三峡库区悬沙颗粒磷的粒径变化和滞留特征  

Particle size variation and retention characteristics of phosphorus in suspended sediments in Three Gorges Reservoir Area

作　　者：陈晴空[1,2,3] 陈治君 王殿常 兰峰 高千红 李姗泽 CHEN Qingkong;CHEN Zhijun;WANG Dianchang;LAN Feng;GAO Qianhong;LI Shanze(Chongqing Engineering Laboratory of Environmental&Hydraulic Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Joint Graduate Training Base of Resources and Environment between Chongqing Jiaotong University and Chongqing Gangli Environmental Protection Co.,Ltd.,Chongqing Jiaotong University,Chongqing 400074,China;Yangtze Eco-Environment Engineering Research Center,China Three Gorges Corporation,Wuhan 430014,Hubei,China;Yangtze Ecology and Environment Co.,Ltd.,Wuhan 430062,Hubei,China;Upper Changjiang River Bureau of Hydrological and Water Resources Survey,Hydrology Bureau of Changjiang Water Resources,Chongqing 400020,China;Three Gorges Bureau of Hydrological and Water Resources Survey,Hydrology Bureau of Changjiang Water Resources,Yichang 443008,Hubei,China;State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin,China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]重庆交通大学环境水利工程重庆市工程实验室,重庆400074 [2]重庆交通大学重庆交通大学-重庆港力环保股份有限公司资源与环境研究生联合培养基地,重庆400074 [3]中国长江三峡集团有限公司长江生态环境工程研究中心,湖北武汉430014 [4]长江生态环保集团有限公司,湖北武汉430062 [5]长江水利委员会水文局长江上游水文水资源勘测局,重庆400020 [6]长江水利委员会水文局长江三峡水文水资源勘测局,湖北宜昌443008 [7]中国水利水电科学研究院流域水循环模拟与调控国家重点实验室,北京100038

出　　处：《水利水电技术(中英文)》2025年第1期181-192,共12页Water Resources and Hydropower Engineering

基　　金：国家自然科学基金项目(51809287);中国长江三峡集团有限公司项目(202003173);第八届青托工程项目(2022QNRC001);重庆市研究生联合培养基地项目(JDLHPYJD2022005)。

摘　　要：【目的】磷是长江的主要污染物和生源要素,三峡大坝的建成导致大量携带磷的悬沙(颗粒磷)被拦截而影响长江流域的生态环境。粒径(D)是悬沙的重要物理特性,但目前对长江颗粒磷的研究缺乏粒径方面的信息。【方法】2021年在三峡库区长江干流和支流嘉陵江、乌江的8个水文断面逐月开展了悬沙粒径级配分析和各粒径段悬沙含磷量(PP′)的监测,获得了各断面不同时间、不同粒径段悬沙的PP′值,输沙率和流量、流速等水文参数以及总磷(TP)、溶解态磷(DP)、颗粒磷(PP)的浓度,总结了库区悬沙粒度特征和含磷量的时空变化规律并分析了库区中主导颗粒磷输移的主要悬沙成分,估算了库区对不同悬沙成分的拦截作用。【结果】结果显示:(1)库区悬沙以D≤0.062 mm的细颗粒为主,从上游到下游有细化趋势;粉砂通量最大可占全年D≤0.062 mm悬沙通量的77%,粉砂颗粒磷通量最大可占全年D≤0.062 mm悬沙颗粒磷通量的82%,粉砂是库区颗粒磷的主要载体。(2)非汛期库区长江干流各粒径段的悬沙平均含磷量大于汛期,且粒径越小PP′值越大,但汛期却是0.002<D<0.004 mm的黏粒含磷最多,输沙率决定悬沙通量的多少,是影响颗粒磷输移的主要因素。(3)库区水体中的磷在非汛期以DP为主,汛期以PP为主,全年都有悬沙和PP滞留,尤以汛期为主,汛期悬沙和颗粒磷滞留量分别约占全年滞留量的94.5%和97.1%;粉砂颗粒磷在库区的滞留率>80%,黏粒颗粒磷的滞留率>60%。【结论】结果表明:悬沙粒径级配与土壤测磷相结合的监测方法能明确库区不同粒径悬沙的含磷量,为库区磷监测提供新的技术参考;库区悬沙成分占比对颗粒磷输移的影响大于悬沙粒径,悬沙成分占比越大,对颗粒磷输移的影响越大,因此长江上游控磷更应侧重对悬沙成分占比方面。[Objective]Phosphorus is the main pollutant and biogenic element in the Yangtze River,and the completion of the Three Gorges Dam has led to the interception of a large number of suspended sediment(particulate phosphorus)carrying phosphorus,which has affected the ecological environment of the Yangtze River Basin.Particle size(D)is an important physical property of suspended sediment,but there is a lack of information on particle size(D)in the study of particulate phosphorus in the Yangtze River.[Methods]Suspended sediment particle size gradation analysis and suspended sediment phosphorus content(PP′)monitoring were carried out monthly in eight hydrological sections of the Yangtze River mainstream and its tributaries Jialing River and Wujiang River in the reservoir area in 2021,and the PP′values of suspended sediment at different time and different particle size sections were obtained.Sediment transport rate,flow velocity and other hydrological parameters,as well as total phosphorus(TP),dissolved phosphorus(DP)and particulate phosphorus(PP)concentrations,the temporal and spatial variation of suspended sediment particle size characteristics and phosphorus content in the reservoir area were summarized,the main suspended sediment components dominating the transport of particulate phosphorus in the reservoir area were analyzed,and the interception effect of the reservoir area on different suspended sediment components was estimated.[Results]The results show that:(1)The suspended sediment in the reservoir area was dominated by fine particles with D≤0.062 mm,and there was a trend of refinement from upstream to downstream.Silt is the main carrier of particulate phosphorus in the reservoir area,accounting for 77%of the annual suspended sediment flux(D≤0.062 mm)and 82% of the annual suspended sediment flux(D≤0.062 mm).(2)The average phosphorus content of suspended sediment in each section of the Yangtze River mainstream in the non-flood season is greater than that in the flood season,and the smaller the particle s

关 键 词：三峡库区 悬沙 粒径 颗粒磷 滞留率 时空变化 水质 

分 类 号：X524[环境科学与工程—环境工程]