近岸水域中污染羽流的运动及访问频率场模型

A MODEL FOR PREDICTING MOTION AND VISITATION FREQUENCY OF CONTAMINANT PLUMES IN COASTAL WATERS

本文研究了由污水排海工程污水扩散器排放污水形成的污染羽流在近岸水域中的运动及访问频率场模型。在对Churchill羽流运动模拟法改进的基础上,提出了羽流分片模拟法。本方法利用质量守恒原理给出了其变化关系,并采用连续释放质点追踪法计算羽流的运动路径。考虑到非保守性物质的衰减,给出了相应的计算羽流宽度的公式。对大连市黑石礁污水排海工程方案A污染羽流(以大肠杆菌作为污染指标物)访问频率场的计算表明:访问频率场对于污水排海工程环境影响预测评价和最优排污点的选择具有十分重要的意义。

In this paper, the models for predicting motion and visitation frequency of the contaminant plumes emanating from the diffuser of the sea outfall in coastal waters are examined. Based on the improvement of the Churchill's plume motion simulation method, a plume segment simulation method is presented. The model considers the variation of the distribution density of the contaminant substance and gives its variation relation by means of the mass conservation principle. According to the transfer relationship between the Eulerian field and the Lagrangian field, the path of the plume is estimated by using the continuous release particle tracking method. The decay of the non-conservative substance is also considered in this paper, and the equation of estimating the plume width is given. The numerical examples for the Alternative A of the sea outfalls in Heishijiao Bay, Dalian, show that the visitation frequency field is a significant tool in assessing of the environment effects and in selecting the optimal discharge site of the sea outfall.