运用EFDC模型构建鄱阳湖水利枢纽工程与主湖区的二维模型,使用Delft3D软件划分研究区域网格,并以2010年实测TIN、TP数据为初始条件,模拟水利枢纽运行前后湖区氮磷营养盐的变化特征,验证结果显示TIN和TP的计算值和实测值吻合较好,证明了模型计算结果的有效性和可靠性。结果表明:水利枢纽运行后,枯水期湖区TIN、TP浓度分别增长20.42%和20.55%,达到2.86和0.44mg/L,饶河是湖区污染物的主要来源;平水期湖区TIN、TP浓度分别增长13.39%和12.90%,达到2.08和0.18mg/L,赣江主支与修河的汇流是湖区污染物的主要来源,枢纽对氮磷的影响主要体现在对磷素的控制上;在以松门山为界的南、北湖区,TIN表现出北湖区〉南湖区,TP为南湖区〉北湖区的变化特征;湖区N/P比值为9.27,比实测值低2.91%,磷素污染较重。
Abstract: Based on the EFDC model, a two dimensional model for hydro-junction projects and main basin of Poyang Lake is established. Study area is divided with Delft3D method,TIN and TP data in 2010 are the in- itial condition, and the change characteristics of nitrogen and phosphorus nutrients before and after operat- ing the hydro-junction are imitated. The verification result shows that the calculated values of TIN and TP are coincide with the measured values, which also prove that the calculated values of model are efficient and reliable. The concentration of TIN and TP have a growth of 20.42% and 20.55% in dry season after oper- ating the hydro-junction, and the value are 2.86 mg/L and 0. 44 mg/L, respectively. Raohe River is the main source of regional pollutants. The increasing rate of TIN and TP are 13.39% and 12.90% in flat wa- ter season, and the concentration are 2.08 mg/L and 0.18 rag/L, respectively. Pollutants in lake region mainly come from the confluence of Gan River main branch and Xiuhe River, and the impacts of hydro-junc- tion on nitrogen and phosphorus is mainly reflected in the control of phosphorus. In southern and northern lake regions, the values of TIN in northern lake regions are higher than that in southern lake regions, while the value of TP in southern lake regions is higher than that in northern lake regions. Ratio of N/P in Poy- ang Lake district is 9.27, 2.91% lower than the measured value,indicating that the pollution degree of phosphorus is heavy.