典型平原河网地区底栖动物生物指数筛选及评价基准研究

2011年夏、秋季在上海市全境主要河流的83个断面进行大型底栖动物的采样, 共获取底栖动物20个分类单位(种), 其中软体动物、环节动物和节肢动物分别占50%、30% 和20%。选取常见的28个生物指数分别进行计算, 并采用非参数统计检验方法筛选出8个敏感生物指数。通过记分法对8种敏感生物指数统一量纲后, 获得数值范围为8-40的综合生物指数, 运用四分法划分了判别河道水环境质量的生物基准: 32-40, 较好(Good); 24-31, 一般(Fair); 16-23, 污染(Poor); 8-15, 严重污染(Very poor)。9个断面未发现活体生物, 定为超严重污染(Super poor)。依照生物基准比较上海市41个代表性断面近5年主要水质理化指标, 基本反映出水质理化指标的空间差异性, 该综合生物指数及判别基准也可适用于评价平原河网地区的河道水质状况。  

Development of multi-metric index based on benthic macroinvertebrates to assess river ecosystem of a typical plain river network IN China

Bioassessment of benthic macroinvertebrate-based multmietrics is a very effective approach to evaluate quality of river water. Benthic macroinvertebrate assemblages were sampled at 83 sites in Shanghai metropolitan area, a typical dense river network plain. A total of 20 taxa of the benthic macroinvertebrate were collected, including 50% of Mollusca, 30% of Arthropoda and 20% of Annelida. Among 74 sites with living samples, 32 relatively clean sites and 42 polluted sites were separated based on Hilsenhoff biotic index discrminatory criteria. A comprehensive evaluation using 28 widely-used metrics was carried out. Furthermore, 8 metrics were selected as the most sensitive ones based on non-parametric tests (i.e., Mann-Whitney U test and Kolmogorov-Smirnov test). By standard scoring method, eight sensitive metrics were unified and integrated into a multi-metric index on a scale ranging from 8 to 40 for bioassessment at each site. Biocriteria values for benthic macroinvertebrate were proposed by quartation, i.e., 8-15, very poor; 16-23, poor; 24-31, fair; and 32-40, good. water quality of 9 sites with no living sample were marked as very poor. According to the biocriteria, 41 typical sites were divided into 5 groups. The past 5-year historical data of physico-chemical water quality indicators have significant difference among 5 group sites. Consequently, the discrminatory biocriteria are suitable for the assessment of the river water quality of the Shanghai city.