| Urban river is an important part of urban aquatic ecological environment.Its water environment quality is closely related to its surrounding land use type and urbanization level.In recent years,the increase of urban area and the deepening of urbanization have had varying degrees of impact on the water environment of urban rivers.In particular,a large number of ecological parks have been built around urban rivers,which not only provide good leisure and sightseeing places for urban residents,but also put forward new topics for urban water environment protection.Therefore,it is of great significance to study the river water environmental quality in different urban areas.Taking two main rivers in Suzhou City,Anhui Province(Tuo river in urban area and Bian river in urban fringe area)as the research object,through the analysis of river water sample test results in wet season for two consecutive years,this paper discussed the hydrochemical characteristics and genetic mechanism of Tuo river and Bian river,and the spectral characteristics and sources of dissolved organic matter.Then the water environment quality evaluation of the two rivers was carried out to provide reference for river water environment management and protection in different urban areas.The main achievemeents were as follows:(1)By analyzing the contents of major components in Tuo river and Bian river in 2019 and 2020,it was found that the changes of anion and cation concentrations in the two rivers were the same in two years.According to the one-way ANOVA,there were some differences in Cl-,SO42-,Na+,Ca2+,Mg2+,TP and COD between Tuo river and Bian river,which indicated that the rivers in different areas of the city had different water quality due to their environmental differences to a certain extent.(2)Based on the analysis of hydrochemical genetic mechanism of Tuo river and Bian river in 2019 and 2020,the hydrochemical of Tuo river and Bian river was mainly affected by rock weathering and human activities;Correlation analysis and self-organizing neural network method were used to reveal the internal relationship between water quality parameters.(3)The test results showed that there was no significant difference in DOC content between Tuo river and Bian river in 2019,and there was a significant difference in DOC content between the two rivers in 2020.The DOC content of Tuo river and Bian river in this year was significantly higher than that in 2019(p<0.05,ANOVA).(4)By comparing the content of fluorescent components,it was found that the content of protein components in Bian river in 2019 was greater than that in Tuo river in 2019;The calculation results of fluorescence index showed that the dissolved organic matter(DOM)of Tuoriver and Bian river in 2019 and 2020 showed strong characteristics of authigenic source.(5)According to the results of fuzzy comprehensive evaluation,the water quality of Tuo river was good in 2019,while that of Bian river was poor,mostly class V water.In 2020,the proportion of class V water in Tuo river water sample was the highest,and the overall water quality was poor;Compared with 2019,the overall water quality of Bian river tends to improve.(6)The results of irrigation water quality evaluation showed that all water samples in Tuo river and Bian river belong to high salt and low alkali,and the SAR of all water samples was less than 18,indicating that the sodium damage of water samples in the study area was low;When MH<50,it can be regarded as suitable for irrigation.All water samples of Tuo river and Bian river exceeded the standard limit in two summers.Therefore,when using Tuo river and Bian river for irrigation,attention should be paid to the impact of magnesium damage on crops.Figure 29 Table 11 References 111... |
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