Biological Monitoring Technology Of Water Quality By Using Diatoms In Transboundary Rivers

Recent years, it is of great practical significance to set up reliable biological monitoring programmes to evaluate water quality of Nanning transboundary Rivers in consequence of the water quality deterioration. Especially due to the continuous liquidity of transboundary rivers, pollution is directly related to the vital interests of the people. Attached on the substrates beneath the rivers, diatoms are considered as one of the most suitable organisms in the water quality monitoring and ecological condition assessment because of their high sensitivity to the water temperature,nutrients,organic pollution,heavy metals.Details as follows:1. In this paper, analysis of transboundary rivers’problems in biological monitoring, Across the country for the first time against the background of the crossover section do diatoms biological monitoring research2.232 taxa of epilithic diatoms, belonging to 2 Classes,6 Orders,9 Families and 26 Genera, were identified In the three times of sampling. The dominant species included Achnanthes biasolettiana, Achnanthes minutissima,Aulacoseira granulata,Cocconeisplacetula,Fragilaria capucina,Navicula viridula,Cymbella turgidula and Nitzschia palea,et al.3. This research used a variety of means, such asPCA,DCA,CCA and RDA, to measure various environmental factors on the influence of distribution patterns of epilithic diatom and their relation to water quality.4.Sixteen diatom assessing indices were tested to evaluate the water quality of Nanning transboundary rivers by means of correlation coefficient analysis, factor analysis, cluster analysis, box plot analysis,discriminant analysis and TWINSPAN. EPI-D,IBD,SHE,TID,IPS gave better performance in comparison of the sixteen diatom indices characterized for different water quality groups sorted by physicochemical variables indentified by correlation coefficient analysis and factor analysis. According to five diatom assessing indices,different water quality groups sorted, then to stepwise discriminant analysis of five diatom index, consider the introduction of a combination of different indexes all 31 kinds of classification, combination of IPS and IBD twice a correct classification rate of 100% and 93.8%. Different water quality groups sorted by TWINSPAN means, IBD and IPS showed clear and reasonable trend in the box plots with water quality groups clustered from the diatom communities. We suggested that the IBD and IPS can be applied for monitoring rivers in Nanning transboundary rivers.5. Threee different assessing methods were analysed respectively, they were:Diatom diversity indices,Diatoms assessing indices,Quantitative analysis.6. Based on the analysis of the full text, combining with the research in He Jiang, Bei Jiang, DiaoJiang, liujiang river and hongshui river, to build diatoms biological evaluation of water quality evaluation system with IBD, IPS diatom index, physical and chemical data and Van Dam quantitative analysis, evaluation of river water quality, the data indicate that Nanning transboundary rivers are generally in the middle ranks for water quality.