减水河道水量变化的鱼类饵料生物量响应关系研究

During the development of hydropower, the protection of rare and endemic fishes and the stability of aquatic ecosystem have aroused the concern of people from all walks of life. Scientific configuration can meet the basic water requirement for the survival of fishes and food organism. Maintaining the integrity of the food chain is the key in fish protection. By analyzing literatures, it is found out that the amount of fish food organisms is greatly affected by the changes of river flow, and their quantitative relation is lack of system research. Firstly, the endemic fish schizothorax prenanti and other 1-2 kinds of undetermined fishes in Minjiang River and Yalong River will be selected as the indicator organisms of water ecology. Through field sampling, the live foods of schizothorax prenanti will be investigated and rechecked. Secondly, the structure of suitable physical habitat of food organism will be studied from three dimensions of water quality, water dynamics and sediment structure. Thirdly, single factor affecting indoor experiment will be designed, and by means of environmental hydraulics, the quantitative relationship between the amount of food organisms, hydrodynamic conditions and the concentration of nutrients will be studied. Finally, on the basis of prototype observation and field experiment and numerical simulation, the quantitative relationship model between the amount of food organisms and flow rate variation will be coupled and established. The research results can enrich the ecological information of schizothorax prenanti, and provide technical support and basis for the engineering design of micro habitat restoration of river course, the establishment of ecological constraints, the ecological impact assessment of hydropower construction project and the management of water environment in a river basin.

在水电开发条件下，对珍稀特有鱼类的保护、维持水生生态系统的稳定已引起各界的关注。科学配置能满足鱼类及其饵料生物生存的基本水量，维持食物链的完整是实现鱼类保护的关键。文献分析发现，鱼类饵料生物量受河道流量变化的影响较大，二者间的定量关系尚缺乏系统研究。本申请拟选择岷江、雅砻江的特有鱼类齐口裂腹鱼及另外1~2种待定鱼类作为水生态的指示生物，通过现场采样，对齐口裂腹鱼的生物饵料进行调查与复核；从水质、水动力学、底质结构等三个维度着手，研究饵料生物的适宜物理栖息地结构；设计单因子影响的室内实验，以环境水力学为手段，研究饵料生物量与水动力学条件及营养物质浓度间的定量关系；在原型观测和野外实验的基础上，辅以数值模拟，耦合建立饵料生物量与流量变化的定量关系模型。研究成果可丰富齐口裂腹鱼的生态资料，并为河道微生境修复的工程设计、生态约束的建立、水电建设项目生态影响评价、流域水环境管理提供技术支撑和依据。

鉴于水电开发条件下的河道流量变化与天然径流量变化有着明显的区别，且这种变化受电站运行所控制，会使水文信号失真，并且在库区及闸坝下游形成减(脱)水河段，与天然河流相比，物理栖息地结构将出现严重背离。本申请选择岷江上游的特有鱼类齐口裂腹鱼(Schizothorax prenanti)作为水生态环境质量的指示生物，通过对齐口裂腹鱼生物饵料的研究，以环境水力学理论与方法为主要手段，结合生物学、生态学的理论与方法分析河道流量变化中所隐含的水文信号变化、物理栖息地结构变化的信息，探讨减水河道水量变化的鱼类饵料生物量响应的定量关系这一关键问题，建立水电开发条件下，饵料生物量对河道流量变化的响应的定量评估模型。