福建长乐海岸横向前丘表面粒度分异研究

在我国横向海岸沙丘分布的典型地区之一——福建长乐海岸，选择典型的横向前丘，按与横向前丘走向相垂直方向，分三个采样断面近等间距地采集了共81个沙丘表面沉积物的粒度样品，通过对采集样品平均粒径、分选系数、偏度和峰态等粒度参数的计算与分析，研究横向前丘表面的粒度分异特征。结果表明，福建长乐海岸横向前丘表面粒度的总体特征为细沙、分选较好、近对称和中等峰态，符合海岸沙丘粒度一般规律；长乐海岸横向前丘表面的粒度参数在沙丘表面不同部位基本一致，整个沙丘表面的粒度没有明显差别；粒度无明显差异的分布模式应是该区域风向交替变化的季风、强劲风力的台风、平缓的地势、沙丘高度不够、植被覆盖较好等作用的结果。

Distribution Model of Grain Size on Coastal Transverse Foredune at Changle in Fujian Province

The 81 samples were collected over three profiles on typical coastal transverse foredune,which is directly across the foredune,at Changle coastal region in Fujian Province that is one of the most typical coastal aeolian distribution regions in China.The parameters of grain size of 81 samples were analyzed and calculated by use of the number of mean size,standard deviation,skewness and kurtosis.The results show that the basic characteristics of grain size over coastal transverse foredune are accordant with the normal rule of coastal aeolian dune grain size,such as fine sands,high sorting degree,symmetrical skewness and middle degree kurtosis.It was also found that the parameters of grain size at different sites over typical coastal transverse foredune were almost the same,which had no distinct difference.The reasons of this distribution pattern of grain size on coastal transverse foredune at Changle City in Fujian Province mainly lie on the change of wind directions depending on monsoon,the influence of typhoon,smooth surface and low height of dune as well as good vegetation cover.