Study On Reference Conditions Of River Health By Reference Point Method Of Macroinvertebrate

Reference condition as standard of river healthy, is increasingly used todescribe the standard or benchmark against which current condition iscompared in river health assessment. Selecting the Taizi River as subiect, thepaper discuss and formulate reference conditions of river health assessment.First, Based on the long-term sampling of macroinvertebrate communities inTaizi River Basin, By the starting of functional feeding groups analysis, theland-use types that impact macroinvertebrate most in basin-wide werescreened out and sensitive biological indicators of anthropogenic interferencewere screened out. Second, as farmland had been determined impactingmacroinvertebrate most, by specific studied of farmland on themacroinvertebrate and found the water quality factors that closely related tomacroinvertebrate. Scope of the study was narrowed, and selecting South andNorth tributaries as the study area, which has similar habitats, locationproximity, similar climate, but density of farmland quite different. Byordination analysis of NMS and CCA, different intensity of agricultural development impacting a lot to total abundance, the relative abundance ofPlecoptera, and the relative abundance of EPT(Ephemeroptera Plecoptera andTrichoptera) of macroinvertebrate. At the same time, Total Nitrogen(TN),Electric Conductivity(EC), pH were selected to be the water quality factorsthat affected a larger by agriculture and impact macroinvertebrate much.Thirdly, reference points were setted from the river that away from farmland,and the scope of the hydration factors and biological factors were ordained,which constitute the range of reference conditions. The study providingreference for determining reference condition of river health assessment inTaizi River, could promotion to China’s northern rivers according to localconditions.