黄河三角洲埕岛地区近年海底冲淤规律及水深预测

THE FEATURES OF SCOURING AND SILTING AND THE PREDI-CTION OF WATER DEPTH IN THE CHENGDAO AREA OF THE YELLOW RIVER DELTA IN RECENT YEARS

通过对1976～1995年黄河三角洲地区埕岛海域的水深资料以及近年来实测的水深数据的分析,确定了黄河三角洲埕岛地区在1976年黄河改道清水沟后,从三角洲推进淤积期进入了海岸冲刷改造期。按冲刷速率、剖面坡度及其与季节变化的关系可分为快速冲刷阶段(1976～1980)、缓慢冲刷阶段(1981～1992)、以冲刷为主的冲淤调整阶段(1992年至今),海岸边带的后期冲刷改造受季节性影响也比较明显。在深度上基本以15m等深线为界,深水区淤积、浅水区冲刷。通过250m×250m网格化节点的实测水深变化的时间序列,采用二维平面的趋势面拟合方法,可以较好地对本海区的水深进行拟合并做出时间序列值的预测。

Through analysis ,on the data of water depth from 1976 to 1995 and in recent years,it is determined that Chengdao area of the Yellow river delta has been changed from the period of delta silting to the period of seacoast scouring and rebuilding since the Yellow river channel transferred to the Qingshui gou in 1976. It can be divided into the period of rapidly scouring(1976 to 1980), slowly scouring(1981 to 1992)and adjustment to scouring and silting(1992 to present ).Late coastal scouring and rebuilding is also strongly affected by seasons. It is scoured in shallow water and silted in deep beyond 15 meters. The water depth in the area may be fit and the depth in the further may be predicted by using trend surface fit of two dimension plane with the time series data of measured water depth of 250 m×250 m net grids.