Liaohe River Biological Assessment Of River Water Quality

The research is content of seventh special topic-"stratagem research of water,environment management in river basin areas"(number:2003BA614-04-07-03) whichbelongs to one of major research items of our country's tenth five plan-"the gross controltechnology and exemplary of river basin water pollutant ". The task aims at studyinginteractive relationship between river chemical index, aquatic bacteria, benthic animalsand quality of inhabitant area;and also setting up a evaluation standard and index systemfor water ecological system in China's river basins.The task takes Liao River basin in northern part of China as case area where thereare clusters of cities and developed agriculture and industry. However, water is pollutedseriously and water ecological system degenerate greatly in this area.We separately thirtyrepresentative stream sites in Liao River basin.By adopting correlated analysis we make acomprehensive judgement and selection for selected ecological evaluation indexes. Weput forward representative indexes, and set up biological integrity evaluation indexes andstandards for river system of Liao River basin basin.Main research contents:1.Bio-assessment in Liao River basinWe made thirty representative sites in April and June 2005, then we mensurated andanalyzed benthic animals and aquatic bacteria which gathered from Liao River basin. Wealso analyzed communities of benthic animals of Liao River basin. After that, weappraise current water situation of Liao River basin by the index of Shannon-Weaver andnumber of coliform and aquatic bacteria.2.Appraisal by chemical standard in Liao River basinWe analyzed water pollution characters in Liao River basin and researchedinfluenceable principles that water pollution have made on aquatic by measurement andanalysis of benthic animals.3.Quality of aquatic inhabitant area in Liao River basinAccording to Liao River basin's character we put forward ten aspects which canreflected quality of inhabitant: bottom;Roosts complexity;Speed and depth;dikestability;River course change;water volume condition;Vegetation multiplicity;Waterquality condition;intensity of human moving;type of the bank soil using. We researchedthe influence which quality of aquatic inhabitant have made on benthic animalscommunities.4.Evaluating system of B-IBI(benthic index of biotic integrity)in Liao River basinAccording to observing date of fixed quantity and quality analysis toward benthicanimals in April and June, we used basic principle of B-IBI index system to evaluatewater creature integrity. By selection Twenty-one candidate metrics, we set up B-IBIevaluation standard for Liao River basin. At last, we made scientific conclusion onhealthy status of Liao River basin.Main conclusions:1.Benthic animals were gotten in Liao River basin including 4 phylum 7 calss 16order 37 family 93 genus 135 species. Among 135 species, 87.6% belong to aquaticinsect, 8.6% mollusca, 2.0% anthropoda, 0.8% shellfish. The mountain river appearedbenthic animals that lived in clean and light pollution river, while downriver appearedbenthic animals that lived in serious pollution river.With pollution increase, the index ofShannon-Weaver reduced, and the proportions of dominance species rised constantly.2.The result of the chemical monitor index shows that the up water quality isbasically good, while the downriver water is serious polluted.Several items ranged fromone to nine surpassed III standard of the surface water.Mainly pollution is CODcr, NH4-N,oil, BOD5 and the number of E. Coli, etc.The water quality of upriver is better thandownriver.The majority of upriver conforms to III standard.3.According to observing date of fixed quantity and quality analysis toward benthicanimal in April and June, we use basic principle of B-IBI index system to evaluate watercreature integrity. By selecting index of benthic animal to build B-IBI for Liao Riverbasin, we chose total number of taxa, EPT taxa, Chironomidae taxa, three dominanttaxa%, clingers%, intolerant taxa%, as evaluation index of B-IBI. We set up B-IBIevaluation standard for Liao River basin in April and June.The biology integrity of 9 siteswas high in April, and 11 sites in June. In all sites, The B-IBI of Liao He Yuan and HeiYing Tai was zero. The result indicated that quality of aquatic inhabitant affected B-IBIvalue. The more serious pollution was, the lower B-IBI index decreased.4.B-IBI was the comprehensive reflection of chemical index and aquatic inhabitantquality.B-IBI was positive correlation with DO and quality of aquatic inhabitant, negativecorrelation with CODcr,BOD5.