【作者】 陈红；

【导师】 王在照；

【作者基本信息】 西北农林科技大学 ， 水生生物学， 2018， 硕士

【摘要】 灞河,古名滋水,是黄河支流渭河的支流,位于陕西省境内。灞河作为“八水绕长安”的八大水系之一,灌溉历史悠久,对西安的工、农业发展具有至关重要的作用。近年来,由于西安工业化和城市化进程的发展,大量未经严格处理的工业废水和生活污水排入灞河,导致其水生态系统遭到破坏。本研究于2016年9月至2017年7月对灞河城市段不同采样点的水环境因子、浮游生物群落结构进行了时空差异分析,并运用Person相关性分析和典范对应分析（CCA）进一步探讨了浮游生物与环境因子的关系,旨在了解灞河的水质状况以及景观河道对水体的净化能力,为城市河流生态系统的保护提供理论依据。研究结果如下:灞河城市段全年各采样点水温变化范围为5.1²9.9℃,季节差异显著;水体pH范围为7.56⁹.75,均大于7,为弱碱性;溶解氧变化范围为4.12¹3.82mg/L,除个别采样点外,全年含量均较高;高锰酸盐指数和总磷的变化范围分别为3.09¹3.52mg/L、0.01⁰.70mg/L,其含量在下游采样点偏高;总氮全年各采样点含量均较高,平均值为10.98mg/L;重金属中除汞含量偏高外,其余含量均较低。根据单因子评价法、综合水质标识指数法以及综合营养状态指数法对研究区域水质进行评价分析,结果表明灞河城市段水体的污染因子主要为TN、TP、COD_Mn和Hg且下游水质状况明显差于上游,特别是污水处理厂出水口处水质最差。灞河城市段共监测出浮游植物7门63属,绿藻门种类数最多,其次为硅藻门和蓝藻门。细胞丰度变化范围为0.73×10⁴⁹8.50×10⁴ind/L,时空分布上整体表现为夏季和秋季明显高于冬季和春季,下游采样点高于上游采样点。优势种共发现7门35属,夏季以绿藻门、蓝藻门为主,冬季以硅藻门为主;主要优势种为小球藻属、颤藻属、小环藻属和隐藻属等,它们主要为中污染、重污染水体的指示种,表明灞河城市段水体已受到一定程度的污染。浮游植物的Shannon-Wiener多样性指数、Pielou均匀度指数和Margalef丰富度指数的变化范围分别为2.14⁴.10、0.45⁰.92和1.04¹.86,根据物种多样性综合评价调查区域水体处于轻污染^中污染状态,且下游污染较严重。典范对应分析和相关性分析表明,灞河城市段浮游植物群落分布主要与WT、TN、pH、DO和Hg有关,浮游植物丰度主要与Chla、COD_Mn、WT、SD、Cd和Pb有关。灞河城市段共监测出浮游动物4类45种,轮虫种类数最多,其次为原生动物、枝角类和桡足类。浮游动物丰度变化范围为20¹084ind/L,时空分布特征与浮游植物基本一致。优势种共发现4类30种,主要优势种为晶囊轮虫、多刺裸腹溞、萼花臂尾轮虫、壶状臂尾轮虫、广布中剑水蚤和钟虫属,它们主要为中污水体的指示种。浮游动物的Shannon-Wiener多样性指数、Pielou均匀度指数和Margalef丰富度指数的变化范围分别为1.08³.25、0.42¹.06和0.70¹.73,根据物种多样性综合评价调查区域水体处于中污染状态。典范对应分析和相关性分析表明,灞河城市段浮游动物群落分布主要与WT、TN、TP、Chla和Hg关,浮游动物丰度主要与Chla、TN、TP、COD_Mn、WT、PH、DO、SD、Hg和Pb有关。综合分析可知,污水处理厂的出水是灞河城市段下游污染加重的一个主要来源,浐河的汇入也带入了一些污染物;景观河道对污染水体具有一定的修复作用,这将为城市水体的修复治理提供了理论依据。典范对应分析和相关性分析表明除常规影响因子外,重金属对浮游生物的生长分布也存在一定的影响,其中Hg对浮游生物群落结构影响较大。更多还原

【Abstract】 Ba river,the ancient name zi water,is a tributary of the wei river tributary of the Yellow River,is located in shan’xi province.As one of the eight major water systems of"eight rivers around chang’an",the Ba river has a long history of irrigation,which plays a vital role in the development of agriculture and agriculture in xi’an.In recent years,due to the development of industrialization and urbanization in xi’an,a large number of without strict treatment of industrial wastewater and sewage into the Ba river,causes the water ecological system is destroyed.In this study,the spatial and temporal difference analysis of water environment factors and plankton community structure of different sampling points in urban section of Ba river from September 2016 to July 2017 was conducted,and the relationship between plankton and environmental factors was further explored by using Person correlation analysis and model corresponding analysis（CCA）.The purpose of this study was to understand the water quality of Ba river and the purification capacity of landscape channel to water body,and to provide theoretical basis for the protection of urban river ecosystem.The results of the study are as follows:Ba river urban section for each sample point temperature change range of 5.1⁵.1℃,the difference was significant in season;The pH range of water is 7.56⁹.75,all of which are more than 7,which is weakly alkaline;The dissolved oxygen range is from 4.12 to 13.82mg/L,which is high in the whole year,except for the individual sample points;The change range of permanganate index and total phosphorus is 3.09¹3.52 mg/L,0.01⁰.70 mg/L respectively,its content is relatively high at the downstream sampling point;The content of total nitrogen was higher in all the year,with an average value of 10.98mg/L;Except that the content of mercury in the heavy metal is relatively high,the balance is low.According to the single factor evaluation method,comprehensive water quality identification index method and comprehensive nutritional status index method to evaluate the water quality in the study area,the results show that the pollution factors of the water in the urban section of Ba river are mainly TN,TP,COD_Mnn and Hg,and the downstream water quality is significantly worse than the upstream,especially the water quality at the outlet of the sewage treatment plant.In the urban section of Ba river,7 phyla,63 genera of phytoplankton were identified,in which the Chlorophyta has the most abundant species,followed by Bacillariophyta and cyanophyta.The variation range of cell abundance was 0.73×10⁴⁹8.50×10⁴ind/L,and the overall expression of spatial and temporal distribution was significantly high in summer and fall,and the downstream sampling point was higher than the upstream sampling point.The dominant species were found 7 phyla 35genera,which were dominated by chlorophyta and cyanophyta in summer and Bacillariophyta in winter;The main dominant species were chlorella,oscillatoria,Cyclotella and Cryptomonas,which mainly indicate the middle and heavy polluted water,show that the water in the urban section of Ba river has been polluted to a certain extent.The variation range of the Shannon diversity index,Pielou evenness index and Margalef abundance index of phytoplankton respectively was 2.14⁴.10,0.45⁰.92and 1.04¹.86,according to the comprehensive evaluation of species diversity,the water body is polluted in light to middle pollution,and the downstream pollution is serious.Canonical correspondence analysis and correlation analysis showed that the phytoplankton community distribution of Ba river urban section mainly related to WT,TN,pH,DO and Hg,phytoplankton abundance mainly related to Chla,COD_Mn,WT,SD,Cd and Pb.In the urban section of Ba river,45 zooplankton species from 4 class were identified,in which the Rotifera has the most abundant species,followed by Protozoa,Cladocera and Copepoda.The variation range of zooplankton abundance was 20¹084ind/L,and the spatial and temporal distribution characteristics were basically consiscent with phytoplankton.The dominant species were found in 4 class of 30 species,the main dominant species were Asplanchna,Monia macrocopa,Brachionus calyciflorus,Brachionus urceus,Mesocyclops leuckarti and Vorticella,and they were mainly the indicators of the middle polluted water.The variation range of the Shannon diversityindex,Pielou evenness index and Margalef abundance index of zooplankton respectively was 1.08³.25,0.42¹.06 and 0.70¹.73,according to the comprehensive evaluation of species diversity,the water body is polluted in middle pollution.Canonical correspondence analysis and correlation analysis showed that the zooplankton community distribution of Ba river urban section mainly related to WT,TN,TP,Chla and Hg,zooplankton abundance mainly related to Chla,TN,TP,COD_Mn,WT,PH,DO,SD,Hg and Pb.The comprehensive analysis shows that the effluent of sewage treatment plant is a major source of pollution aggravation in the downstream of Ba river urban section,and the inflow of the chan river also brings some pollutants;The landscape channel has a certain effect on the polluted water,which will provide the theoretical basis for the restoration and treatment of urban water.The canonical correspondence analysis and correlation analysis show that heavy metal has a certain influence on the growth distribution of plankton in addition to the conventional influencing factors.Among them,Hg has a great influence on the phytoplankton community structure.更多还原