Author(s): Jiangyu Dai, Shiqiang Wu, Xiufeng Wu, Dan Chen, Wanyun Xue, Qianqian Yang, Fangfang Wang
Linked Author(s): Jiangyu Dai
Keywords: Water diversion, micro-ecosystem, inflow discharge, quantitative relationship, Lake Taihu.
Abstract: The Water Diversion from Yangtze River to Taihu Lake is a typical eco-hydraulic engineering towards the ecological problems in the large shallow eutrophic Lake Taihu, China. To explore the quantitative relationships among different flow discharges and environmental parameters from the Wangyu River and Lake Taihu, we construct the micro-ecosystems modeling Lake Taihu in the laboratory, with five groups of flow discharges according to the practical discharges of the Wangyu River. Each micro-ecosystem has a volume of 15 L and is studied for a period of 30 days (25 days for the water diversion period and 5 days for the stop period). The results shows that the flow discharges has different extents of impact on the physicochemical and biological characteristics of the micro-ecosystems. The contents of total nitrogen, nitrate, active silicon and bacterial cell abundance in the experimental groups with the flow discharges corresponding to those higher than the 100 m3/s are all decreased comparing to the control group, with the lowest values in the period of 10 to 15 day. After the stop period, the contents of sensitive biotic and abiotic parameters are all recovered with different extents and not to be the initial state of this experiment, which revealed that the effects of the short-term water diversion on lake ecosystems are resilient and durable. There ware quantitative relationships among the flow discharge, content interpolation and variation of water nutrients, with different relationships in different periods of water diversion. The influence of water diversion on lake ecosystems is not only related with the direct impacts of external inputs, but also with the indirect effects of variation in internal lake habitats affected by water diversion
Year: 2017