Evaluation Of Water Quality Based On Planktonic Algae In Guanlan River

China’s rivers, especially the rivers in the developed urban cities, the pollution situation isvery serious, which has seriously affected the quality of citizen’s life and caused widespreadconcern and attention. As a functional group, planktonic algae can indicate the class of waterpollution accurately, sensitively and long-period effected, which has widely used in the evaluationof water pollution.The experiments were practiced in the dry season and abundant period along the GuanlanRiver. According to the natural conditions, the pollution situation, tributary joining conditions andrestoration of the Guanlan River, we divided the whole reach into six monitoring sections （E1toE6） to investigate the physical and chemical factors of water quality, hydrological factors, as wellas the species and amount of planktonic algae. We also evaluate Guanlan River water qualitythrough the indicator species for water quality physical and chemical factors and planktonic algae,biodiversity index, algae nutrition index. The results are summarized as follows（1）Through physical and chemical indicators, the average data of investigation in the dry seasonof Guanlan River reaches as follows:17.92mg/L（BOD₅）,59.52mg/L （CODcr）,18.47mg/L（N/NH4）,20.90mg/L（TN）,1.69mg/L （TP）,7.13（pH）. Through physical and chemicalindicators, the average data of investigation in the abundant season of Guanlan River reaches asfollows:12.16mg/L （BOD₅）,40.03mg/L （CODcr）,8.4mg/L （NH4-N）,13.81mg/L （TN）,1.41mg/L （TP）7.36（pH）. According to the standards and restrictions of the basic project of thenational surface water quality environmental standards, we get that the water quality of the GuanlanRiver is Ⅴ class in the dry season and wet period. During the dry season and wet period, in additionto the small changes of pH between each section, other indicators are formed U-shaped graphicshapes from E1to E6. The pollution of E1and E6is relatively serious, the pollution of E4and E5more serious, and in E2, E3pollution is relatively lightest. Water physical and chemical indicatorsfor monitoring results show that: through the ecological management of river （E3）, water quality isbetter than traditional methods of governance and governance of Water Quality.（2） The Guanlan river in dry season we identified four18genera of the phytoplankton. In additionto the E1cross section identified as bare bloom, and the rest of the section diatoms on the amount,type, population density, dominant species are dominant. five31genera is identified in theabundant period among them, diatoms are dominant in kind, quantity, population density and thedominant species. The population density and the number of species of cyanobacteria increased inthe wet period than the dry season.（3） the biological evaluation of water quality through indicators as follows: there are10kinds ofpollution indicator species in the dry season of the Guanlan river, i.e. one kind of α-Multiple indexwith （Euglenophyta）; hree kinds of β-Multiple index （a boat-type algae, seats algae, direct chain of algae）; two kinds of α-Multiple index （Scenedesmus, Oscillatoria algae）; two kinds ofbeta-dirt with （needle bar algae, Nitzschia）; one kind of few dirt （Cyclotella）. More than dirtwith four kinds of indicator species in the dirt with three kinds, one kind of few dirt, show that thethe Guanlan river as a whole in a multi-pollution belt. Guanlan River of the wet period, a total of16kinds in the dirt with nine kinds, the Guanlan river wet period in the dirt with.（4） Biodiversity index of water quality evaluation results: in the dry season, river courses andthe diversity index of each section an average of1.67, classified as moderately polluted, includingthe E1cross section for the most polluted, heavily polluting; E2and E4minimum degree ofpollution, light pollution; the rest of the section are moderately polluted. The diversity index ofeach section quite different, indicating that individual differences of each section of phytoplanktontypes of functional groups, communities affected by environmental factors influence the pattern ofuneven distribution of species.In wet period, the mean diversity index of river each section2.33, is slightly polluted. Eachsection diversity index between2and3, the physical volume of the cross section of water is slightlypolluted. Diversity index of each section D value changed little, indicating that individualdifferences of each section of phytoplankton functional group types of small algal communitystructure and stability, species distribution pattern is relatively uniform.（5）Algae nutrition index of water quality evaluation results: in the dry season, algaenutrition index was15, classified as moderately polluted. E2, E3, light pollution; E1, the E5forpollution; E4, E6heavy pollution. Wet period and algae nutritional index of24, are heavily polluted.Which E1, E3, E4, E5, E6, heavy pollution, E2light pollution.