Development of Biotic Index Based on Macroinvertebrates to Assess the River's Health in Lijiang
The Lijiang River is one of the 15 most beautiful rivers in the world,with high aquatic biodiversity.However,the water quality has been affected due to the rapid economic development.This study aims to develop a biotic index based on macroinvertebrates and to evaluate the ecological health status of the Lijiang River.Based on the identification of macroinvertebrates and water physicochemical data from 26 monitoring sites in Guilin from August,November 2021 to August 2022,a complete set of water quality evaluation index was constructed to scientifically evaluate the water quality of Lijiang River.The Lijiang Zoobenthic Biotic Index(LJBI)proposed in this study analyzed the physicochemical values of water quality at monitoring points using the principal component analysis method and was associated with the distribution of macroinvertebrates.The LJBI values were divided into four level by 25％,50％,and 75％quantiles,representing the health,sub-health,average and poor,respectively.This index divided the Lijiang River water quality health into four levels:excellent,good,medium,and general.The result showed that most of the macroinvertebrates distributed in the Lijiang River were moderately pollution-tolerant species,while the species adapted to clean water quality,such as Nebrioporus spp.,Microvelia spp.,and Aciagrion spp.were only distributed in the upstream.Therefore,it was important to protect the upstream and tributary streams.Based on the classification level of the genus,certain sensitive values were assigned to each genus,and the health status of water quality in the Lijiang River was assessed according to the average value of sensitive values at each monitoring point.The results showed that the water quality in the upper reaches of the Lijiang River was good,for example Qingshitan,Gaozai,and Huajiang sample sites were evaluated as excellent,but the water quality in the lower reaches of the Lijiang River was badly affected by human activities,such as the water body of Jingpingshan sample site was cloudy due to the influence of bridge construction,and the water ecology of this site was evaluated as general by LJBI.The benefits of LJBI contain:(1)It remains unaffected by the quantity of individual species;(2)For the users,is is simple in operation,convenience in calculation,and quick in conclusions;(3)It is convenient to promote the popularization of scientific knowledge of ecological health status of water quality within the Lijiang River basin.
water quality assessmentmacroinvertebrateLijiang Riverbiotic index
国家科技期刊平台
NSTL
万方数据
