季冻区农药化肥施用的湖泊富营养化响应  

Investigation on lake eutrophication response to pesticide and fertilizer application in the seasonal freeze region

作　　者：楼雨奇 卞建民 孙晓庆 王宇 王凡 李慕蓉 LOU Yu-qi;BIAN Jian-min;SUN Xiao-qing;WANG Yu;WANG Fan;LI Mu-rong(Key Laboratory of Groundwater Resources and Environment Ministry of Education,College of Environment and Resources,Jilin University,Changchun 130021,China)

机构地区：[1]吉林大学新能源与环境学院,地下水资源与环境教育部重点实验室,吉林长春130021

出　　处：《中国环境科学》2023年第S1期301-308,共8页China Environmental Science

基　　金：吉林省科技重大科技专项(20230303007SF);国家自然科学基金(42272299);吉林省自然科学基金(20220101173JC);吉林省教育厅项目(JJKH20231180KJ)

摘　　要：为探究中国北方季冻区湖泊富营养化及驱动因素,以吉林省西部查干湖为研究对象,利用监测数据,应用BP神经网络模型,开展湖泊富营养化现状评价,识别超限营养指标,并分析其动态特征;采用EQC多介质模型,评估灌区排水中残余农药化肥等对水环境的影响,探讨湖泊富营养化状态的驱动因素.结果表明:2016-2019年,湖泊水质总体为轻度富营养化,主要超限营养指标为COD_(Mn)、COD_(Cr)、TP和TN等.超限指标COD_(Mn)、COD_(Cr)和TP受低温驱动,在冰封期浓度呈上升趋势,其中,湖泊TP浓度上升约10%.受灌排驱动,在灌区退水期TP和TN呈现上涨趋势.通过EQC模拟,获得灌区排水进入湖泊的TN和TP浓度贡献值,分别为2.717、0.080mg/L,灌区退水中残留的农药化肥组分入湖,是驱动退水期湖泊TN含量上升的主要因素,最大上升比例约27%.低温是冰封期湖泊总磷浓度上升(最大上升约10%)的主要驱动因素.加之春季农药化肥施用对湖泊夏季富营养化程度的影响,导致季冻区湖泊在冬夏两季呈现富营养化加剧趋势.研究区湖泊富营养化治理仍需重点关注灌区退水期外源污染中化肥的削减措施.To investigate the eutrophication and driving factors of lakes in the frozen region of northern China,the study takes Lake Chagan in western Jilin Province as the research object.Based on monitoring data,the Back Propagation(BP)neural network has been systematically applied to evaluate the eutrophication of lake and the excess nutrient indicators have been identified to analyze their dynamic characteristics.After that,the EQC model has been used to simulate the influence of water from pesticide and fertilizer residues in irrigation drainage and explore the drivers of the lake eutrophication.The results showed that:During 2016~2019,the lake was generally mildly eutrophic,with the main excess nutrient indicators being COD_(Mn),COD_(Cr),TP and TN,etc.The concentration of COD_(Mn),COD_(Cr) and TP were driven by low temperatures and showed an increasing trend during the freezing period,among them,the concentration of TP increased 10%,approximately.Meanwhile,the concentration of TP and TN,were driven by irrigation and drainage that showed an upward trend during the receding irrigation period.Through EQC simulation,the contribution values of TN and TP concentrations of irrigation area drainage into the lake were obtained as 2.717mg/L and 0.080mg/L,respectively.The residual pesticide and fertilizer from the irrigation drainage were the main factors driving the increase of the TN content in the lake during the receding period,with a maximum rise of 27%.Low temperatures were the main driver of the increase of the TP content in the lake during the freeze-up period(maximum increase of about 10%).Meanwhile,the application of pesticides and fertilizers in spring has led to a trend of increased eutrophication in the lakes of the seasonal freeze region during the winter and summer.In conclusion,the management of lake eutrophication still needs to focus on reducing exogenous pollution,especially fertilizer pollution,during the receding period of the irrigation area.

关 键 词：灌溉排水 农药化肥 季冻区湖泊 富营养化 多介质模型 BP神经网络 

分 类 号：X524[环境科学与工程—环境工程]