Changes Of Water Quality Indexes In Jiamusi Section Of The Songhua River And Distribution Characteristics Of Attached Algae

Biomonitoring is using the various reaction information generated by plants or animals in the environment to judge the environmental quality.It is an effective way to reflect the comprehensive quality of the water environment,and it can effectively alleviate the shortage of physical and chemical monitoring technology,which is caused by the complex environment.The periphytic algae are very sensitive to the changes of water environment.The changes in the community structure can reflect the changes of water quality to a certain extent.The periphytic algae have the advantages of small migration,non-toxic and harmless.The water quality evaluation index has a positive effect on the water quality evaluation system of the Jiamusi section of the Songhua River.Five sampling points were set up in the Jiamusi section of the Songhua River.The physical and chemical indicators of the sampling points were measured during the flat and high water periods from 2013 to 2015,During that period,the periphyticalgae werecollected,and the physical,chemical and biological monitoring were carried out.Based on the combination method,not only the spatial and temporal changes of physical and chemical indicators butalso distribution of algae communities in the Jiamusi section of Songhua River were analyzed.At the same time,the correlation between physical and chemical index parameters and living algae was analyzed.The main findings are as follows:By comprehensive analysis of the physical and chemical indicators monitoring data from 2013 to 2015,the results showed that the Jiamusi section of the Songhua River basically meets the surface class IV water standard,and the main stream section will enter the scope of the Class V water standard within a certain period of time.The main pollution index is the permanent index.Chemical oxygen demand and total nitrogen,the main pollution type of Jiamusi River section of Songhua River is organic pollution,and the content of nutrient element N is generally high.Statistical analysis of the periphyticalgae populations and dominant species from 2013 to 2015 found that the algae in the Jiamusi section of the Songhua River mainly consisted of diatoms,green algae and cyanobacteria,with the highest proportion of diatoms,followed by green.Algae and Cyanophyta;Diphtheria is the dominant species in each section of each year;similarity analysis shows that there are large variations in the inter-annual variation and poor stability,in the 2 tributary sections,the number of species is at a low level every year;the density of periphyticalgae in Tangwang River is higher than that of periphyticalgae in the Wutong River.Redundancy analysisof periphyticalgae and environmental factors found that total nitrogen may be the main environmental factor affecting the distribution of periphyticalgae.When Navicula Bory,Navicula Bory sp1 and Cymbella Ag are present,it can be shown to a certain extent that the total nitrogen content in the water environment is low and the water environment quality is relatively good.The presence of Gomphonema parvulum and Navicula simplex indicates to some extent that the total nitrogen content in the water environment is high and there is a risk of eutrophication of the water.