Author(s): Jiaqi Wen; Haoran Wang; Zhaowei Liu; Yongcan Chen
Keywords: No Keywords
Abstract: The operation of hydropower plants causes a discharge fluctuation that is different from natural flow regime, affecting river benthic macroinvertebrates’drift process, which could be driven by the variation in flow condition. Through a field experiment on Yaojikan stream, Beijing, how Gammarus’drifting process responds to flow fluctuations was studied. Results indicate that when a discharge changes rapidly, the drift density of Gammarus increases remarkably. Gammarus’drift response to flow disturbance is habitat-specific, riffles being the most sensitive and ponds being the least. Average and maximum drift amount under the initial disturbance are both distinctly higher than the subsequent disturbance. There is a remarkable cross effect between disturbance order and discharge towards average and maximum drift density, while a cross effect between discharge and habitat type exists in maximum drift density and ratio of extremes. Shear stress is regarded as an important factor to benthic macroinvertebrates’drifting.