Abstract: From July 26 to August 13, 2017, by the methods of on thespot investigation, plot survey, and the analysis of river water and soil samples, we assessed the impacts of construction time, site area of hydropower stations, and hydropower development on water quality, soil and ecological flow in Zhangye section of Qilian Mountains Nature Reserve. The results showed that the construction of hydropower stations was mainly concentrated from 2000 to 2008. The total area for 26 hydropower stations was 798.35 hm², accounting for 0.042% of total area in study region (1.88 million hm²), which indicated that hydropower projects covered a small area. The vegetation coverage and biomass in the construction areas of the hydropower stations were 27.14% and 236.8 g·m^-2 lower than those of the original vegetation, respectively. The water quality and soil of the areas around hydropower stations were in good conditions, indicating that the water and soil were seldom affected by hydropower development. The hydropower development had led to the decrease of ecological water quantity, causing a waterreduction river section with a length of 156.76 km.

Key words: Laizhou Bay, artificial reef, macrobenthos.