Author(s): Li Dang; Jijian Lian; Chao Ma
Keywords: Ecological river; Fish habitat; Habitat suitability model; Habitat suitability index (HSI); Weighted usable area (WUA)
Abstract: The river bank-line planning taking flood control as the main purpose generally influences aquatic habitats in different extent. It is necessary to evaluate the quality of habitats quantitatively, in order to maintain and enhance the ecological structure and function of the channel better. Habitat suitability models, based on different requirements of different aquatic species, have been widely used to research the pressure-impact relationship between aquatic life and their habitats. Taking six fish species typical of Chinese channel (including the four major Chinese carps, carp and crucian) as the target objects, a habitat suitability model in consideration of all life stages (including migration, spawning, egg stage, juvenile stage and adult stage) is developed in this paper. The model is integrated with a 2D hydrodynamic model with habitat suitability index (HSI) and weighted usable area (WUA) as core assessment indices. The water depth and velocity which are calculated from the hydrodynamic model are used as the input of the habitat suitability model to assess the river habitat quality. Taking Wanquan River as an example, three bank-line schemes have been proposed for flood control upon previous studies, in which the habitat quality was not considered. Then, the habitat suitability model is applied on it to assess the habitat quality of the original channel and the three schemes. The results show that the variation of habitat quality in different scenarios could be reflected clearly in the habitat suitability model. And compared with the original channel, the habitat conditions of the three bank-line schemes change slightly, which indicates that all these schemes could be adopted in consideration of habitat suitability only.