Study On The Index System Of Lake Ecological Security And Evaluation Methods

Based on summarizing the research development about ecological security and lake ecological security systematically, taking Fuxian Lake and Dian Lake as examples, this paper took study of lake ecological security definition, index system and evaluation methods.This paper systematically combed the definition of ecological security as well as lake ecological security, then it proposed novel views, based on which, it summarized the embodying forms of lake ecological security. After analyzing the PSR concept model and its relative variant models, this study attempted to build an index system of lake ecological security to enrich the thesis of lake ecological threaten. Based on discussing of typical evaluation methods, it originally created index classification evaluation method and assessed the lake ecological security of Fuxian Lake by index analysis method, potential ecological risk index method, BP neural network and GA-BP neural network. At the aspect of lake ecological security recovery, this study took clustering analysis to analyze the 10 typical inflow rivers of Dian Lake, the main results were listed as follows.Lake ecological security was defined as that the lake kept sustainable development under various ecological threats. Its embodying form was the dynamical fluctuation of each index within the range of sustainable development. Based on the theory and model of lake ecological threats, this paper built an index system which included 35 indicators from the terms of eutrophication, lake shrinkage and water pollution. Those 35 indicators were distributed into three classes:macroscopic indexes, heavy metal indexes and comprehensive indexes. Based on which, this paper evaluated ecological security of Fuxian Lake and it got the results that overall ecological security of Fuxian Lake was safe, but some parts still existed threats which needed to strengthen the attention to three indexes including tourism of Fuxian Lake, area source pollution and heavy metal mercury.This paper also made cluster analysis of 10 inflow rivers of Dian Lake, it showed that Hai River, Baoxiang River and Maliao River which were near the center of Kunming were polluted severely and they exerted great threats to Dian Lake. So it was inferred that there existed serious wastewater discharge in Kunming, which needed to strengthen the monitoring and control of the inflow rivers of Dian Lake in order to make it quickly recover.