B-IBI在东江河流健康评估中的应用研究

基于东江流域24个采样点的底栖无脊椎动物监测数据，构建生物完整性指数，采用比值法统一筛选出的核心参数的量纲，将各个参数累加得到B-IBI值.以参照点B-IBI值的25%分位数为健康基准值，小于25%分位数值的进行4等分，划分河流生态健康评价标准：B-IBI387为健康；290B-IBI387为亚健康；193B-IBI290为一般；097B-IBI193为差；B-IBI097为极差.运用构建的B-IBI对东江流域的主要干支流进行健康评估，结果显示，全流域24个样点中达到健康和亚健康水平的占292%，一般占292%，差和极差占416%.

Application of Benthic Index of Biotic Integrity (B-IBI) to Assess the River Ecosystem Health in Dongjiang Watershed

Based on the monitoring data collected of benthic invertebrate from the 24 sampling sites, a preliminary Benthic Index of Biotic Integrity (B-IBI) was developed to assess the health status of main stream and tributaries in Dongjiang Watershed. Totally 30 candidate metrics which related to benthic's community structure and function, feeding function, interference tolerance and habitat were evaluated by distributing range analysis, sensitivity analysis and Pearson correlation analysis. The final B-IBI included total taxa number, EPT taxa number, relative abundance of EPT taxa, three most-dominant taxa, scrapers and gathers. The dimension of the core metrics were unified by rationing and the scoring normalized based on the quadrisection system, and these scores were interpreted as health (387), sub-health (290-387), normal (193-290), poor (097-193) and very poor (097). The results showed that in the whole Dongjiang Watershed 292% of sampling sites were in health and sub-health conditions, 292% of sampling sites were in normal conditions, and 416% of sampling sites were in poor or very poor conditions.