基于突变级数法的千岛湖流域生态安全评价

针对千岛湖流域生态系统退化、生态安全受到威胁的现状,对千岛湖流域生态安全进行了综合评价,以识别影响流域生态安全的主要因素.研究引入了基于突变理论的多准则评价方法--突变级数法,基于压力 状态 响应(PSR)模型构建了由15个相关指标组成的评价指标体系,对千岛湖流域2008~2011年间的生态安全进行了全面评估.评估结果表明,2008~2011年间,千岛湖流域生态安全2010年达到较安全级别,其他年份均处于基本安全的级别.相对而言,压力系统的安全度最低,状态系统安全度最佳.研究结果表明，虽然目前千岛湖流域生态安全状况较好,但总体状况、压力和响应指标都显示出下降的趋势,说明千岛湖面临着较大的安全压力. 

Ecological security assessment of Qiandao Lake based on catastrophe theory

Qiandao Lake is an important water source and plays a significant role in the local community.However,along with the economic and social development,an increasing amount of pollutants have been discharged into Qiandao Lake and result in ecosystem degradation.So it is necessary to identify the major factors influencing the ecological security of Qiandao Lake through comprehensive assessment.A multiple criteria assessment method based on catastrophe theory was adopted to assess the ecological security in this paper.Based on the pressure-state-response（PSR）framework,the catastrophe assessment index system consisted of 15 related indicators was set to analyze the ecological security of Qiandao Lake during the year of 2008-2011.Results showed that ecological security of Qiandao Lake was moderately secure in 2010,and lightly secure in other years.As for the relative index,the eco-security level of pressure index was worst and security degree for state index was much better.The results also indicate that the ecological security state of Qiandao Lake is good at present,while the index of PSR is descending which indicates that the ecological environment still faces huge security pressure.