Author(s): Zhaoyin Wang; Joseph H.W. Lee; Mengzhen Xu
Keywords: Benthic macro-invertebrate; eco-hydraulics; eco-sedimentation; ecological restoration; golden mussel; habitat; hyporheic zone
Abstract: This paper reviews the state-of-the-art eco-hydraulic and eco-sedimentation studies in China, particularly focusing on the impact of hydropeaking, habitat suitability modelling, bio-invasion control strategies, sediment transport effects on river ecology, and ecological restoration. Field investigations found that macro-invertebrate species number reduced nearly to zero in a short reach downstream of a dam due to hydropeaking, resulting from a hydropower station. Habitat suitability modelling for the Chinese sturgeon indicated that the habitat suitability was reduced after the Three Gorges Dam began filling. Macro-invertebrate species number and fishery harvest reduced sharply after riparian lakes were cut-off from the Yangtze River. Invasion and dense attachment of mussels on water transfer tunnel walls have caused biofouling in many countries. An effective control strategy, using hydraulic control methods for the golden mussel invasion is proposed. Erosion, sediment transportation, and deposition create and change habitats for many macro-invertebrate species. The biodiversity and number density of individual invertebrates are high in stable streams, lower in incised streams and streams experiencing sedimentation, and lowest in streams with intensive sediment transport. In stable streams, macro-invertebrates colonized a layer of bed sediment up to 60 cm, in which different species preferred different depths. For incised streams, the ecosystem was restored with artificial step-pools, which stabilized the channel bed and created high-habitat diversity. The problems and studies presented in this paper indicate the growth points of the discipline of eco-hydraulics and eco-sedimentation.