Study on the ecological flow process of medium-sized mountainous rivers based on hydraulic habitat protection

Abstract

The proposal of ecological flow is of great scientific significance to conserve river biodiversity. To date, the parameters given by the Eco-hydraulics method are applicable to large rivers. The reference standard is obtained according to the hydraulic habitat parameter standard for fishes in large river and the characteristics of medium-sized mountainous rivers. It can be applied to medium-sized mountainous river and provide better protection for fish. Taking the Zagunao River as the study background, the prototype observation results prove that the reference standard is reasonable. The modified Eco-hydraulics method and the habitat simulation method were coupled to determine the ecological flow process of the Zagunao River. The ecological base flow of the river channel was 17.43 m3/s. The proposed peak and valley values of the ecological flow process was 20.9 m3/s and 17.43 m3/s during the spawning period, respectively. Given the demand of fish for spawning signals, it is suggested to create 1 or 2 ecological floods before the spawning period. The ecological flow process obtained by the method due to considering the survival requirements of Schizothorax prenanti and the hydrological requirements of spawning, can better satisfy the spawning demand of Schizothorax prenanti.