茅家港突堤工程建造前后滩面沉积物粒度变化及其原因分析

Change of Sands Grain-size and Analysis of Its Reason After Building of Maojiagang Jetty Project

为研究茅家港附近岸滩面沉积物粒度的变化,在对茅家港近岸滩面沉积物粒度研究的基础上,于1993年9月、1994年1月进行了两次野外采样调查,在室内进行了粒度测量。通过测得的一手资料,绘出不同时间的粒度空间分布图和不同位置的剖面图,对茅家港滩面沉积物粒度的空间分布、季节变化及其反映的水动力变化和原因进行了分析研究,论述了茅家港工程建造前后滩面沉积物粒度变化的规律和原因。研究发现:工程建成后,因突堤内水动力减弱,突堤内滩面沉积物的粒度变细,且比突堤外的细,航道不再淤积,使航道的位置和深度稳定,有效地保护了航道;随着离岸距离增加,因水动力逐渐增强,滩面沉积物的粒径逐渐变粗;因冬季的水动力比夏季的水动力强,冬季滩面沉积物粒度比夏季粗。

In order to research the change of Maojiagang sands grain-size, on the basis of the measurement and research of Maojiagang sands grain-size, we sampled and surveyed in September of 1993 and January of 1994, and measured the grain-size in the house. This paper draws grain- sizes distributing maps and different section charts with the data that we observed on Maojiagang sands, analyzes the spatial distribution of Maojiagang sands grain-sizes, the seasonal change and its change of water dynamics, and discusses the rule and reason for the change of Maojiajang sands grain-size. We point out： after the Maojiagang jetty was built, because the water dynamics inside dams has neckend, the sands grain-size inside dams has become smaller and that is smaller than it outside dams, the sea-route is not filled up. The position and depth of the sea-route are unchanged, as a result it effectively protects the sea-route; with the distance to the coast increasing, the grain-size becomes larger for water dynamics is stronger. Water dynamics in winter is stronger than that in summer, as a result of which the grain-size in winter is bigger than it in summer.