千岛湖水体营养盐时空变化及水环境挑战  

Spatio-Temporal Variation of Nutrient Concentrations and Environmental Challenges of Qiandaohu Reservoir,China

作　　者：朱广伟[1] 程新良 吴志旭 史鹏程 朱梦圆[1] 许海[1] 国超旋 赵星辰 ZHU Guangwei;CHENG Xinliang;WU Zhixu;SHI Pengcheng;ZHU Mengyuan;XU Hai;GUO Chaoxuan;ZHAO Xingchen(Qiandaohu Ecosystem Research Station,Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences,Nanjing 210008,China;Hangzhou Bureau of Ecology and Environment,Chun'an Branch,Hangzhou 311700,China)

机构地区：[1]中国科学院南京地理与湖泊研究所千岛湖生态系统研究站,江苏南京210008 [2]杭州市生态环境局淳安分局,浙江杭州311700

出　　处：《环境科学研究》2022年第4期852-863,共12页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.41830757);中国科学院野外站联盟项目(No.KFJ-SW-YW036);杭州市生态环境局淳安分局委托项目(No.CAZFCGGK2020-1)。

摘　　要：为揭示亚热带深水水库水环境变化特征及其驱动力,于2020年5月—2021年4月在千岛湖布设100个监测点,开展了为期1年的逐月水环境调查,分析营养盐时空分布特征及水质风险.结果表明:千岛湖水体总氮(TN)、总磷(TP)、叶绿素a(Chla)、浮游植物生物量(PB)等关键水环境指标时空差异大,全库年均TN浓度为0.92 mg/L,其中月均最大值出现在3月,为1.04 mg/L,最小值出现在8月,为0.78 mg/L,安徽段库区年均值为1.60 mg/L,而东南库湾年均值为0.83 mg/L;全库年均TP浓度为0.021 mg/L,其中月均最大值出现在7月,为0.033 mg/L,最小值出现在11月,为0.013 mg/L,安徽段库区年均值为0.052 mg/L,而东南库湾年均值为0.015 mg/L;全库年均Chla浓度为5.1μg/L,其中月均最大值出现在7月,为10.0μg/L,最小值出现在11月,为1.6μg/L,安徽段库区年均值为11.4μg/L,而东南库湾年均值为3.0μg/L;全库全年Chla浓度最大层PB平均值为2.396 mg/L,月均最大值为8.246 mg/L(8月),最小值为0.557 mg/L(11月);在空间上,PB最高值出现在城中湖,年均值为3.688 mg/L,最低值出现在西南库湾,年均值为1.740 mg/L.尽管千岛湖部分水质断面能阶段性保持贫营养水平,但较大比例水域已处于中营养,且在时间上存在不稳定性,暴雨入库期全库TP平均值可达枯水期的3倍,不同月份PB差异可达15倍,表明千岛湖水质的稳定达标存在较大挑战.在大型深水水库中,气象水文过程对局部库湾水环境指标的冲击较大,藻类对外源负荷入库产生明显放大作用,在水库水环境保护中应将外源负荷控制作为水质风险防控的关键,并重视水库生态系统结构的调控,防控蓝藻和硅藻等水华优势属藻类的过度增殖.In order to understand the changing characteristics and drivers of environmental indicators in subtropical deep reservoirs,a oneyear monthly 100-point survey of nutrient concentrations and water quality risks in Qiandaohu Reservoir was undertaken from May,2020 to April,2021.It was found that the water quality parameters such as total nitrogen(TN),total phosphorus(TP),chlorophyll a(Chla)and phytoplankton biomass(PB)were significantly different.The annual average TN of the whole lake was 0.92 mg/L,with the highest value of 1.04 mg/L in March,and the lowest value of 0.78 mg/L in August.The Anhui section of the reservoir had the highest annual average TN of 1.60 mg/L,and the lowest TN of 0.83 mg/L in the southeast bay.The annual average TP of the whole lake was 0.021 mg/L,with the highest value of 0.033 mg/L in July,and the lowest value of 0.013 mg/L in November.The Anhui section of the reservoir had highest yearly average TP of 0.052 mg/L,and the lowest TP of 0.015 mg/L in the southeast bay.The annual whole lake average Chla was 5.1μg/L,with the highest value of 10.0μg/L in July,and the lowest value of 1.6μg/L in November.The Anhui section of the reservoir had the highest annual average Chla of 11.4μg/L,and the lowest Chla of 3.0μg/L in the southeast bay.The annual whole lake average PB was 2.396 mg/L,with the highest value of 8.246 mg/L in August,and the lowest value of 0.557 mg/L in November.The Chun’an urban bay of the reservoir had the highest annual average PB of 3.688 mg/L,while the lowest PB of 1.740 mg/L in the southwest bay.Although the downstream part of Qiandaohu Reservoir was in an oligotrophic state,a major part of the reservoir was already in a meso-trophic state.The important water parameters were temporarily unstable.The TP concentration in the flood season was 3 times higher than that in the dry season.PB concentration in August was on average 15 times higher than that in November.The annual survey indicates that it is a huge challenge to maintain stable good water quality.As a huge deep rese

关 键 词：大型深水水库 富营养化 浮游植物 磷 暴雨径流 

分 类 号：X144[环境科学与工程—环境科学]