基于DEM的南黄海辐射沙脊群冲淤演变初步研究

The study of scouring and silting evolution of radiative sand ridge filed of the South Yellow Sea in support of DEM

利用1968年(实测时间为1963-1968年)和1979年南黄海辐射沙脊群三丫子港至川腰港1:200000海图以及2006年大丰港及其附近1:50000海图资料,用Mapinfo进行数字化处理,得到水深点和等深线数据,在Surfer8.0中进行Kriging插值,分别建立水下数字高程模型(DEM),并定量计算1968年至1979年三丫子港至川腰港的冲淤变化,以及西洋潮流通道1968年、1979年和2006年之间的冲淤变化。结果表明:①辐射沙脊群三丫子港至川腰港1968年至1979年全区处于冲淤动态平衡,冲刷量为8.98×109m3,淤积量为11.38×109m3。全区平均淤高13cm/a,年均淤积速率为1cm,其中以沿岸和东北部淤积为主,沙脊群中心枢纽部位冲淤变化较为频繁,外海大部分区域较为稳定。②西洋潮流通道1968年至1979年以冲刷为主,全区平均冲刷1.05m,年均冲刷速率为8.0cm/a;1979年至2006年仍以冲刷为主,全区平均冲刷1.59m,但年均冲刷速率小于1968年至1979年,为5.9cm/a。

2 pieces of charts of radiative sand ridge filed of the South Yellow Sea from 1968 to 1979 and 1 piece of chart of Xiyang tidal channel from 1979 to 2006 are digitized and the digital elevation model （DEM） in different periods are established with Kringing gridding method by using the software of Mapinfo and Surfer. The calculation of the volume of scouring and silting shows that： the scouring and silting evolution of radiative sand ridge filed of the South Yellow Sea is in the instance of homeostasis. The volume of scouring being 8.98×10^9m^3, and the volume of silting being ll.38×10^9m^3. The height of silting of the total area being 13 cm, and the mean volume of annual silting being 1 cm/a. It is showed that Coastwise and northeast of the radiative sand ridge filed being silting, and the variation of the hinge of radiative sand ridge is frequent, and the most part of the outside sea is stable. ② It is concluded that the Xiyang tidal channel was characterized by scouring from 1968 to 1979. The height of scouring being 1.05 cm, and the mean volume of annual scouring being 8.0 cm/a. It is still characterized by scouring from 1979 to 2006. The height of scouring being 1.59 cm, and the mean volume of annual scouring being 5.9 cm/a.