湿地生态系统健康评价指标体系 Ⅱ.方法与案例

Establishing an Indicator System for Ecosystem Health Evaluation on WetlandsⅡ.An Application

湿地生态系统健康是一个非常复杂的问题 ,不同的湿地类型 ,衡量指标和标准也不尽相同。以三江平原挠力河域湿地作为案例研究 ,分析的湿地主要为闭合流域内的沼泽湿地和河缘湿地 ,以此为基础 ,确定三大类指标 ,即湿地生态特征指标 ,功能整合性指标和社会环境指标。在三大类指标内 ,又分别分出各自的具有可操作性的亚指标。因为健康是一个模糊概念 ,因此 ,根据模糊综合评判原理和方法 ,在对挠力河流域进行湿地分区的基础上 ,对各区的湿地进行了评价与比较排序 。

The ecosystem health evaluation remains a big problem for wetlands,because different assessemnt indicatiors or criterions are required for assessing the corresponding ecosystem health of diversified wetlands.In an attempt to develop a comprehensive approach to evaluate the wetland ecosystem health,it becomes evident that the use of a single indicatior or a method would not give a picture of wetland quality as thorough or holistic as would the application of a suit of differing indicators.The ecosystem health of the wetland of Naolihe River drainage at the Sanjiang Plain is therefore evaluatied in this continued section,as an application of the theoretical framework set up in the previous section of the paper,by employing a system of indicators falling in such three groups as ecological identity indicators,the indicatiors of functional integrity and the indicators associated with socio\|political conditions.These indicators are assigned differing weights respectively to portray the states of ecosystem health of the eight wetland units classified mainly by the first\|order tributaries of the Naolihe River and other aspects including the physiognomy and the topography.Moreover,an integrated assessment model based on fuzzy sets is used in evaluationg and ranking the health states of the eight wetland units,and a signal system of traffic lights is simulated here to extend early warnings to the studied wetlands.In this study,the wetland health is divided into such five grades as extremely healthy,fairly healthy,healthy,morbid and ill.These health grades are denoted by a spectrum of values of an index.Where the value of a heathe index exceeds 0\^65,the evaluated wetland is identified as healthy and denoted by the green lights;where a health index falling in values of 0\^55 to 0\^65,the evaluated wetland is at the critical edge of health and indicated by the yellow lights,and;the evaluated wetland is regarded as ill and marked by red lights,where the value of a healith index goes below 0\^55.Among the eight assessment units,when applying this evaluation system on wetland health to them,only the wetlands of Hamotognghe River and Baoqinghe River can be identified as healthy because the values of their health index exceed 0\^65.While the two wetlands of Neiqixinghe River and Waiqixinghe River are stepping in the critical state of health,the ecosystem heath of the other wetlands has been impaired and shows a worsening trend.Therefore,much more cares should be attached to the impaired wetlands,and further studies on the impaired wetlands may be developed.