QUAL2E模型在大沽河干流青岛段水质模拟中的应用

采用QUAL2E模型对大沽河干流青岛段的水质进行了模拟和预测。针对大沽河的具体情况,选用BOD5、COD和氮作为模拟预测指标,用实验模拟方法、模型率定法并参考相关文献确定了BOD耗氧系数k1、BOD复氧系数k2、BOD沉降系数k3、COD耗氧系数和弥散系数等水质参数,并对模拟结果进行了验证,表明预测值和实测值的相关性较好;对BOD5、k1、k2和Q(流量)进行了灵敏度分析,结果表明对大沽河DO浓度影响敏感的参数依次是:Q、k2、BOD、k1,即流量Q是模型最敏感的参数,说明河流的水力学参数对DO影响较大。

Application of QUAL2E model for prediction of water quality of Dagu River

Based on the flow characteristics and pollutant distribution of Dagu River,QUAL2E model,a comprehensive water quality model,was chosen to simulate and predict water quality in the Qingdao section of the main stream of Dagu River, with BOD_5,COD and nitrogen as indexes for simulation and prediction.Some important quality parameters,such as BOD decay coefficient(k_1),reaeration coefficient(k_2),BOD settling coefficient(k_3),COD decay coefficient and dispersion coefficient,were determinated through experimental simulation and by using the model rating method and referring to related literature.The simulation results were verified and showed that the predicted values agreed with the measured ones extremely well.The sensitivity analysis of BOD_5,k_1,k_2,and Q(flux)was also carried out.The results showed that the parameters influencing the concentration of oxygen were lined in the order of Q,k_2,BOD and k_1 in sensitivity.Q is the most sensitive parameter,indicating that hydraulic parameters of the river have a greater influence on DO.The water quality simulation of Dagu River provided basal data for calculating the water environmental capacity of Dagu River and implementing the pollutants total control,as well as scientific evidence for the supervisors and decision-makers of water pollution control.