Abstract:The Ecosystem Health Index (EHI) and Trophic State Index (TSI) were used to assess the ecosystem health and eutrophic status of Erhai Lake and three small lakes (Haixihai, Cibihu and Xihu) in Erhai watershed. According to the field survey carried out in May 2009, all lakes in Erhai watershed were in an eutrophic status (averaged TSI =53.9) and in a worse ecosystems health status (averaged EHI =38.3). Further analysis found that the EHI has a high spatial variability among and between the lakes in Erhai watershed. Haixihai lake (EHI=42.7) and Cibihu lake (EHI = 42.1) had a median score of EHI; however, Xihu lake (EHI=33.5) and Erhai lake (EHI=37.9) had a lower score of EHI. Among Erhai lake, the north and central region had a higher score of EHI than the other regions. A comparison between EHI and TSI in assessing lake ecosystem’s status revealed that lakes in Erhai watershed belong to the response ecosystem that basically shows a positive correlation between nutrient and biomass, and the EHI is a good index in assessing ecosystem health of lakes in Erhai watershed. In addition, the EHI was used to assess the ecosystem health of Erhai lake in the past 20 years. The result indicated that ecosystem health of Erhai lake is degrading. The worst ecosystem state was observed in 1997, with a EHI value of 36.7.
张红叶, 蔡庆华, 唐涛, 汪兴中, 杨顺益, 孔令惠. 洱海流域湖泊生态系统健康综合评价与比较[J]. 中国环境科学, 2012, 32(4): 715-720.
ZHANG Hong-Ye, CAI Qing-Hua, TANG Tao, WANG Xing-Zhong, YANG Shun-Yi, KONG Ling-Hui. Comprehensive assessment and comparison of lakes’ ecosystem health in Erhai watershed. CHINA ENVIRONMENTAL SCIENCECE, 2012, 32(4): 715-720.