Abstract:The construction of water conservancy projects impairs river connectivity,threatening aquatic organisms.Fishways are crucial for restoring river ecological connectivity,mainly divided into engineering fishways and nature-like fishways.This paper compares the basic types of the two fishways,revealing their apparent differences in construction materials,structural characteristics,environmental adaptability,flow patterns,and fish-passing effects.According to the domestic and foreign case data,this paper quantitatively analyzes differences in key design parameters（slope,elevation height,water depth,width,width-depth ratio,velocity).On the basis of the Itaipu Hydropower Station case,this paper summarizes the range of key parameters for nature-like fishways.The results show that nature-like fishways,using natural materials with rough structures and diverse flows,are suitable for multi-species fish migration,with slope gentler than 120,elevation height mostly below 10m,width-depth ratio over 4,and shallow water depth（mostly less than 1 m).Engineering fishways,made of reinforced concrete with regular structures,are suitable for specific fish,with slope mostly steeper than 120,elevation height of 10-60 m,and width-depth ratio less than 2.
