澜沧江漫湾大坝对水体氮磷迁移及形态的影响  

Influence of Manwan Dam on Transportation and Speciation of Nitrogen and Phosphorus in Water of Lancang River

作　　者：张萌 张银烽[1,2] 杨鸿锋 张真 任桃艳 王婷凤[1,2] ZHANG Meng;ZHANG Yin-feng;YANG Hong-feng;ZHANG Zhen;REN Tao-yan;WANG Ting-feng(Yunnan Key Laboratory of Plateau Wetland Conservation,Restoration and Ecological Services,College of Wetlands,Southwest Forestry University,Kunming 650224,China;National Plateau Wetland Research Center,Southwest Forestry University,Kunming 650224,China)

机构地区：[1]西南林业大学湿地学院/云南省高原湿地保护修复与生态服务重点实验室,昆明650224 [2]西南林业大学国家高原湿地研究中心,昆明650224

出　　处：《科学技术与工程》2022年第30期13578-13589,共12页Science Technology and Engineering

基　　金：云南省科学技术厅青年基金(2019FD077)。

摘　　要：筑坝形成的蓄水河流在中国普遍存在,相应的生态环境影响是国内外研究热点。探究筑坝行为对河流营养元素分布,形态及迁移影响能够为科学筑坝提供理论支撑。因此,为了解澜沧江流域的筑坝行为对该流域水体氮磷的影响,选择澜沧江流域典型的漫湾水电站及其上下游不受支流干扰的河段作为研究区域,分季节采集194个水体样品,分析漫湾大坝对该区域水体氮磷空间分布,形态及迁移影响。结果表明:漫湾大坝不同季节下游水体总氮(total nitrogen,TN)浓度均明显低于上游水域(P<0.05),表明筑坝对河流总氮具有一定拦截作用,平水期(10月)和枯水期(4月)氮拦截率分别为15%、16%,丰水期(7月)仅6%;氮形态数据表明筑坝影响水体中氮形态的分布。具体表现为漫湾大坝上下游水体中氮元素以硝态氮为主,但筑坝对硝态氮的拦截作用不明显(P>0.05)。对铵态氮则有明显的拦截作用(P<0.05),平水期和枯水期大坝能够拦截河流水体中部分有机氮(P<0.05);枯水期和丰水期上、下游水体总磷(total phosphorus,TP)浓度无显著性差异(P>0.05),相较而言漫湾大坝只在平水期能够拦截少量磷;水体TN与TP显著正相关,表明其具有同源性。除此之外大坝上下游水体中氮的分布也受叶绿素、氧化还原电位、溶解氧等水体理化指标的影响。The impoundment-rivers caused by dam-building are ubiquitous in China,and the corresponding environmental effects have attracted much attention all over the world.The investigations in the influence of dam-building on the distribution,speciations and transportation of nutrient elements in rivers can provide theoretical support for scientific damming.To understand the effects of dam-building on aquatic nitrogen and phosphorus in Lancang River,Manwan Hydropower Station in Lancang River and its upstream and downstream river were selected as the study area.Seasonal aquatic samples of 194 were collected and determined to evaluate the effects of Manwan dam on distribution,speciations and transportation of nitrogen and phosphorus.The results show as follows.The concentrations of total nitrogen(TN)in the downstream area were significantly lower than those of upstream area(P<0.05),indicating that the dam had a certain interception effect on total nitrogen,and nitrogen interception rates in the normal period(October)dry season(April)were 15%and 16%,while the interception rate was only 6%in rainy season(July).Speciations of nitrogen demonstrated that dam-building affected distribution of speciaitons of nitrogen.Although interception effect for nitrates was not obvious(P>0.05),nitrates were the dominant species along the whole river.However,obvious interception effect for ammonium was observed(P<0.05)and similar effects were observed for organic-nitrogen in normal period and dry season(P<0.05).There were no significant differences in total phosphorus(TP)between the upstream and downstream area during the dry and wet periods(P>0.05),but slight interception effects for phosphorus were observed in normal period.The TN and TP are significantly positively correlated along the whole river,indicating that they may share the same sources.In addition,the distributions of nitrogen in water were also affected by physicochemical indicators including chlorophyll-a(Chl-a),oxidation-reduction potential(ORP)and dissolved oxygen.

关 键 词：漫湾大坝 氮 磷 澜沧江 

分 类 号：X522[环境科学与工程—环境工程]