湖泊纳污能力动态特征分析及计算

Analysis and calculation of dynamic characteristics of lake environmental capacity

受天然因素和人工调控的综合作用,湖泊水文过程和其他自然因子显现出动态变化的特征,这些因子的变化直接影响着纳污能力的动态变化,同时水体污染源也具有明显的时间变化特征。本文分析了湖泊纳污能力的动态特征,提出选择典型水文年和将湖泊与入湖河道作为一个整体进行模拟是进行湖泊动态纳污能力计算的关键。以枯水年作为代表水文年,采用二维数学模型进行太湖纳污能力动态变化的模拟,得到了纳污能力总量和逐月的量值。该研究对提高湖泊水库污染物总量控制的适应性具有一定的意义,也可供河流纳污能力研究进行参考。

Main natural factors of lakes, such as flow, water level and wind are changing with time, which make lake environmental capacity changing with time too. The temporal distribution of pollution load of lakes is also obviously uneven. This paper analyzes the dynamic characteristics of lake environmental capacity by means of numerical simulation. It is proposed to select a typical hydrological year and to define a computational domain, which should cover the lake and all connecting rivers as a whole system for simulation. As a case study, the Taihu Lake system is adopted. A dry year is selected as the typical hydrological year, and a 2-D water quality model is applied. The computation results show the dynamic process of the Taihu Lake, including the total environmental capacity and its monthly values. The study will help to improve the adaptability of total amount control technique in lakes. The basic method can be used as reference for further application in rivers.