洞庭湖出入湖氮磷通量特征及滞留效应研究  

Characteristics analysis and retention effect of phosphorus and nitrogen fluxes in Dongting Lake

作　　者：赵子豪 袁静 田泽斌[1] 储昭升[1,2] 汪星 ZHAO Zihao;YUAN Jing;TIAN Zebin;CHU Zhaosheng;WANG Xing(National Engineering Laboratory for Lake Pollution Control and Ecological Restoration,State Environment Protection Key Laboratory for Lake Pollution Control,Chinese Research Academy of Environmental Sciences,Beijing 100012,China;Key Laboratory of Poyang Lake Environment and Resources Utilization,Ministry of Education,School of Resources&Environment,Nanchang University,Nanchang 330031,China)

机构地区：[1]中国环境科学研究院,湖泊水污染治理与生态修复技术国家工程实验室,国家环境保护湖泊污染控制重点实验室,北京100012 [2]南昌大学资源与环境学院,鄱阳湖环境与资源利用教育部重点实验室,江西南昌330031

出　　处：《水资源与水工程学报》2023年第3期74-82,共9页Journal of Water Resources and Water Engineering

基　　金：国家重点研发计划项目(2021YFC3201003);三峡工程运行对洞庭湖水环境影响及保护技术研究项目(2017HXXY-05)。

摘　　要：采用2013—2017年洞庭湖主要出入湖断面水质、水量监测数据,估算洞庭湖经由“四水”(湘江、资水、沅江、澧水)和长江“三口”(松滋口、太平口、藕池口)入湖及城陵矶出湖氮、磷通量,分析其时空变化特征及滞留效应。结果表明:时间上,2013—2016年“四水”“三口”年均入湖氮、磷通量总体呈增加趋势,但2017年受入湖水质改善、水量减小的同步影响,相比2016年入湖氮、磷通量分别减小了19.93%、23.14%,受水情影响,入湖氮、磷通量在年内分配不均,70%以上集中在4—9月;空间上,入湖氮、磷通量主要来源于“四水”水系,分别占78.48%和71.77%,其中湘江和沅江的贡献较大。“四水”受点、面源污染的综合作用,而“三口”的面源污染是其主要污染来源。此外,洞庭湖氮、磷滞留率很低,藻类浓度不高,但湖区氮、磷浓度(1.73、0.075 mg/L)仍远高于湖泊藻类暴发的临界值(0.20、0.02 mg/L)。为降低湖泊水华的发生风险,关键是保持湖泊的连通性,警惕长江“三口”区域总磷风险,并兼顾湖滨区污染物控制。Based on the hydrological and water quality data in the main monitoring sections of Dongting Lake from 2013 to 2017,influxes of TN and TP from the four upstream branches(Xiang River,Zi River,Yuan River and Li River)and three water inlets(Songzi,Taiping and Ouchi)of Dongting Lake,as well as the outflux of Chenglingji outlet were estimated to analyze the spatio-temporal characteristics and retention effect of the two pollutants.The results show that the annual nitrogen and phosphorus fluxes into Dongting Lake showed an overall increasing trend during 2013-2016;but in 2017,influenced by the synchronous change of water quality and water quantity,the nitrogen and phosphorus influxes decreased by 19.93%and 23.14%,respectively,compared with 2016.Controlled by seasonal variation of water quantity,the nitrogen and phosphorus influxes distributed unevenly in the year,with more than 70%from April to September.In terms of spatial distribution,the nitrogen and phosphorus influxes mainly came from the four upstream branches,accounting for 78.48%and 71.77%,with the greatest contribution from the Xiang and Yuan Rivers.The four upstream branches were affected by the comprehensive effect of point and non-point source pollution whereas the three water inlets were mainly influenced by non-point source pollution.Apart from these,pollutant retention rate of these two pollutants in Dongting Lake were low,so the concentration of phycophyta was not high,but the nitrogen and phosphorus concentrations in the lake(1.73 and 0.075 mg/L)were still much higher than the critical value of algae outbreak(0.2,0.02 mg/L).In order to reduce the risk of water bloom,it is vital to maintain the connectivity of the lake,pay attention to the risks of TP in the three water inlets and the control of pollutants around the lake.

关 键 词：氮、磷污染物 污染物通量 滞留效应 污染物控制 湖泊水华 洞庭湖 

分 类 号：X524[环境科学与工程—环境工程]