Integrated Ecosystem Health Assessment of the Niyang River after Human-Induced Disturbance in Tibetan Plateau: A Multicompartment Approach

It is urgent time to take serious consideration of hydro-ecology for the Niyang River, followed by human-induced disturbance, including construction of Duobu Hydropower Station and Lhasa-Nyingchi highway. Four sampling sites along the Niayng River were sampled for water quality indices, water iron related factors, eco-exergy indicators including eco-exergy, structural eco-exergy, ecological buffer capacity, together with aquatic communities, involved phytoplankton, periphytic algea, zooplankton and periphytic protozoa, during dry seasons (March 2009, April 2014), rain seasons (June 2009, July 2013), and moderate climate seasons (September 2009, October 2013) from 2008 to 2014. Generally, total abundance of five aquatic organism communities in downstream were higher than that in upstream. Before the construction of the Duobu Hydropower Station and Lhasa-Nyingchi highway, hydro-ecology of Niyang River mainly displayed relatively medium productive and stable, together with healthy hydro-ecology compared with that of during construction. Meanwhile, obvious differences of water quality indices and water iron related factors were observed following the anthropogenic activities. But no significant difference was observed in eco-exergy indicators and aquatic communities diversity indices before or during anthropogenic activities. Close attention should be paid to hydro-ecosystem health assessment to ensure sustainable development of the plateau river ecosystem.