【摘要】 江苏潮滩面积大,岸滩冲淤动态变化复杂.人工引种互花米草对江苏海岸潮滩沉积地貌演化有较大影响,主要体现在影响潮滩沉积速率、物质分布及潮水沟地貌系统的发育等方面.根据定点站位不同年代的高程数据,分析Pethick-Allen模型在江苏潮滩盐沼的适用性;在现场采集柱状样并在室内进行137Cs分析,根据分析结果及前人研究结果,利用P-A模型分析计算江苏潮滩不同时期的沉积速率,结果表明互花米草的引种加快了潮滩沉积速率,它使潮滩沉积地貌演化脱离了原来的渐进函数关系.在选择的典型断面上采集表层底质样,在激光粒度仪上进行粒度分析,结果表明,互花米草易使细颗粒沉积物沉积,大米草滩和盐蒿滩表层沉积物主要来自潮水沟输送.根据野外调查并结合遥感分析,互花米草滩内潮水沟宽深比小,密度大,水道稳定,有别于光滩或大米草滩的潮水沟形态.更多还原

【Abstract】 The area of tidal flat in Jiangsu Province is the biggest in China,and the dynamic change of tidal flat erosion and accumulation is complicated.Spartina alterniflora is introduced artificially to the Jiangsu coast,which has significantly influenced the regional tidal flat evolution in terms of the deposition rate,sediment distribution patterns and tidal creek geometry.According to surface elevations of stations and calculated sedimentation rates in different stages,the applicability of Pethick-Allen model is analysed in Jiangsu tidal salt marshes.¹³⁷Cs analysis is carried out for sediment samples from the salt marshes of Wangang to determine the sedimentation rate.According to the ¹³⁷Cs analysis and the data form relative literature,using P-A model for calculating the sedimentation rates in different stages of Jiangsu tidal flat,the results show that the original patterns of tidalflat accretion has been modified since the introduction of Spartina alterniflora,this "intruding organism" has caused rapid accretion.Surficial sediment samples were collected on typical section,and analyzed for grain size by a laser particle analyzer（Mastersizer 2000,produced by Malvern Instruments in the UK）,the result shows that fine-grained sediment has been trapped by the plant,and the sediments deposited on Suaeda salsa and Spartina angelica flats enter the upside marsh mostly through drainage creeks rather than from gently sloping tidal flats.Analysis results of remote sensing and in situ observations indicate that the creeks developed on the Spartina alterniflora flat have a relatively small ratio of width to depth,a relatively high density,and are more stable than other tidal flat creek systems in the region.更多还原