上游大通径流量对长江盐水入侵影响研究

The Research on the Influence of the Change of River Discharge at Datong on the Saltwater Intrusion in Yangtze Estuary

建立二维盐度数值模型,计算区域包括大通至长江口及其邻近海域,设计高分辨率网格,数值模拟和分析在不同大通流量等级下长江口盐水入侵形势,计算出中小潮期间长江口重要水库取水口处盐度均值为0.5‰时对应的临界大通流量。利用模型分析长江口盐度场对上游大通流量的敏感性。本文对临界大通流量的计算研究有助于提高预报长江口盐水入侵模型精度,为长江口水库避咸蓄淡提供参考;盐水入侵对流量的敏感性研究可以为改善盐水入侵情况提供技术指导。

Applying the 2D numerical model with high resolution grid,the response of saltwater intrusion in the Yangtze estuary to the change of river discharge at Datong is studied. The calculated domain of the model includes the lower reaches of the Yangtze River from Datong to the Yangtze Estuary and its adjacent sea. Using the model,the critical discharge of Datong corresponding the average salinity of 0. 5‰ at important reservoirs＇ water inlets is calculated in different tidal pattern. The sensitivity of Yangtze estuary salinity field to the change of upstream discharge is analyzed using the model. The critical chase flow computing research helps to improve the precision of the Yangtze estuary saltwater intrusion model prediction,providing a reference for Yangtze estuary avoiding salty for the storage of reservoir. Saltwater intrusion in the discontinuous flow downstream of the sensitivity of the research improve estuary salt water intrusion is to the research on the sensitivity of Yangtze estuary salinity field to the change of upstream discharge can provide technical guidance to avoiding saltwater intrusion at Yangtze estuary in dry seasons.