Abstract: Water temperature is a key ecological factor affecting fish and their habitat, and its changes have a significant impact on fish physiological processes and behavioral patterns. The Tongluowan river section was located in a national nature reserve for rare fishes in the upper reaches of the Yangtze River, and the water temperature was an important factor to be considered in the construction of Minjiang ecological waterway. The hydrodynamic module of MIKE 3 software was used to simulate the three-dimensional water temperature structure of the water body in the Tongluowan section of the lower Minjiang River under the lowest design water level condition. The simulation values of three points were taken and verified by the measured data that the proposed model had relatively high reliability. The research results show that the water temperature stratification characteristics exist in the side beach area on both sides of the water body in the Tongluowan river section, and the water temperature values are higher than those in the channel area which is more favourable to the survival of fish. The water temperature at the deep pits of the side beach is more constant and closer to the suitable water temperature for the main fish in the lower reaches of Minjiang River, and the bottom environment of the water body is more favorable for benthic fish to feed and spawn. It is recommended to minimize the engineering measures such as reef blowing and excavation of the riverbank in the Tongluowan river section to reduce the impact on fish habitat.

Key words: waterway engineering; lower Minjiang River; fish habitat; water temperature simulation; MIKE 3 software

摘要： 水温是影响鱼类及其栖息地的关键生态因子，其变化对鱼类的生理过程和行为方式有着显著影响。铜锣湾河段位于长江上游珍稀鱼类国家级自然保护区内，水温是岷江生态航道建设的重要考虑因素。利用MIKE 3软件的水动力模块，对岷江下游铜锣湾河段区域的水体进行最低设计水位工况下的三维水温结构模拟，取三点的模拟数值利用实测数据验证，模型具有较高可靠性。研究结果表明：铜锣湾河段水体两侧边滩区域存在水温分层特征，水温数值相较航道区域水温更高，对鱼类生存更为有利。边滩深坑处的水体温度更为恒定且水温也更接近岷江下游主要鱼类适宜水温，同时水体底部环境更利于底栖鱼类觅食产卵。建议尽量减少对铜锣湾河段边滩区域的炸礁、开挖等工程措施，以降低对鱼类生境的影响。

关键词: 航道工程；岷江下游；鱼类生境；水温模拟；MIKE 3软件