第2期269-274,共6页
Journal of Oceanography In Taiwan Strait
基金
中国地质大学(北京)学生学术基金资助项目(51913028)
关键词
海洋地质学
红树林
沉积物
粒度特征
风暴潮
湛江红树林保护区
marine geology
mangrove
sediment
particle size characteristics
storm surge
Zhanjiang Mangrore Nature Reserve
