长江口潮间带淤泥质沉积物粒径空间分异机制  

Spatial difference mechanism of sludge sediment grain size in tidal wetlands of Yangtze delta

作　　者：李华[1] 杨世伦[1] T. Ysebaert 王元叶[1] 李鹏[1] 张文祥[1] 

机构地区：[1]华东师范大学河口海岸学国家重点实验室,上海200062 [2]荷兰生态学研究所,4400 AC Yerseke

出　　处：《中国环境科学》2008年第2期178-182,共5页China Environmental Science

基　　金：国家自然科学基金资助项目(40671017);国家“973”项目(2004CB720505);上海市科委重点基金资助项目(06dz12302);教育部创新团队发展计划项目(PCSIRT0427)

摘　　要：为了解淤泥质潮间带沉积物粒径空间分异规律及其控制因素，于2005年9月、2006年9月在长江口崇明东滩进行了沉积物取样分析及相关的水动力观测和盐沼植物粘附悬沙的实验.结果表明，潮间带沉积物呈自海向陆（表层样）和自下向上（柱状样）变细的趋势，一般光滩沉积物粒径〉50μm，盐沼上部沉积物粒径〈25μm；沿岸方向上，茂密盐沼的沉积物较之稀疏盐沼细；盐沼中的流速和波高较之相邻光滩减少50%以上；植物粘附悬沙干重达39-369g/m^2.对上述沉积物空间变化格局的形成机制分析认为，在光滩上主要是由于底床摩擦导致的水动力向岸衰减，在盐沼中则是植物和底床共同摩擦导致的水动力减弱以及植物茎叶对细颗粒悬沙的粘附.人类活动在改变盐沼植物特征的同时也会改变沉积物粒径的空间分异.In order to understand spatial difference rule of sludge sediment grain size in tidal wetlands and control factors, the test of sediments sampling analysis and hydrodynamics observing and salt marsh vegetation posting suspended sand were carded out in Chongming eastern beach of Yangtze delta in September of the years 2005 and 2006. The tidal wetland sediment appeared the tendency of changing small from sea to land （surface type） and from bottom to top （column type）. The mean size of the sediments was greater than 50μm on the tidal flat whereas it was less than 25μm in the upper marsh. The sediment of flourish salt marsh was thinness than that of sparse salt marsh. Wave-height and flow velocity in salt marsh was less over 50% than that of the adjacent tidal flat. The net weight of vegetation posting suspended sand reached 39-369g/m^2. The analysis of controlling mechanism of spatial changing pattern of sediment at mentioned above holder that the attenuation of hydrodynamics towards bank on high beach was mainly. In the salt marsh, however, the attenuation of hydrodynamics and posting of vegetable stem and leaf on small particle suspended sand were caused by joint friction of vegetable and bottom bed. At the same time of human activity changing salt marsh vegetations could also change the spatial difference of sediment grain size.

关 键 词：沉积物 粒径 潮间带 水动力 盐沼植物 长江口 

分 类 号：X145[环境科学与工程—环境科学]