【作者】 卢绪川； 李一平； 黄冬菁； 王丽；

【Author】 LU Xu-chuan;LI Yi-ping;College of Environment,Hohai University;

【机构】 河海大学环境学院；

【摘要】 调水引流是改善平原河网水环境污染问题最常用的方法之一,评价不同调水方案的水环境改善效果非常重要。为了评价不同调水引流方案实施后,河网内水环境的变化情况,以太仓城区河网作为研究对象,实施野外原型调水实验,建立了一维非稳态河网水量水质数学模型,并利用野外监测得到的水文、水质数据对模型进行率定验证。模拟计算了各方案实施后河网区水体COD和氨氮浓度的变化情况和换水面积。将城区河网分成4部分,选取各部分河网的换水率及8个重点监测断面的COD和氨氮浓度改善程度为评价指标。以选取的20个评价指标构建水环境变化情况评价指标体系,采用主成分分析法对评价指标进行降维处理,建立水环境改善驱动因子的多元线性回归模型,提取COD改善程度、氨氮改善程度和换水面积率3子系统的主成分,并用熵值法对子系统赋权,最后计算水环境改善程度综合得分并进行分析评价。结果表明:(1)调水引流实施后,太仓市主城区河网水质有明显改善,COD改善程度子系统权重最高。(2)改善效果受引排水口分布、引水流量和引水水质的共同影响,并不随引水流量的增加而增加。(3)通过主成分分析和熵值法联合有利于评估和优化调水方案的效益,可为制定调水引流方案提供依据。更多还原

【Abstract】 Water transfer and diversion is one of the most common method to improve aquatic environmental pollution in plain river network areas.Therefore,the evaluation of different water transfer plans is essential for the effect of aquatic environmental improvement.For the purpose of evaluating the variations of aquatic environment in river networks after these plans’ implement,we took the river networks in Taicang city district as research object.An experience with a simulated prototype on field is carried out,based on which a one dimension unsteady river network mathematical modeling is established,a calibration is also conduct with hydrological and water quality data collected on field.The variations on COD and ammonia-nitrogen is calculated by simulation following each plan’s implement.We can get the ratio of water exchange area and the COD improving extent within 8 highly concerned monitoring sections,as well as the ammonia-nitrogen improving extent.Using the 20 selected indicators,an evaluation system of the state of aquatic environmental variation is built.More precisely,we employed the principal component analysis to reduce the dimension of these evaluating indicators,and established a multiple linear regression model of the driving factors which improve aquatic environment.Then all the principal components acting on COD improvement,ammonia-nitrogen improvement and water exchange area ration are extracted.As a result,a comprehensive score on water environmental improvement can be calculated and analyzed after determining different weight of each sub-system with entropy method.The results indicate that:(1) The water quality has significantly improved following water transfer and drainage,the COD improvement subsystem has the highest weigh;(2) The improving effect is co-influenced by the distribution of water diversion and output points,the flow of diversion,and the quality of the drawing water,besides,it doesn’t increase straightly with the flow of diversion turning bigger;(3) The principal component analysis and the entropy method is beneficial for the assessment and improvement of water transfer plans’ effect,providing supports for establishing water transfer and diversion plan.更多还原