An Assessment Of Ecosystem Health For Shallow Lakes In Wuhan

Health and relative stability of ecosystem are necessary to human survival and development .It is very important to maintain ecosystem health and its well-circulation. In the last 10 years, the concept of ecosystem health was brought forward and has become the new focus and most active front in ecology studies. Abroad, ecosystem health studies on agro-ecosystem , forest ecosystem and urban ecosystem, et al. In recent years ecosystem health has also got more attention at home, but study on lake ecosystem is still out of sight.According to summary of the concepts for general ecosystem health and analyzing the characteristics of lake ecosystem, a healthy ecosystem can be seen from two aspects: On the one hand, this natural-ecosystem-social compound ecosystem should be stable, sustainable, and resistant to outside stresses ecologically. On the other hand, lake ecosystem should, from social-economy point of view, have the ability to provide citizens sustainable ecosystem services. Healthy ecosystem is characterized as vitality, vigor, structure with biodiversity and equilibrium and should function with efficiency.There is no generally acknowledged method to assess ecosystem health, especially for lake ecosystem health. Based on lake ecosystem assessment theory, using the general ecosystem health standard given by Costanza for reference, the author build an initial indicator system for lake ecosystem health assessment, and filter those indicators with redundancy information. Then the final index system formed. By using the fuzzy mathematics method, the model of lake ecosystem health assessment is created. Finally the approach for assessing lake ecosystem health, including index system, index weight, assessment standard and assessment model, is brought forward.The method, principal component analysis, was successfully applied to the assessment and comparison of ecosystem health for Wuhan lakes. It can be widely used for the quantitative assessment and comparison of ecosystem health states for single and different lakes.