Abstract: This study examines the impact of hydropower development on river habitat connectivity, and develops a connectivity optimization path coupling connectivity and benefits, through a case study of the Dadu River basin. We create a database for the 135 hydropower stations in the basin through data collection and remote sensing image identification, and quantify river habitat connectivity using the River Connectivity Index (RCI). The results show that 1) the RCI of this basin is 16.68 at present and will decrease to 4.2 when all the planned power stations are completed in the future, and that the spatial distribution of RCI shows a decreasing trend from upstream to downstream. 2) Hydropower stations located in the middle of the river network have a greater impact than those located in its headwater region or near its tributary. 3) The impact of different hydropower development plans on the connectivity varies significantly, and the connectivity can be improved effectively through reasonable planning while ensuring the development benefits. This study would help river habitat connectivity restoration and watershed strategic planning.

Key words: river connectivity index, habitat connectivity, river fragmentation, connectivity restoration