基于MIKE21模型的椒江口台州湾在异常天气下的泥沙输运研究

Study on sediment transport in Taizhou Bay of Jiaojiang Estuary based on MIKE21 model under abnormal weather

目的:研究椒江口台州湾区域在异常天气下的泥沙输运响应规律。方法:建立了异常天气下的椒江口台州湾水动力模型和泥沙数值模型;然后以9711号台风作为异常天气条件,分析了该条件下的椒江口台州湾区域泥沙输运情况。结果:通过计算基本达到了实测含沙量分布水平,悬沙质量浓度变化的模拟值与实测值的变化趋势拟合较好,模型对台州湾水域的悬沙过程能形成比较准确的模拟。结论:在异常天气下该区域含沙量值为正常天气时的3~7倍(平均在4倍以上);异常天气最大浑浊带的峰值与正常天气下相比约多出6倍。正常天气下泥沙移动至口外浅滩处就会沉积或者随潮流向口内运移,而异常天气下泥沙被输运至距离台州湾更远的区域。

Aims: This paper aims to study the sediment transport response law in the Taizhou Bay area of Jiaojiang Estuary under abnormal weather. Methods: The hydrodynamic model and the sediment simulation model of Taizhou Bay in Jiaojiang Estuary under abnormal weather were established. Typhoon No. 9711 was used as the abnormal weather condition;and the sediment transport situation in the Taizhou Bay area of Jiaojiang Estuary under this condition was analyzed. Results: The model simulated well the distribution level of the sediment concentration and the suspended sediment concentration changes with the measured value. The model could form a relatively accurate simulation of the suspended sediment process in Taizhou Bay waters. Conclusions: In abnormal weather, the sediment concentration in this area is 3-7 times of that in normal weather. The peak of turbidity zone in abnormal weather is about 6 times of that in normal weather. In normal weather, sediment moves to the shoal outside the mouth and deposits or moves with the tide to the mouth, while in abnormal weather the sediment is transported to an area farther away from Taizhou Bay.