Health Assessment and Protection Countermeasures of Ecosystem of the Dajiu Lake in Shennongjia

The Dajiu Lake is an important subtropical alpine wetland in central China.In May of 2019,an ecological investigation was conducted on water quality and aquatic organisms(phytoplankton,zooplankton and zoobenthos)of the Dajiu Lake in Shennongjia forest region.The results showed that parameters of water quality in No.5 and No.9 sub lakes of the Dajiu Lake corresponded with standard of class II water of the Environmental Quality Standards for Surface Water(GB 3838-2002),while other sub lakes corresponded with standard of class III water.Diversity indexes of phytoplankton and zooplankton ranged from 2.0 to 3.0,and there were two families(Chironomidae and Libellulidae Rambur)of one phylum(Arthropoda)in zoobenthos.Comprehensive health index of entropy weight was used to evaluate water ecological status of the Dajiu Lake,and water quality of No.5,No.8 and No.9 sub lakes was in a healthy status,while other sub lakes were in sub-health status.Finally,corresponding countermeasures were proposed according to protection needs of the Dajiu Lake.