大沽夹河生态健康的生物学评价

Ecological Health Bioassessment Based on Benthic Macroinvertebrate in Dagujia River

通过背景资料调查、野外采样、实验室分析与鉴定,获得大沽夹河流域23个采样点的物理、化学和生物学指标数据.采用全部采样点数据的95th(或5th)百分位标准化指标数据,利用简单加和法计算综合指数,并根据参考点综合指数的25th百分位划分生态健康级别,评价各采样点生态健康.结果表明:底栖大型无脊椎动物是河流生态健康最综合的指示器,但其特征不能准确指示水质现状;利用采样点数据百分位进行指数标准化和生态健康级别划分,可体现评价标准的区域性特征;评价结果显示,大沽夹河生态健康不佳.

By investigation, sampling, analysis and identification, the data of physics, chemical and biological indexes were obtained at 23 sampling sites. The 95^th percentile （or 5^th percentile） data of benthic maeroinvertebrate index value of all sampling sites were used to standardize the index value, simple addition method was used to calculate synthesized index value, and the 25^th percentile of index value of reference site was used to divide the rating of ecological health and assess the ecological health of all sampling sites. The results show that benthic macroinvertebrate is the most synthesized indicator for river ecological health but cannot indicate the water quality actuality accurately. It shows the regional characteristic of assessment criterion to use percentile of index for standardizing index value and dividing ecological health rating. The ecological health of Dagujia River is poor.