扩散作用对静水湖泊水质浓度空间分布的影响

根据水域开阔的中小型浅水湖泊的水动力特征,建立了加入扩散项的湖泊移流模式,分析了污染物对流输移、降解作用、扩散作用对污染物浓度空间分布的影响。研究发现:在静风条件下,对流输移、降解作用是湖泊水质浓度空间分布的主要影响因素,扩散作用对湖泊水质浓度空间分布的影响居次要地位。但当排污流量较小且污染物浓度较高时,扩散作用对预测结果有一定的影响。在进行湖泊水质空间分布精确预测时,应综合考虑对流输移、降解及扩散作用等因素的综合影响。

Influence of diffusion on spatial distribution of water quality concentration in stagnant lake

According to the hydrodynamic characteristics of wide shallow lakes of middle and small scale, a drifting mode coupled with diffusion item was established and used to analyze the effect of the convective transportation, degradation and diffusion of the pollutants on their distribution. It shows that under the windless condition, the convective transportation and degradation are the major factors affecting the spatial distribution of contaminant concentration, while the diffusion is the minor one. But the diffusion contribution has certain effects on the prediction results when the sewage discharge is small and the pollutant concentration is high. The effects of the convective transportation, degradation and diffusion should be considered comprehensively in the prediction of spatial distribution of water quality of lakes.