Habitat suitability models based on different habitat suitability evaluation methods

In addition to being a significant migration barrier, dams and artificial embankments alter their respective habitat's ecological conditions (depth, flow velocity, width and substrate). Moreover, the effects of Dams and artificial embankments are enhanced, causing downstream riverbed erosion, decreasing water quality and loss of habitat for some species. Due to the construction of large dams on the Yangtze River, the spawning sites of the Chinese sturgeon have been obstructed, and the survival of this species is in danger. Habitat suitability simulation model have been developed to analyze, assess, and quantify the impact of dam construction and operation on surrounding habitats and environments. By coupling the habitat suitability function and a two-dimensional mathematical model, a habitat suitability index model for Chinese sturgeon was established. Five methods, including a two-dimensional preference curve method, one-and two-dimensional expert knowledge-based fuzzy logic methods, and one-and two-dimensional data-driven fuzzy logic methods, were used to calculate the habitat suitability of Chinese sturgeon spawning grounds below the Gezhouba Dam. The result show that the data-driven fuzzy logic method is a good method when the amount and coverage (e.g., including very high and very low discharges) of the measured dataset are sufficient. However, conditions at different discharges can be taken into account comprehensively with the expert knowledge-based method when the available data are not sufficient.