三维多组分泥沙数值模型在胶州湾的应用

基于环境流体动力学模型(Environmental Fluid Dynamics Computer Code EFDC)水动力和泥沙模块,把底床泥沙分为1个黏性组分和4个非黏性组分,建立起一个多组分泥沙三维胶州湾数学模型。模型很好地反演了胶州湾三维水动力场和悬沙浓度场。结果表明,在潮流作用下,胶州湾水体中悬沙浓度较小,以黏性组分(<0.063 mm)为主。悬浮起来的黏性组分泥沙随着潮流的涨落,在湾内外作长距离往复运动。可悬浮的非黏性泥沙(0.063~0.25 mm)基本上集中在湾外水体底层,表现为局部悬移,就近落淤。胶州湾总体上冲淤变化幅度较小。内湾以冲刷为主,局部淤积;外湾基本上呈淤积状态;湾外冲淤形式较为复杂。

A 3D MATHEMATIC MODEL FOR MULTI-COMPONENTS SEDIMENTS AND ITS APPLICATION IN JIAOZHOU BAY

Based on the hydrodynamic and sediment transport module of the Environmental Fluid Dynamics Code (EFDC), we developed a 3D mathematic model for calibration and verification of hydrodynamic process, sediment resuspension and transportation of the multi-components sediments of the Jiaozhou Bay. In the model, bottom sediments were divided into one cohesive and four noncohesive classes. The results indicate that the concentration of tidal-driven suspended sediment was relatively low and thus cohesive sediments (<0.063mm) predominated in the water body of JZB. The suspended cohesive sediments move mainly with tide in a reciprocating way of long distance within the bay. However, most of the suspended noncohesive sediments (0.063~0.25mm) fell rapidly and accumulated at the sea bottom off the bay. In general, the changes in the sedimentation pattern of the entire JZB were not significant. The inner Bay has mainly been erosional with a relatively small rate of sedimentation while the outer Bay remained in deposition. But, the sedimentation pattern is relatively complex in the outside of JZB.