Author(s): Xingmin Wang; Yun Deng; Jia Li; Yong Li; Linglei Zhang; Ganggang Bai

Linked Author(s): Yun DENG

Keywords: Ecological regulation of reservoirs; Adaptive management; The stickiness spawning fishes; Habitat suitability evaluation; Fuzzy evaluation

Abstract: Ecological regulation is an important approach of reservoir adaptive management, but its effective evaluation needs to solve two major difficulties: the response mechanism of fish spawning behavior is not completely clear, and how to establish the feedback regulation relationship of hydrological processes to improve the river environmental state is unknown. In this study, the stickiness spawning fishes in the Chinese National Nature Reserve of Rare and Endemic Fishes in the upper reaches of the Yangtze River (Reserve) are taken as the research object, and based on the long-term series data, this research clarifies the fish spawning habitat requirements, constructs the suitability evaluation model based on the fuzzy logic method, reveals the spatiotemporal characteristics under power station regulation, and proposes suggestions for sustainable adaptive management. The water temperature (WT) and daily rising rate of the water level are selected as the evaluation index, and the weights are 0.53 and 0.47 respectively. The spatiotemporal characteristics of habitat suitability are jointly affected by reservoir regulation and tributaries. The specific manifestation is that the discharge of low-temperature water from the reservoir has significantly reduced the habitat suitability of various river sections in March after impoundment. The decrease in the suitability of the Yibin (YB) is most affected by the impoundment regulation reservoir, while the Luzhou (LZ) is affected by the inflow of the tributary Minjiang (MJ) River, which reduces the suitability difference before and after impoundment, and the Jiangjin (JJ) is less affected by the regulation of the reservoir. It is suggested that the ecological regulation plan is: the early April will be designated as the "ecological regulating window period", the outbound flow will be 2000m3/s to 3000m3/s, and the daily average rising rate of flow should be controlled within 200m3/s/d.

DOI: https://doi.org/10.3850/978-90-833476-1-5_iahr40wc-p0841-cd

Year: 2023