Author(s): Ruonan Li; Qiuwen Chen; Duan Chen
Linked Author(s): Qiuwen Chen, Duan Chen, Ruonan Li
Keywords: Fish habitat; Integrated habitat model; Habitat assessment; Cumulative effect
Abstract: Hydropower development alters the natural hydrological regime of the river, thus imposes significant impact to the aquatic ecosystem. The long-term reservoir operations lead to profound influence on fish habitat downstream and hence the biomass and population size. Therefore, recognizing the cumulative effect on fish habitat caused by flow regime variation has fixed more attention, which was studied in this paper using Lijiang River as an example, and the result could be used to conduct the eco-friendly operation and fish habitat conservation and restoration. Spinibarbus hollandi Oshima were selected as the study case to illustrate the method. Firstly, the responses between S. hollandi Oshima and water environment factors, such as water depth, velocity, dissolved oxygen and water temperature, were set up through field investigation and fish behaviour experiments. Moreover, fish habitat model, which based on fuzzy logic and genetic algorithm, integrated with two-dimensional water quality model. Finally, the relations between flow and habitat quantity factors, and between flow and habitat quality factors, like habitat suitability and habitat fragment, were discovered. By these relations, the tendency for years on the S. hollandi Oshima habitat, which caused by flow regime variation upstream, was discussed from both quantity and quality aspects and the cumulative effect on fish habitat would be revealed. The results showed that the flow regime change has positive effect on the fish habitat. It is seen from the study that integrated habitat models are a useful tool to assess river ecosystem and support river restoration.