【作者】 赵明；

【导师】 马超； 苏广新；

【作者基本信息】 天津大学 ， 水利工程（专业学位）， 2017， 硕士

【摘要】 三峡水库在提高长江中下游河道的防洪标准、水能水资源利用程度、供水航运条件等方面发挥了巨大作用,但也产生了水环境和水生态方面的不利影响,如库区上游支流水华,长江中下游汛期鱼类繁衍期推迟,鱼卵数量持续下降等。鱼类繁衍与河道水流条件相关,如何优化调整三峡水库在鱼类繁衍期的调度方案,在保障水库既定功能的基础上,改善下游河道鱼类繁衍水流条件,是当前亟待解决的难题。基于此,开展“考虑汛期鱼类繁衍需求的三峡水库多目标优化调度问题研究”。主要研究内容和结论如下:第一,系统总结了长江中下游鱼类繁衍条件的研究成果,根据鱼类繁衍所需水流条件,提出了繁衍期三峡水库的泄流要求,即在6月15日至7月20日间,至少形成一场持续涨水时间不少于5天的涨水过程,且日下泄流量增幅为900~3000 m~3/s,最大下泄流量不超过30000 m~3/s。基于泄流要求,制定了九组鱼类繁衍期三峡水库生态流量方案。第二,开展了繁衍期径流特性分析和基于copula模型的繁衍期径流与繁衍前期径流的关联分析,预判鱼类繁衍期三峡水库的来水量级和概率。分析了繁衍期入库径流对生态流量方案的满足程度,并提出了不满足情况下的提前蓄水方案。结果表明:2004年~2013年,入库径流的满足程度较低,应考虑提前蓄水;根据来流不同,提前蓄水水位范围为145.0m至159.34 m,提前蓄水可能与防洪存在矛盾。第三,综合考虑水量平衡、库容~库水位关系、电站发电能力、水库和电站最大泄流能力、下泄流量~尾水位关系、初末水位等约束,构建了以发电量最大、生态流量满足度最高、超下游河道安全泄量之和最小为目标的鱼类繁衍期三峡水库多目标优化调度模型,并提出遗传算法结合Pareto优选的模型求解思路。第四,选择典型枯水、平水、丰水情境,利用构建的多目标优化调度模型优化提出侧重发电目标、生态目标或防洪目标的三峡水库鱼类繁衍期调度方案,通过对比分析决策条件对调度方案的影响,提出了鱼类繁衍期三峡水库多目标优化调度策略。典型枯水情境下,建议依据繁衍期前期来水特征和繁衍期来水预报信息,制定合理的提前蓄水方案,在不增加三峡水库防洪风险的前提下提高电站发电量和繁衍期径流满足程度。典型平水情境下,可侧重发电目标与生态目标进行调度决策,因来水满足繁衍期需水,无需采取提前蓄水方案。典型丰水情境下,应仅侧重防洪目标进行调度决策,否则将产生防洪风险。更多还原

【Abstract】 The Three Gorges Reservoir has played a great role in improving the downstream flood control standards,the utilization of water resources,the water supply and shipping condition in the middle and lower reaches of the Yangtze River.However,it also has adverse effects on the water environment and water ecology,such as:the water bloom in the upper tributaries,the delay of fish spawning time,and the reduction number of fish larval in the middle and lower reaches of the Yangtze River.Fish reproduction is closely related with the flow conditions.Thus,it is urgent to study how to adjust the reservoir dispatching schemes,which can improve the flow conditions on the basis of maintaining the current reservoir function.Based on this,optimal dispatching strategy of the Three Gorges Reservoir considering fish reproduction in flood season was studied.The main contents and conclusions of the study are as follows:Firstly,the paper systematically summarized the research results of the flow conditions of fish reproduction in the middle and lower reaches of the Yangtze River and proposed the discharge requirements of the Three Gorges Reservoir during the fish reproduction period.According to the flow conditions,the Three Gorges Reservoir should plan at least one flow release with flow rising time no less than 5 days,increasing range of daily discharge from 900 to 3000 m~3/s,maximum discharge flow no more than30000 m~3/s during June 15 to July 20.Based on the discharge requirements,nine groups of ecological discharge plans of the Three Gorges Reservoir during the fish reproduction period were formed.Secondly,through the runoff characteristics and Copula correlation analysis,the inflow amount and possibility were predicted.And then the satisfaction degree of the predicted inflow was calculated according to the ecological regulations during the fish reproduction period.The advance water storage scheme was proposed for the low satisfaction degree situation.The results showed that:it’s necessary to store water in advance due to low satisfaction degree of incoming flow from 2004 to 2013.And the reasonable storage water level is from 145m to 159.34m.Besides,the contradiction between advance water storage and flood prevention risk was analyzed.Thirdly,a multi-objective optimal dispatching model considering fish reproduction of Three Gorges Reservoir was built which aimed at maximum generation capacity,greatest satisfaction of ecological flow process and minimum over-discharge compared with safety discharge of downstream channels.Considered constraints in the model were water balance,relationship of water level and reservoir capacity,generation capacity of power station,maximum discharge of reservoir and power station,relationship of tail water level and water discharge,initial and final reservoir level,etc.The Genetic Algorithm combined with Pareto optimality was used to solve the model.Fourthly,choosing the typical dry,normal and wet inflow situations,the Three Gorges Reservoir dispatching process were simulated by using the model mentioned above.Dispatching schemes were proposed by taking the power generation objective,ecological objective or flood control objective into consideration.Comparing the influence of decisions on the dispatching schemes,the optimal dispatching strategies of the Three Gorges Reservoir with fish reproduction considered were proposed.In the typical dry inflow situation,more reasonable water storage scheme should be made on the basis of the characteristic of the inflow and forecasting information,by which can generate more power and improve the satisfaction of ecological flow.In the typical normal situation there is no need to store water in advance,and dispatching schemes can be decided by power generation objective or ecological objective.In the typical wet inflow situation,flood control objective should be prior adopted to avoid the significant flood risk.更多还原