三峡水库调度对典型支流库湾水华的影响规律及机制研究

The eutrophication and algal blooms in the bays of the Three Gorges Reservoir (TGR) has become the main water environmental problem and is now attracting more and more worldwide attention. Ecological regulation of a reservoir has been accepted by more and more scholars as an effective measure to control the eutrophication and algal blooms in the bays, which is possibly the most effective measure to alleviate the water environmental problems such as algal blooms in the bays of TGR recently. However, the influencing rules and mechanism of reservoir regulation on the algal blooms are still unclear. Therefore, the detailed parameters and programs of the ecological regulation are unable to be presented currently. In this study, operation processes of TGR in a year will be divided into some certain periods according to the yearly water level variation rule and the algal blooms regime, and daily water level changing processes will be classified, then the characterization parameters of the scheduling process will be refined, and various scheduling functions responding to a variety of daily water level changing processes will be established. Taking a typical tributary Bay of TGR as the subject, the influencing rules of different scheduling functions on the algal blooms in the Bays will be analyzed by field monitoring, numerical simulation and theoretical analysis, and ecological regulation types haveing or not sensitive effects on the algal blooms will be distinguished; then the differences of ecological conditions appearing in the bays responding to the different scheduling functions will be compared to reveal the influencing mechanism of the ecological regulation of TGR on the algal blooms in the bays. It is hoped to deepen the understanding of the mechanism of the algal blooms in the bays of TGR, and to provide a theoretical basis for formulating the eco-scheduling programs to prevent and control the algal blooms, and it also has an important theoretical and practical significance for the sustainable development of hydropower in our country.

三峡水库支流库湾富营养化和水华已成为当前三峡库区备受关注的生态环境问题之一，通过水库生态调度调控支流库湾富营养化及水华已被越来越多学者所接受，最有可能成为近期缓解三峡水库支流库湾水华等水环境问题的有力措施。然而，当前水库调度对水华的影响规律及机制尚不清楚，因此无法提出生态调度的详细参数及调控方案。本研究依据三峡水库水位年变化规律及水华暴发情势进行水库调度分期，分析水位日变化过程并进行分类，提炼调度过程的表征参数，建立能反应各种水位日变化过程的调度函数；以典型支流库湾为研究对象，通过野外监测、数值模拟及理论分析等方法分析不同调度函数对水华的影响规律，从中识别对水华有无灵敏影响的调度类型；对比分析不同的调度函数产生的各种生态条件的差异，探明水库生态调度对水华生消影响的作用机制。本研究可进一步深化对三峡水库支流库湾水华生消机理的认识，为防控支流库湾水华的三峡水库生态调度方案的制定提供理论基础。

本课题以三峡水库典型支流水华为研究对象，通过野外监测、数值模拟，研究了三峡水库调度对支流库湾水华的影响规律及机制。基于小波方法分析了三峡水库水位变动特性，计算了不同水位运行期水库生态调度空间，提出“潮汐式”调度方法并系统分析了三峡水库不同调度方法对香溪河库湾水流特性、水温特性、不同分层异重流下水华的影响规律，其中单纯泄水调度对支流库湾影响有限，蓄泄结合，即“潮汐式”调度效果更明显。明确了三峡水库调度主要通过改变干流倒灌异重流方式、增大表层流速、打破水温分层等影响水华的机制，同时结合临界层理论和中度扰动理论进一步揭示了三峡水库调度影响支流水华的影响机理。本研究深化了三峡水库支流库湾水华生消机理的认识，为防控支流库湾水华的三峡水库生态调度方案的制定提供了理论基础。通过项目研究，出版专著1 部，发表了相关论文34篇，其中SCI 4篇，英文核心1篇，会议论文4篇，中文核心24篇，授权实用新型专利5项，获湖北省科技进步一等奖1项，培养了青年学术骨干1名，硕士研究生5名，其中省级优秀硕士论文1篇。举办三峡水库生态环境研究国际研讨会1次，参加国际国内学术交流会10余次。