南水北调东线工程实施中调蓄湖泊蓝藻种群的响应机制

The South-to-North Water Diversion Project of China is the strategic measure relieving water shortages fundamentally in north China, while the water quality in long-distance water diversion is the key factor to determine the smooth implementation of the project. It is necessary to confirm the possibility of the occurrence of water bloom in the implementation process of the project. Study of phytoplankton community and spatial distribution can improve water quality and avoid the occurrence of water bloom effectively due to the sensitivity of the phytoplankton to water environmental changes. This project intend to conduct a long-term follow-up study during the implementation process, focusing on the water quality, phytoplankton community distribution of regulating lakes in east route of the South-to-North Water Diversion Project. The environmental factors which affect the cyanobacteria population distribution will be determined and the response mechanism to water environmental changes will also be clarified accordingly with the survey and experimental study concerning local hydrometeorology conditions and cyanobacteria growth requirements. Meanwhile, the ability, conditions and rules in water bloom formation of the typical cyanobacteria will be discussed in each regulating lake, which provides advices for aquatic environment protection and prevention for water bloom. In addition, the comparison study for the changes of phytoplankton population distribution during the implementation process of the project may provide theoretical basis for the evaluation of the influence to aquatic environment brought by the implementation of the South-to-North Water Diversion Project.

南水北调东线工程对于缓解我国北方地区水资源短缺、实现水资源的合理配置具有深远的意义，其中调水水质问题是南水北调东线工程能否顺利运行和发挥作用的关键。在工程实施过程中，各调蓄湖泊发生蓝藻水华的可能性是迫切需要明确的问题。湖泊中浮游藻类对环境变化非常敏感，掌握浮游藻类的种群分布特征和演替规律，可以更好地改善水质和预防蓝藻水华发生。本课题在南水北调东线工程实施期间，对各调蓄湖泊的水质状况、蓝藻等浮游藻类的种群分布特征进行长期跟踪研究，明确各调蓄湖泊影响蓝藻种群分布的环境因子，结合湖泊水动力学特征、气象条件和蓝藻的相关实验室研究，阐明蓝藻种群对水环境改变的响应机制，并研究各湖泊蓝藻形成水华的能力、条件和规律，为各湖泊的水环境保护及蓝藻水华预防措施提供理论依据和科技支撑。另外，对南水北调东线各湖泊浮游藻类种群特征在通水前后变化的研究，也可为正确评价工程的实施对湖泊水生态环境的影响提供理论依据。

蓝藻水华不仅危害水体自身的生态结构和功能，更为严重的是蓝藻产生的大量藻毒素，具有较高的致癌性，威胁人们的饮水健康。项目执行期间，受资助人全面覆盖东线工程 4 个调蓄湖泊，系统开展了包含调水前后在内的长时间序列多点位藻类生态学、生理学以及毒理学特征研究，阐明了蓝藻种群的分布特征和演替规律；运用冗余分析等研究手段揭示了南水北调东线工程实施过程中影响各调蓄湖泊蓝藻种群的环境因子; 结合营养盐、水文气象等环境因子，揭示了各调蓄湖泊蓝藻形成水华的条件和规律，阐明了南水北调东线工程实施中调蓄湖泊蓝藻种群的响应机制，建立了从水华主体-产毒蓝藻丰度的时空变化特征入手，结合湖库水文特征辨析水华发生可能性的方法，建立了“种群干扰”抑制产毒蓝藻异常增殖以及蓝藻细胞无破损去除的“湖库-饮用水厂”两级水华预防和控制理论及系列技术。成果发展了蓝藻水华生态学判据，填补了在蓝藻异常增殖初期通过对藻类种群进行干扰来避免蓝藻水华的理论和技术空白，为水质较为稳定的浅水型湖泊水华预测及防控提供了新的思路，丰富了藻类生理学和藻类毒理学理论体系。.此外，受资助人将研究发现与工程实际密切结合，建立了各湖泊分区、分点位，包含物种构成、均匀度、优势种等藻类生态学信息在内的动态变化数据库。为国务院南水北调工程建设委员会提供关于蓝藻水华的咨询报告 4 份。将藻类信息实时反馈工程运行调度部门，实现科学研究和工程指导的有机结合，规避了工程运行过程中蓝藻水华的风险。成果被多家单位应用，效益显著。.受资助期间，受资助人以第一作者（或通讯作者）在Environmental Science & Technology、Water Research、Science of the Total Environment、Environmental Pollution等发表SCI收录论文13篇，其中JCR一区5篇，二区2篇，平均影响因子4.303，总引35次；在生态学杂志、环境科学研究上发表中文论文5篇（均为EI收录）；培养博士5名（与国外联合培养2名），硕士8名；在国际会议作报告2次。