水库对嘉陵江流域鱼类繁殖的影响评估

Evaluation of the Impact of Reservoirs on Fish Reproduction in the Jialing River Basin

摘要: 水库的生态影响评估可为水资源综合管理提供依据。传统统计学方法确定的生态流量难以反映整个河流的满足情况，对目标保护鱼类的分析也缺乏系统性。本文以嘉陵江为例，首先，构建保护物种优先级评价体系，依照珍稀性、受人类影响程度和经济价值进行打分，按照分数排序选出12种代表性鱼类；其次，分析目标鱼类最佳产卵温度，鱼卵漂浮阈值，并按照产粘沉性卵鱼类和产漂流性卵鱼类进行分类；再次，基于水力学模型将流速阈值转化为若干断面的流量阈值；最后，分析嘉陵江水温、流量特征变化，以刺激产卵涨水时间和鱼卵漂浮流量阈值作为指标，评价水库对保护鱼类的影响。结果表明，水库使得鱼类产卵期的平均温度降低，年均最佳涨水天数频次减少。该论文可为嘉陵江流域生态调度提供技术支撑。

Abstract: Ecological impact evaluation of reservoirs can provide a basis for integrated water resources management. Previous ecological evaluation methods lack systematic analysis of target protected fish species, and ecological flows determined by statistical methods are difficult to reflect the satisfaction of the entire river. Taking Jialing River as a case study, this paper establishes a prioritized evaluation system for species conservation. Firstly, an evaluation system for prioritizing protected species was constructed, with scores based on rarity, degree of human impact and economic value, and 12 representative fish species were selected in order of their scores. Subsequently, the optimal spawning temperature and egg buoyancy threshold of the target fish species were analyzed, categorizing them into species that lay adhesive or buoyant eggs. Then, the conversion of flow rate thresholds to flow rate thresholds based on hydrodynamic simulations. Finally, the changes in water temperature and flow characteristics of the Jialing River were analyzed, and the stimulation of spawning rise time and egg floating flow thresholds were used as indicators to evaluate the impacts of reservoir on the protected fish species. The results showed that the reservoir led to a decrease in the average temperature during the fish spawning period and a decrease in the frequency of the annual average optimal number of days of high water. This paper can provide technical support for ecological dispatch in the Jialing River basin.