海南岛博鳌港洪水过程模拟

Simulation of Flooding Processes in Boao Harbour, Hainan Island

采用一个包括陆地淡水径流和风暴潮影响的模型计算了海南省博鳌港的洪水水位。模型中的外海潮汐考虑 K1和O1分潮,风暴增水和河流流量的变化过程采用峰值函数的形式模拟,取得了与实测结果相近的计算结果。模拟实验表明,洪水水位峰值与河流洪峰流量,风暴增水峰值,系统的过水断面形状以及洪水历时的长短等因素有关。对于博鳌港口门通航条件整治,采用复合的梯形过水断面最为合适,因为相对于天然的口门过水断面,复合梯形断面能使湾内的最高洪水水位下降约 20 %。

A numerical model is established to predict flooding characteristics in response to freshwater discharge and storm surge events, for the Boao Harbour, Hainan Island. The K1 and O1 tidal constituents are included to generate spring-neap tidal cycles, and two peak-value functions are used to stimulate typical freshwater discharge and storm surge processes. There is a good agreement between the computed and observed water levels. Numerical experiments show that the basin water level can be defined using the ratio of freshwater discharge to storm surge intensity, and the highest water level during a flooding event is controlled by the peak runoff, water level rise due to storm surge, the configuration of inlet throat cross-section and the duration of the flooding event. In order to improve the navigation and flood prevention conditions of the harbour, a combined trapezoid-shaped cross-section may be adopted, which can reduce the flooding water level within the harbour by 20 %, as compared with the value associated with a natural cross- section at the entrance channel.