Aiming at the problem that non-uniform evaluations standards of some biological indices in different basins,a new approach based on fuzzy evaluation was proposed to use the entropy-weighted comprehensive biological index for unifying evaluation standards,and to develop a benthic index of biotic integrity to verify the evaluation results.According to the benthic macroinvertebrates data collected from 10monitoring sites in autumn 2021 and spring 2022,four core parameters including M3(number of Mollusca taxon),M9(relative abundance of pollution-resistant taxa),M13(BI)and M22(Shannon-Wiener)in autumn,and M6(relative abundance of Chironomidae individuals),M13,M16(BPI)and M24(Margalef)in spring were selected from 25 candidate parameters.These core parameters were unified the dimension by ratio method,then summed up to carry out the B-IBI assessment.Besides,this study weighted the BPI,FBI,Shannon-Wiener and BMWP indices objectively to build the CBI,and divided it into five evaluation levels with five equal parts.The results of the two methods showed that the outflowing sites near the river channel were in relatively healthy status.Most of the lake sites are average general and poor,with the health condition in autumn better than that in spring,and the site Liumenzha was in unhealthy status mainly due to low connectivity.After opening the gate near Liumenzha site to release water,the sludge in the sediment may release pollutants,causing the total nitrogen in the lake to exceed the reference standard value,which affected the integrity of the benthic macroinvertebrates.The results of correlation analysis showed that the CBI index and B-IBI,CODMn and TLI(∑)index matched well,indicating that the application of multiple indices would provide a comprehensive evaluation of the aquatic ecological health in the East Dongting Lake.
关键词
大型底栖动物/生物完整性指数/熵权法/水生态健康/东洞庭湖
Key words
benthic macroinvertebrates/integrity of biological index/entropy weight method/water ecological health/the East Dongting Lake
维普
万方数据